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Keywords:

  • autism;
  • CNV;
  • genetics;
  • two-hit model;
  • compound heterozygosity

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

Autism is a childhood-onset neurodevelopmental disorder with complex genetic mechanism underlying its etiology. Recent studies revealed that a few single de novo copy number variants of genomic DNA (copy number variants [CNVs]) are pathogenic and causal in some sporadic cases, adding support to the hypothesis that some sporadic autism might be caused by single rare mutation with large clinical effect. In this study, we report the detection of two novel private CNVs simultaneously in a male patient with autism. These two CNVs include a microduplication of ∼4.5 Mb at chromosome 4q12-13.1 that was transmitted from his mother and a microdeletion of ∼1.8 Mb at 5q32 that was transmitted from his father. Several genes such as LPHN3, POU4F3, SH3RF2, and TCERG1 mapped to these two regions have psychiatric implications. However, the parents had only mild degree of attention deficit symptoms but did not demonstrate any obvious autistic symptoms or psychopathology. Our findings indicate that each of these two CNVs alone may not be pathogenic enough to cause clinical symptoms in their respective carriers, and hence they can be transmitted within each individual family. However, concomitant presence of these two CNVs might result in the clinical phenotypes of the affected patient reported here. Thus, our report of this family may represent an example to show that two hits of CNV and the presence of compound heterozygosity might be important mechanisms underlying the pathogenesis of autism. © 2012 Wiley Periodicals, Inc.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

Autism is a childhood-onset neurodevelopmental disorder defined by impaired reciprocal social interaction, deficient language development, and the presence of restricted interest and stereotyped behavior. The estimated prevalence of autism and its related disorders (autism spectrum disorders, ASD) in general population worldwide is approximately 1–2.6%, with male predominance [Kogan et al., 2009; Kim et al., 2011]. Autism has a high heritability of more than 90%; the genetic underpinnings of autism are heterogeneous and complex, and may involve multiple genes, gene–gene interactions, and gene–environment interactions [Eapen, 2011; Holt and Monaco, 2011]. The genetic risk factors of autism identified so far range from common variants conferring a small effect to rare mutations that have a high clinical effect [State and Levitt, 2011].

Recent development of array-based comparative genomic hybridization technology has discovered that submicroscopic deletion and duplication of genomic DNA, known as copy number variants (CNVs), contribute a significant role to the genetic etiology of ASD, and up to 10% of patients with ASD were found to have rare de novo CNVs associated with their clinical phenotypes [Sebat et al., 2007; Marshall et al., 2008]. In a genome-wide rare CNV analysis, ASD patients were found to carry a higher global burden of rare CNVs when compared to controls (1.19-fold, P < 0.012) [Pinto et al., 2010]. De novo CNVs co-segregating with disease in a family are usually considered as pathogenic; however, increasing evidence indicates that the clinical relevance of some CNVs found in patients with neurodevelopmental disorders including ASD is not so obvious and more complicated [Girirajan and Eichler, 2010; Mitchell, 2011; Poot et al., 2011]. For example, in a study of recurrent 16p12.1 microdeletion associated with neurodevelopmental delay, Girirajan and colleagues reported that 16p12.1 microdeletion was not fully penetrant and might predispose to an additional CNV and lead to more severe clinical features.

Hence, they suggested a two-hit model might be more generally applicable to neuropsychiatric disorders [Girirajan et al., 2010; Veltman and Brunner, 2010]. In our series of molecular genetic study of autism, we conducted CNV analysis in patients with ASD who were consecutively recruited into our study. During our study, we identified a young male patient diagnosed as autism who simultaneously carried two CNVs that might contribute to his clinical phenotypes. Notably, these two CNVs were inherited from his parents, respectively, who did not have obvious psychopathology.

SUBJECTS AND METHODS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

Subjects

We recruited 315 patients, aged 3–17 (mean ± standard deviation, 9.08 ± 4.20), who met the diagnostic criteria of autistic disorder defined by the Diagnostic and Statistical Manual of Mental Disorders-IV (DSM-IV) from the Children Mental Health Center, Department of Psychiatry, Taiwan University Hospital, Taipei, Taiwan, child psychiatric clinics of private hospitals, and special or resource education programs at nursery schools, kindergartens, primary, and high schools in northern Taiwan into our molecular genetic study of autism project. The clinical diagnosis of autism was confirmed using the Chinese version of the Autism Diagnostic Interview-Revised by qualified child psychiatrists [Chien et al., 2011b; Gau et al., 2010]. The ADI-R interviews of the past behaviors revealed that patients with autism scored 20.31 ± 6.22 in the “qualitative abnormalities in reciprocal social interaction” (cut-off = 10), 14.76 ± 4.28 in the “qualitative abnormalities in communication, verbal” (cut-off = 8), 8.17 ± 3.30 in the “qualitative abnormalities in communication, nonverbal” (cut-off = 7), and 6.93 ± 2.47 in the “restricted, repetitive and stereotyped patterns of behaviors” (cutoff = 3). 93.8% of the patients with autism had abnormal development evident before 30 months of age based on the ADI-R interview and validated by the medical records.

The study protocol was approved by the Research Ethics Committee of National Taiwan University Hospital [ID: 9561709027; ClinicalTrials.gov number, NCT00494754], and written informed consents were obtained from the parents of patients after the procedures were fully explained. All the 315 patients with autism (278 males and 37 females) were recruited for CNV screening. Two CNV databases of Chinese residing in Taiwan were used for comparison [Lin et al., 2008a, 2009]. These two CNV databases contain the CNV information of 300 and 813 anonymous unrelated individuals, respectively. The detailed demographic data are not available.

