Get access

Amyoplasia revisited

Authors

  • Judith G. Hall,

    Corresponding author
    1. Departments of Medical Genetics and Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, Canada
    • Correspondence to:

      Judith G. Hall, OC, MD, FRSC, FCAHS, Department of Medical Genetics and Pediatrics, BC Children's Hospital, 4500 Oak Street, Room C234, Vancouver, BC, Canada V6H 3N1.

      E-mail: jhall@cw.bc.ca

    Search for more papers by this author
  • Kimberly A. Aldinger,

    1. Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
    Search for more papers by this author
  • Kimi I. Tanaka

    1. Departments of Medical Genetics and Pediatrics, University of British Columbia and BC Children's Hospital, Vancouver, Canada
    Search for more papers by this author

  • Conflict of interest: none.

ABSTRACT

Amyoplasia is a specific type and the most common form of arthrogryposis (multiple congenital contractures). It is a clinical diagnosis at this time. Care should be used making the diagnosis because of the implications for recurrence, natural history, associated anomalies, and both etiology and pathogenesis. We reviewed over 600 published reports and 2,500 individual records to identify the 560 individuals reported here. Affected limbs had characteristic positions with fatty–fibrous replacement of muscle. Upper limb involvement was usually characterized by extended elbows. Lower limbs were held in various positions at birth; however, equinovarus positioning of feet was almost always present. Symmetric involvement was common. Among 560 affected individuals, subtypes were identified: four-limb symmetric involvement (331/560 = 55.9%), severe involvement (41/560 = 7.3%), three-limb involvement (27/560 = 4.8%), upper limb only Amyoplasia (ULA; 94/560 = 16.8%), and lower limb only Amyoplasia (LLA; 25/560 = 15.5%). Discordant monozygotic twinning was increased, occurring in 6.6% (37/560; OR 10.9). A variety of additional anomalies were seen, attributed to apparent vascular compromise. Gastrointestinal vascular compromise-type anomalies were present in 9.1% (51/560), trunk muscle defects in another 2.7% (15/560), digit compromise in 12.1% (68/560), constriction rings in 4.3% (24/560), and perinatal long bone fractures in 10.5% (59/560). Although prenatal ultrasound became the standard of care in 1990, only about one quarter of affected pregnancies were diagnosed prenatally since 1990. Amyoplasia appears to be completely sporadic. Novel pathogenetic mechanisms for the congenital anomalies seen in Amyoplasia need to be identified. © 2014 Wiley Periodicals, Inc.

Ancillary