CNV Analysis

Affymerix Genome-Wide Human SNP Array 6.0 (Affymetrix, Santa Clara, CA) was used for CNV analysis in this study. The SNP 6.0 array contains more than 1.8 million markers including more than 906,600 probes for SNPs and more than 946,000 probes for CNVs. These probes are evenly distributed across the whole genome with median distance between probes of ∼0.7 kb. The microarray experiment was conducted by the National Genotyping Center (Academia Sinica, Taipei, Taiwan) according the protocol provided by the manufacturer. CNVs were called by the computer program Genotyping Console 3.0.2 following the manufacturer's instructions (Affymetrix). Genes involved in the CNVs detected from this study were listed from the annotated gene symbols of the UCSC genome browser (NCBI36/hg 18).

Real-Time Quantitative PCR (RT-qPCR)

RT-qPCR was performed using SYBR Green method and implemented in StepOnePlus Real-Time PCR System according to the manufacturer's protocol (Applied Biosystmes, Forster City, CA). A comparative ΔΔCt method was used to validate the CNV in this study. For quantification of the 4q13.1 duplication, fragments of latrophilin 3 gene (LPHN3, GeneID: 23284) at 4q13.1 and FERM, RhoGEF, and pleckstrin domain protein two gene (FARP2, GeneID: 9855) at 2q37.3, were PCR amplified from the genomic DNA of each individual, respectively. The ΔΔCt of each subject was first obtained by subtracting the Ct of LPHN3 by the Ct of FARP2 of his own DNA, then by ΔCt of a normal control subject. The relative fold change to the normal subject was determined as equation image. Similarly, for quantification of the 5q32 deletion, fragments of leucyl-tRNA synthetase gene (LARS, GeneID: 51520) at 5q32 and metaxin 2 gene (MTX2, GeneID: 10651) at 2q31.1, were PCR amplified from genomic DNA of each individual, respectively. The ΔΔCt of each subject was first obtained by subtracting the Ct of DLGAP2 by the Ct of MTX2 of his own DNA, then by ΔCt of a normal control subject. The relative fold change to the normal subject was determined as equation image. The PCR was carried out in triplicates. The primer sequences, optimal annealing temperature and the size of amplicon are listed in Table I.

Table I. Sequences of Primer, Annealing Temperature (Ta), and the Amplicon Size in the Verification of 4q12-13.1 Duplication and 5q32 Deletion Using Real-Time Quantitative PCR
Gene symbolForward primerReverse primerTa (°C)Size (bp)
LPHN35′-TGGATGGCACAGGATTTGTA-3′5′-CCATCGGTAAGGGGAGGTAT-3′60155
FARP25′-AATGCGATGGCCAGGTATTA-3′5′-ATGAAAGATCTTGCGGCTGT-3′60172
LARS5′-TCATTTTCCTGGAGTGTTGG-3′5′-CAAGCCAATGTTCTGCTTCA-3′60172
MTX25′-AGTATGGGACCTGTGGGTGA-3′5′-AAGACTCCTGAGACTAACACATAACTC-3′60291

RESULTS

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

Proband and Family

The patient, an 18-year-old Taiwanese boy, is the only child of unrelated parents. Regular blood tests, ultrasonic examinations, and one amniocentesis during maternal pregnancy did not reveal any abnormal findings. Despite no maternal infection or exposures to substances such as coffee, alcohol, or tobacco during the pregnancy, his mother suffered from high blood sugar in the third trimester. She took multi-vitamins designed for pregnant woman during gestational age of 25–38 weeks. He was born through cesarean section smoothly due to maternal premature rupture of membrane, at his mother's age as 36 years old and father, 39. He was a full-term baby with body weight of 2,700 g without any remarkable complications during infancy. His parents denied that he had any systemic disease or neuropsychiatric disorders such as epilepsy later in life. He did not have any dysmorphic features, either.

He walked alone at age of 18 months old, and spoke his first word other than papa/mama at age of 5 years old and first sentence after 10 years of age. The patient's language is mainly used to express his basic needs and not for communication. At 2.5 years of age, he was clinically diagnosed with autistic disorder and childhood autism based on the DSM-IV and ICD-10 diagnostic criteria, respectively, by board-certificated child psychiatrists specialized in autism assessments and treatments at an autism early intervention center in Taipei. His major manifestations were: non-meaningful verbal outputs, some echolalia, a lack of social reciprocity, no direct gaze, no response to any verbal stimuli, or gestures meant to catch his attention, and restricted and stereotyped behaviors and activities.

Since the first psychiatric contact, he has received irregular but wide-ranging early intervention programs including speech therapy and occupational therapy at 3–5 years old, followed by special education programs at kindergarten for 1 year. He continued receiving special education programs at a primary school (Grade 1–6) and a junior high (Grade 7–9) in Taipei. He is now 11th grader of a senior high school specialized for mental retardation or autism in Taipei. In addition to typical autistic symptoms, he was found to have high level of hyperactivity, impulsivity, and inattention since the age of 3 and lasting till junior high. These symptoms had apparently impeded the progress of his early intervention, which was recognized by his parents as not effective. However, he has never taken any medication to treat attention deficit and/or hyperactivity disorder (ADHD) symptoms.

At the age of 16.5 years old, his mother was interviewed by using the Chinese version of the ADI-R [Gau et al., 2011] in December 2009. The clinical assessment and ADI-R clearly showed that the past and current symptoms of the patient reached the criteria for autistic disorder (autism) as defined by the DSM-IV and ICD-10. The ADI-R revealed that in the past (current), the patient scored 28 (17) in the “qualitative abnormalities in reciprocal social interaction” area (cut-off = 10), 18 (12) in the “qualitative abnormalities in communication” (cut-off = 8), and 10 (8) in the “restricted, repetitive, stereotyped patterns of behaviors” (cutoff = 3).

His current ADHD symptoms based on the mother reports on the Chinese version of the Swanson, Nolan, and Pelham, version IV scale revealed six items of overt inattention and 1item of overt hyperactivity–impulsivity symptoms according to the DSM-IV ADHD symptom criteria [Gau et al., 2008]. However, based on psychiatric interview using the Chinese version of the Kiddie Epidemiologic Version of the Schedule for Affective Disorders and Schizophrenia [Gau et al., 2005] and clinical assessment by the corresponding author, he had sub-threshold inattention symptoms and severe functional impairment, which did not meet the full DSM-IV ADHD diagnostic criteria. Due to his limited communication ability (only immediate echolalia with a maximum of four to five words in length) and lack of response to gesture or verbal commands, he cannot perform the intelligence like Weschler Intelligence Scale for Children-3rd edition or other neuropsychological tests like the Conner's Continuous Performance Test and Wisconsin Card Sorting Test at the age of 16 years and 3 months old and 18 years old.

His mother and father also received clinical assessments and reported on the Adult Autism Spectrum Quotient (cut-off = 32) as 18 and 22, respectively. Based on clinical assessment, his mother did not have social difficulties, but his father, despite no past and current typical autistic symptoms elicited during interview, was not socially active and spoke slowly providing only simple answers with his mother's assistance. In addition, his father had a history of speech delay that he started his first word at age 5 and progressive hearing loss for the past decade. Using the Chinese version of the Adult Self-Report Inventory-4 [Chien et al., 2011a] to assess a wide range of the DSM-IV psychopathology of the parents, they did not report overt symptoms to meet the DSM-IV diagnostic criteria. However, the mother currently showed sub-threshold inattention and hyperactivity/impulsivity symptoms based on her report on the Adult ADHD Self-Report Scale [Yeh et al., 2008] that were confirmed by the clinical interview. In summary, the patient had typical symptoms of autism and some ADHD symptoms; his parents did not demonstrate any obvious autistic symptoms or DSM-IV psychopathology but the mother had sub-threshold ADHD symptoms and his father had a history of speech delay, gradual hearing impairment in the past decade, and may have some autistic trait in social reciprocity dimension.

Array CGH Analysis

As shown in Figure 1, the proband was found to have an interstitial duplication at chromosome 4q12-13. The 4q12-13 duplication started from the nucleotide position 57884499 and ended at the nucleotide position 62417220, with the size of ∼4.5 Mb. The duplication was inherited from his mother who had the same duplication as shown in Figure 1. The proband was also detected to have an interstitial deletion at chromosome 5q32. The deletion started from the nucleotide position 144752343 and ended at the nucleotide position 146539262, with the size of ∼1.8 Mb (Fig. 2). The deletion was transmitted from his father who was found to have the same deletion as shown in Figure 2.

thumbnail image

Figure 1. Detection of interstitial microduplication of ∼4.5 Mb at chromosome 4q12-13.1 in the proband and his mother using Affymerix Genome-Wide Human SNP Array 6.0, arrow indicates the location of the duplication. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmg.b]

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thumbnail image

Figure 2. Detection of interstitial microdeletion of ∼1.8 Mb at 5q32 in the proband and his father using Affymerix Genome-Wide Human SNP Array 6.0, arrow indicates the location of the deletion. [Color figure can be seen in the online version of this article, available at http://wileyonlinelibrary.com/journal/ajmg.b]

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RT-qPCR

Using the RT-qPCR of genomic DNA as a supplementary confirmation method for CNVs detected in this family, we found that the fold changes of LPHN3 at the 4q13.1 duplication as normalized by the FARP2 at 2q37.3 in the proband and his mother relative to the control subject were approximately 1.5, while his father had the fold change of approximately 1.0 (Fig. 3a). Regarding the 5q32 deletion, we found that the fold changes of LARS at the 5q32 as normalized by the MTX2 at 2q31.1 in the proband and his father relative to the control subject were approximately 0.5, while his mother has the fold change of approximately 1.0 (Fig. 3b).

thumbnail image

Figure 3. Verification of 4q12-13.1 duplication (a) and 5q32 deletion (b) using RT-qPCR of genomic DNA. P indicates proband; F indicates father; M indicates mother; C1, C2, C3, and C4 indicate unaffected control subjects.

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DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

The study reported two concurrent submicroscopic CNVs, an interstitial duplication of ∼4.5 Mb at chromosome 4q12-13 and an interstitial deletion of ∼1.8 Mb at chromosome 5q32 in a young male patient with clinical diagnosis of autism since early childhood. Family study showed that the 4q12-13 duplication was transmitted from his mother, while the 5q32 deletion was inherited from his father. To our knowledge, these two CNVs were not found in the databases of genome variations, including UCSC Genome Browser (http://genome.ucsc.edu/cgi-bin/hgGateway), ENSEMBLE (http://www.ensembl.org/index.html), and Toronto DGV (Database of Genomic variants, http://projetcs.tcag.ca/variants) till the submission of this article. They were also not detected in the public genomic variation databases in Taiwanese population [Lin et al., 2008b, 2009]. We have tried to map the breakpoint sequences of these CNVs, but in vain. Hence, it is difficult to infer the mechanism of the occurrence of these two CNVs at the present time.

The 4q12-13 duplication encompasses three genes (based on Build 36.3), including SRIL, LPHN3, and LOC727997. Both SRIL and LOC727997 are inferred pseudogenes, while the LPHN3 is a validated gene coding for latrophilin 3, a member of the latrophilin subfamily of G-protein coupled receptors. LPHN3 is specifically expressed in brain tissue [Martinez et al., 2011]. Recently, a linkage analysis on multigenerational families in an isolated population followed by association study in five samples revealed that LPHN3 was associated with ADHD and predicted the effectiveness to stimulant medication [Arcos-Burgos et al., 2010]. The association of LPHN3 and ADHD was replicated in samples of adult ADHD [Ribases et al., 2011], further supporting the involvement of LPHN3 in the neurobiology of ADHD across lifespan [Franke et al., 2011]. Moreover, a recent study demonstrated that a cooperative interaction of LPHN3 and 11q doubles the risk of ADHD [Jain et al., 2011]. In our study, the patient had overt ADHD symptoms, while his mother who also carried the 4q12-13 duplication currently still had sub-threshold ADHD symptoms at her age of 53 according to her report on the Adult ADHD Self-Report Scale [Yeh et al., 2008] and the clinical assessment by the corresponding author. It is likely that the ADHD symptoms of the mother can be attributed to the duplication of LPHN3 gene, while the more prominent ADHD symptoms found in the patient can be attributed to the interaction between LPHN3 and other genes, especially those in the 5q32 deletion region.

A total of 13 genes were mapped to the 5q32 deletion region (based on Build 36.3), including LOC650866, PRELID2, LOC643226, SH3RF2, PLAC8L1, LARS, RBM27, POU4F3, TCERG1, GPR151, and PPP2R2B. LOC650866 is a pseudogene and LOC650866 is a provisional protein-coding gene, while the rest are validated protein-coding genes. PPP2R2B encodes a brain-enriched regulatory subunit B of protein phosphatase 2A (PP2A) that is involved in various cellular functions, signaling pathways, and apoptosis [Janssens and Goris, 2001; Lechward et al., 2001; Van Hoof and Goris, 2003]. Expansion of CAG repeat at the promoter region of the PPP2R2B is associated with autosomal dominant spinocerebellar ataxia type 12 (SCA12) [Holmes et al., 1999], a late-onset, slowly progressive neurodegenerative disease characterized by action tremor, hyperreflexia, ataxia, and cortical dysfunction [O'Hearn et al., 2012]. The CAG repeat functions as a cis element to up-regulate the expression of PPP2R2B. Increased number of CAG repeat is associated with elevated PPP2R2B expression, while deletion of CAG repeat down-regulates the expression PPP2R2B [Lin et al., 2010]. Hence, the pathogenesis of SCA12 can be attributed to the increased PPP2R2B expression in the brain. In contrast, shorter CAG repeats (n = 5–7) of the PPP2R2B has lower reporter gene activities than the longer CAG repeat (n = 10, 13, and 16), and associate with Alzheimer's disease and essential tremor [Chen et al., 2009; Kimura et al., 2011]. Together, these studies indicate that strict regulation of the PPP2R2B expression is essential for the healthy brain. Hence, it is likely that haploinsufficiency of the PPP2R2B in our patient may lead to decreased expression of PPP2R2B in his brain and contribute to his clinical phenotypes.

POU4F3 encodes the POU domain, class 4, transcription factor 3 that is a member of POU family of transcription factors, and is expressed mainly in inner ear hair cells. It plays an essential role for the normal development and proper function of inner ear hair cells. Mutations of the POU4F3 are associated with an adult-onset, non-syndromic, autosomal dominant progressive hearing impairment in humans [Vahava et al., 1998; Collin et al., 2008; de Heer et al., 2009; Lee et al., 2010]. So far, the patient was not found to have hearing problem, but his father was found to have progressive hearing loss, which can be attributed to the haploinsufficiency of the POU4F3.

PRELID2 encodes protein of relevant evolutionary and lymphoid interest domain containing protein 2. The function of this protein is still unclear, but it is believed to be a mitochondrial protein and required for mitochondrial respiratory ability. A study reported that this gene was conserved, and widely and persistently expressed in mouse embryonic development, suggesting that the Prelid2 gene is involved in mouse embryonic development [Gao et al., 2009]. SH3RF2 encodes SH3 domain containing ring finger 2 protein that was found as a region-specific molecular marker of nucleus accumbens of human brain [Wilhelm et al., 2012]. Sh3rg2 was demonstrated to promote cell survival by ring-mediated proteasomal degradation of the c-Jun N-terminal kinase scaffold POSH (Plenty of SH3s) protein in many cell types [Wilhelm et al., 2012]. PLAC8L1 encodes placenta-specific gene 8 protein (PLAC8)-like 1 protein; however, its function is unclear. GPR151 encodes G protein-coupled receptor 151 with unclear function. LARS encodes cytoplasmic leucyl-tRNA synthetase that forms a macromoleuclar protein complex with other aminoacyl-tRNA synthetases and interacting proteins to catalyze the attachment of their cognate amino acid to the 3′-end of the specific tRNA [Park et al., 2010]. It is also involved in editing non-cognate amino acid transfer [Chen et al., 2011]. However, the clinical relevance of haploinsufficiency of these genes remains to be studied.

TCERG1 encodes transcription elongation regulator 1 that regulates transcriptional elongation and pre-mRNA splicing. It also plays a prevalent role in mRNA processing [Pearson et al., 2008]. TECRG1 also interacts with huntingtin protein and involves the pathogenesis of Huntington's disease. It was found to modify the age-of-onset of Huntington's disease [Holbert et al., 2001]. Expression of TECRG1 can delay striatal cell death induced by mutant huntingtin neurotoxicity in transgenic mice [Arango et al., 2006]. Together, these studies suggest that TECRG1 might play an important role in neurons, and haploinsufficiency of this gene might have relevance to the clinical phenotypes of this patient.

Autism is a complex disease with highly heterogeneous genetic underpinnings. Although recent studies have revealed that some de novo CNVs were pathogenic and causal in some sporadic cases, increasing evidence suggests that some CNVs are inherited and their clinical relevance may not be straightforward [Girirajan and Eichler, 2010; Mitchell, 2011; Poot et al., 2011]. In the present study, the parents who carried the respective 5q13 duplication and 4q32 deletion did not have obvious psychopathology, suggesting that each of these two CNVs alone may not be pathogenic enough to cause clinical phenotypes, while the concurrence of these two CNVs in the affected patient suggest that interactions among genes involved in these two CNVs may lead to clinical phenotypes. Our findings are in line with the hypothesis that two-hit model might be more generally applicable to neuropsychiatric disorders as proposed by Girirajan and colleagues [Girirajan et al., 2010; Veltman and Brunner, 2010].

In addition to the two-hit model, our findings are also in line with the compound heterozygosity model of autism. In a genetic study of high-functioning, idiopathic ASD, Schaaf et al. [2011] reported that in addition of de novo rare mutations, patients with ASD had a significantly higher proportion of multiple events of compound heterozygosity than control subjects, suggesting compound heterozygosity is a new potential mechanism in the pathogenesis of ASD.

Together, our findings support that both the two-hit CNV model and the compound heterozygosity model as complex genetic mechanisms underlying autism. Nevertheless, it is also possible that the clinical presentations of the affected patient were precipitated by other genetic factors or environmental factors in addition to these two CNVs.

Acknowledgements

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES

This work was supported by grants from National Science Council (NSC96-3112-B-002-033, NSC97-3112-B-002-009, NSC98-3112-B-002-004, and NSC 99-3112-B-002-036), National Taiwan University (10R81918-03), and intramural grant from National Health Research Institutes, Taiwan.

REFERENCES

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. SUBJECTS AND METHODS
  5. RESULTS
  6. DISCUSSION
  7. Acknowledgements
  8. REFERENCES
  • Arango M, Holbert S, Zala D, Brouillet E, Pearson J, Regulier E, Thakur AK, Aebischer P, Wetzel R, Deglon N, Neri C. 2006. CA150 expression delays striatal cell death in overexpression and knock-in conditions for mutant huntingtin neurotoxicity. J Neurosci 26(17):46494659.
  • Arcos-Burgos M, Jain M, Acosta MT, Shively S, Stanescu H, Wallis D, Domene S, Velez JI, Karkera JD, Balog J, Berg K, Kleta R, Gahl WA, Roessler E, Long R, Lie J, Pineda D, Londono AC, Palacio JD, Arbelaez A, Lopera F, Elia J, Hakonarson H, Johansson S, Knappskog PM, Haavik J, Ribases M, Cormand B, Bayes M, Casas M, Ramos-Quiroga JA, Hervas A, Maher BS, Faraone SV, Seitz C, Freitag CM, Palmason H, Meyer J, Romanos M, Walitza S, Hemminger U, Warnke A, Romanos J, Renner T, Jacob C, Lesch KP, Swanson J, Vortmeyer A, Bailey-Wilson JE, Castellanos FX, Muenke M. 2010. A common variant of the latrophilin 3 gene, LPHN3, confers susceptibility to ADHD and predicts effectiveness of stimulant medication. Mol Psychiatry 15(11):10531066.
  • Chen CM, Hou YT, Liu JY, Wu YR, Lin CH, Fung HC, Hsu WC, Hsu Y, Lee SH, Hsieh-Li HM, Su MT, Chen ST, Lane HY, Lee-Chen GJ. 2009. PPP2R2B CAG repeat length in the Han Chinese in Taiwan: Association analyses in neurological and psychiatric disorders and potential functional implications. Am J Med Genet Part B 150B(1):124129.
  • Chen X, Ma JJ, Tan M, Yao P, Hu QH, Eriani G, Wang ED. 2011. Modular pathways for editing non-cognate amino acids by human cytoplasmic leucyl-tRNA synthetase. Nucleic Acids Res 39(1):235247.
  • Chien YL, Gau SS, Gadow KD. 2011a. Sex difference in the rates and co-occurring conditions of psychiatric symptoms in incoming college students in Taiwan. Compr Psychiatry 52(2):195207.
  • Chien YL, Wu YY, Chiu YN, Liu SK, Tsai WC, Lin PI, Chen CH, Gau SS, Chien WH. 2011b. Association study of the CNS patterning genes and autism in Han Chinese in Taiwan. Prog Neuropsychopharmacol Biol Psychiatry 35(6):15121517.
  • Collin RW, Chellappa R, Pauw RJ, Vriend G, Oostrik J, van Drunen W, Huygen PL, Admiraal R, Hoefsloot LH, Cremers FP, Xiang M, Cremers CW, Kremer H. 2008. Missense mutations in POU4F3 cause autosomal dominant hearing impairment DFNA15 and affect subcellular localization and DNA binding. Hum Mutat 29(4):545554.
  • de Heer AM, Huygen PL, Collin RW, Kremer H, Cremers CW. 2009. Mild and variable audiometric and vestibular features in a third DFNA15 family with a novel mutation in POU4F3. Ann Otol Rhinol Laryngol 118(4):313320.
  • Eapen V. 2011. Genetic basis of autism: Is there a way forward? Curr Opin Psychiatry 24(3):226236.
  • Franke B, Faraone SV, Asherson P, Buitelaar J, Bau CH, Ramos-Quiroga JA, Mick E, Grevet EH, Johansson S, Haavik J, Lesch KP, Cormand B, Reif A. 2011. The genetics of attention deficit/hyperactivity disorder in adults, a review. Mol Psychiatry, 128 [Epub ahead of print]. DOI: 10.1038/mp.2011.138
  • Gao M, Liu Q, Zhang F, Han Z, Gu T, Tian W, Chen Y, Wu Q. 2009. Conserved expression of the PRELI domain containing 2 gene (Prelid2) during mid-later-gestation mouse embryogenesis. J Mol Histol 40(3):227233.
  • Gau SS, Chong MY, Chen TH, Cheng AT. 2005. A 3-year panel study of mental disorders among adolescents in Taiwan. Am J Psychiatry 162(7):13441350.
  • Gau SS, Shang CY, Liu SK, Lin CH, Swanson JM, Liu YC, Tu CL. 2008. Psychometric properties of the Chinese version of the Swanson, Nolan, and Pelham, version IV scale—Parent form. Int J Methods Psychiatr Res 17(1):3544.
  • Gau SS, Chou MC, Lee JC, Wong CC, Chou WJ, Chen MF, Soong WT, Wu YY. 2010. Behavioral problems and parenting style among Taiwanese children with autism and their siblings. Psychiatry Clin Neurosci 64(1):7078.
  • Gau SS-F, Lee C-M, Lai M-C, Chiu Y-N, Huang Y-F, Kao J-D, Wu Y-Y. 2011. Psychometric properties of the Chinese version of the Social Communication Questionnaire. Res Autism Spectr Disord 5(2):809818.
  • Girirajan S, Eichler EE. 2010. Phenotypic variability and genetic susceptibility to genomic disorders. Hum Mol Genet 19(R2):R176R187.
  • Girirajan S, Rosenfeld JA, Cooper GM, Antonacci F, Siswara P, Itsara A, Vives L, Walsh T, McCarthy SE, Baker C, Mefford HC, Kidd JM, Browning SR, Browning BL, Dickel DE, Levy DL, Ballif BC, Platky K, Farber DM, Gowans GC, Wetherbee JJ, Asamoah A, Weaver DD, Mark PR, Dickerson J, Garg BP, Ellingwood SA, Smith R, Banks VC, Smith W, McDonald MT, Hoo JJ, French BN, Hudson C, Johnson JP, Ozmore JR, Moeschler JB, Surti U, Escobar LF, El-Khechen D, Gorski JL, Kussmann J, Salbert B, Lacassie Y, Biser A, McDonald-McGinn DM, Zackai EH, Deardorff MA, Shaikh TH, Haan E, Friend KL, Fichera M, Romano C, Gecz J, DeLisi LE, Sebat J, King MC, Shaffer LG, Eichler EE. 2010. A recurrent 16p12.1 microdeletion supports a two-hit model for severe developmental delay. Nat Genet 42(3):203209.
  • Holbert S, Denghien I, Kiechle T, Rosenblatt A, Wellington C, Hayden MR, Margolis RL, Ross CA, Dausset J, Ferrante RJ, Neri C. 2001. The Gln-Ala repeat transcriptional activator CA150 interacts with huntingtin: Neuropathologic and genetic evidence for a role in Huntington's disease pathogenesis. Proc Natl Acad Sci USA 98(4):18111816.
  • Holmes SE, O'Hearn EE, McInnis MG, Gorelick-Feldman DA, Kleiderlein JJ, Callahan C, Kwak NG, Ingersoll-Ashworth RG, Sherr M, Sumner AJ, Sharp AH, Ananth U, Seltzer WK, Boss MA, Vieria-Saecker AM, Epplen JT, Riess O, Ross CA, Margolis RL. 1999. Expansion of a novel CAG trinucleotide repeat in the 5' region of PPP2R2B is associated with SCA12. Nat Genet 23(4):391392.
  • Holt R, Monaco AP. 2011. Links between genetics and pathophysiology in the autism spectrum disorders. EMBO Mol Med 3(8):438450.
  • Jain M, Velez JI, Acosta MT, Palacio LG, Balog J, Roessler E, Pineda D, Londono AC, Palacio JD, Arbelaez A, Lopera F, Elia J, Hakonarson H, Seitz C, Freitag CM, Palmason H, Meyer J, Romanos M, Walitza S, Hemminger U, Warnke A, Romanos J, Renner T, Jacob C, Lesch KP, Swanson J, Castellanos FX, Bailey-Wilson JE, Arcos-Burgos M, Muenke M. 2011. A cooperative interaction between LPHN3 and 11q doubles the risk for ADHD. Mol Psychiatry, 17 [Epub ahead of print]. DOI: 10.1038/mp.2011.59
  • Janssens V, Goris J. 2001. Protein phosphatase 2A: A highly regulated family of serine/threonine phosphatases implicated in cell growth and signalling. Biochem J 353(Pt 3):417439.
  • Kim YS, Leventhal BL, Koh YJ, Fombonne E, Laska E, Lim EC, Cheon KA, Kim SJ, Kim YK, Lee H, Song DH, Grinker RR. 2011. Prevalence of autism spectrum disorders in a total population sample. Am J Psychiatry 168(9):904912.
  • Kimura R, Morihara T, Kudo T, Kamino K, Takeda M. 2011. Association between CAG repeat length in the PPP2R2B gene and Alzheimer disease in the Japanese population. Neurosci Lett 487(3):354357.
  • Kogan MD, Blumberg SJ, Schieve LA, Boyle CA, Perrin JM, Ghandour RM, Singh GK, Strickland BB, Trevathan E, van Dyck PC. 2009. Prevalence of parent-reported diagnosis of autism spectrum disorder among children in the US, 2007. Pediatrics 124(5):13951403.
  • Lechward K, Awotunde OS, Swiatek W, Muszynska G. 2001. Protein phosphatase 2A: Variety of forms and diversity of functions. Acta Biochim Pol 48(4):921933.
  • Lee HK, Park HJ, Lee KY, Park R, Kim UK. 2010. A novel frameshift mutation of POU4F3 gene associated with autosomal dominant non-syndromic hearing loss. Biochem Biophys Res Commun 396(3):626630.
  • Lin CH, Li LH, Ho SF, Chuang TP, Wu JY, Chen YT, Fann CS. 2008a. A large-scale survey of genetic copy number variations among Han Chinese residing in Taiwan. BMC Genetics 9:92.
  • Lin CH, Li LH, Ho SF, Chuang TP, Wu JY, Chen YT, Fann CS. 2008b. A large-scale survey of genetic copy number variations among Han Chinese residing in Taiwan. BMC Genet 9:92.
  • Lin CH, Lin YC, Wu JY, Pan WH, Chen YT, Fann CS. 2009. A genome-wide survey of copy number variations in Han Chinese residing in Taiwan. Genomics 94(4):241246.
  • Lin CH, Chen CM, Hou YT, Wu YR, Hsieh-Li HM, Su MT, Lee-Chen GJ. 2010. The CAG repeat in SCA12 functions as a cis element to up-regulate PPP2R2B expression. Hum Genet 128(2):205212.
  • Marshall CR, Noor A, Vincent JB, Lionel AC, Feuk L, Skaug J, Shago M, Moessner R, Pinto D, Ren Y, Thiruvahindrapduram B, Fiebig A, Schreiber S, Friedman J, Ketelaars CE, Vos YJ, Ficicioglu C, Kirkpatrick S, Nicolson R, Sloman L, Summers A, Gibbons CA, Teebi A, Chitayat D, Weksberg R, Thompson A, Vardy C, Crosbie V, Luscombe S, Baatjes R, Zwaigenbaum L, Roberts W, Fernandez B, Szatmari P, Scherer SW. 2008. Structural variation of chromosomes in autism spectrum disorder. Am J Hum Genet 82(2):477488.
  • Martinez AF, Muenke M, Arcos-Burgos M. 2011. From the black widow spider to human behavior: Latrophilins, a relatively unknown class of G protein-coupled receptors, are implicated in psychiatric disorders. Am J Med Genet Part B 156B(1):110.
  • Mitchell KJ. 2011. The genetics of neurodevelopmental disease. Curr Opin Neurobiol 21(1):197203.
  • O'Hearn E, Holmes SE, Margolis RL. 2012. Spinocerebellar ataxia type 12. Handb Clin Neurol 103:535547.
  • Park SG, Choi EC, Kim S. 2010. Aminoacyl-tRNA synthetase-interacting multifunctional proteins (AIMPs): A triad for cellular homeostasis. IUBMB Life 62(4):296302.
  • Pearson JL, Robinson TJ, Munoz MJ, Kornblihtt AR, Garcia-Blanco MA. 2008. Identification of the cellular targets of the transcription factor TCERG1 reveals a prevalent role in mRNA processing. J Biol Chem 283(12):79497961.
  • Pinto D, Pagnamenta AT, Klei L, Anney R, Merico D, Regan R, Conroy J, Magalhaes TR, Correia C, Abrahams BS, Almeida J, Bacchelli E, Bader GD, Bailey AJ, Baird G, Battaglia A, Berney T, Bolshakova N, Bolte S, Bolton PF, Bourgeron T, Brennan S, Brian J, Bryson SE, Carson AR, Casallo G, Casey J, Chung BH, Cochrane L, Corsello C, Crawford EL, Crossett A, Cytrynbaum C, Dawson G, de Jonge M, Delorme R, Drmic I, Duketis E, Duque F, Estes A, Farrar P, Fernandez BA, Folstein SE, Fombonne E, Freitag CM, Gilbert J, Gillberg C, Glessner JT, Goldberg J, Green A, Green J, Guter SJ, Hakonarson H, Heron EA, Hill M, Holt R, Howe JL, Hughes G, Hus V, Igliozzi R, Kim C, Klauck SM, Kolevzon A, Korvatska O, Kustanovich V, Lajonchere CM, Lamb JA, Laskawiec M, Leboyer M, Le Couteur A, Leventhal BL, Lionel AC, Liu XQ, Lord C, Lotspeich L, Lund SC, Maestrini E, Mahoney W, Mantoulan C, Marshall CR, McConachie H, McDougle CJ, McGrath J, McMahon WM, Merikangas A, Migita O, Minshew NJ, Mirza GK, Munson J, Nelson SF, Noakes C, Noor A, Nygren G, Oliveira G, Papanikolaou K, Parr JR, Parrini B, Paton T, Pickles A, Pilorge M, Piven J, Ponting CP, Posey DJ, Poustka A, Poustka F, Prasad A, Ragoussis J, Renshaw K, Rickaby J, Roberts W, Roeder K, Roge B, Rutter ML, Bierut LJ, Rice JP, Salt J, Sansom K, Sato D, Segurado R, Sequeira AF, Senman L, Shah N, Sheffield VC, Soorya L, Sousa I, Stein O, Sykes N, Stoppioni V, Strawbridge C, Tancredi R, Tansey K, Thiruvahindrapduram B, Thompson AP, Thomson S, Tryfon A, Tsiantis J, Van Engeland H, Vincent JB, Volkmar F, Wallace S, Wang K, Wang Z, Wassink TH, Webber C, Weksberg R, Wing K, Wittemeyer K, Wood S, Wu J, Yaspan BL, Zurawiecki D, Zwaigenbaum L, Buxbaum JD, Cantor RM, Cook EH, Coon H, Cuccaro ML, Devlin B, Ennis S, Gallagher L, Geschwind DH, Gill M, Haines JL, Hallmayer J, Miller J, Monaco AP, Nurnberger JI Jr, Paterson AD, Pericak-Vance MA, Schellenberg GD, Szatmari P, Vicente AM, Vieland VJ, Wijsman EM, Scherer SW, Sutcliffe JS, Betancur C., 2010. Functional impact of global rare copy number variation in autism spectrum disorders. Nature 466: (7304) 368372.
  • Poot M, van der Smagt JJ, Brilstra EH, Bourgeron T. 2011. Disentangling the myriad genomics of complex disorders, specifically focusing on autism, epilepsy, and schizophrenia. Cytogenet Genome Res 135(3–4):228240.
  • Ribases M, Ramos-Quiroga JA, Sanchez-Mora C, Bosch R, Richarte V, Palomar G, Gastaminza X, Bielsa A, Arcos-Burgos M, Muenke M, Castellanos FX, Cormand B, Bayes M, Casas M. 2011. Contribution of LPHN3 to the genetic susceptibility to ADHD in adulthood: A replication study. Genes Brain Behav 10(2):149157.
  • Schaaf CP, Sabo A, Sakai Y, Crosby J, Muzny D, Hawes A, Lewis L, Akbar H, Varghese R, Boerwinkle E, Gibbs RA, Zoghbi HY. 2011. Oligogenic heterozygosity in individuals with high-functioning autism spectrum disorders. Hum Mol Genet 20(17):33663375.
  • Sebat J, Lakshmi B, Malhotra D, Troge J, Lese-Martin C, Walsh T, Yamrom B, Yoon S, Krasnitz A, Kendall J, Leotta A, Pai D, Zhang R, Lee YH, Hicks J, Spence SJ, Lee AT, Puura K, Lehtimaki T, Ledbetter D, Gregersen PK, Bregman J, Sutcliffe JS, Jobanputra V, Chung W, Warburton D, King MC, Skuse D, Geschwind DH, Gilliam TC, Ye K, Wigler M. 2007. Strong association of de novo copy number mutations with autism. Science 316(5823):445449.
  • State MW, Levitt P. 2011. The conundrums of understanding genetic risks for autism spectrum disorders. Nat Neurosci 14(12):14991506.
  • Vahava O, Morell R, Lynch ED, Weiss S, Kagan ME, Ahituv N, Morrow JE, Lee MK, Skvorak AB, Morton CC, Blumenfeld A, Frydman M, Friedman TB, King MC, Avraham KB. 1998. Mutation in transcription factor POU4F3 associated with inherited progressive hearing loss in humans. Science 279(5358):19501954.
  • Van Hoof C, Goris J. 2003. Phosphatases in apoptosis: To be or not to be, PP2A is in the heart of the question. Biochim Biophys Acta 1640(2–3):97104.
  • Veltman JA, Brunner HG. 2010. Understanding variable expressivity in microdeletion syndromes. Nat Genet 42(3):192193.
  • Wilhelm M, Kukekov NV, Schmit TL, Biagas KV, Sproul AA, Gire S, Maes ME, Xu Z, Greene LA. 2012. Sh3rf2/POSHER protein promotes cell survival by ring-mediated proteasomal degradation of the c-Jun N-terminal kinase scaffold posh (plenty of SH3s) protein. J Biol Chem 287(3):22472256.
  • Yeh CB, Gau SS, Kessler RC, Wu YY. 2008. Psychometric properties of the Chinese version of the adult ADHD self-report scale. Int J Methods Psychiatr Res 17(1):4554.