Word smithing in medical genetics


  • M. Michael Cohen Jr.

    Corresponding author
    1. Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
    • Department of Pediatrics, Faculty of Medicine, Dalhousie University, 5981 University Avenue, Halifax, Nova Scotia, Canada B3H 1W2.
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  • This article titled “Word Smithing in Medical Genetics” is dedicated to my good friend Mason Barr Jr. Professor Emeritus of Pediatrics, Obstetrics, and Pathology at the University of Michigan Medical Center in Ann Arbor.

  • How to Cite this Article: Cohen MM Jr. 2010. Word smithing in medical genetics. Am J Med Genet Part A 152A:1–3.


Certain terms used in medical genetics and more often in other medical fields are in need of clarification. The terms cited are frequently misunderstood, mispronounced, and/or misspelled. The discussion includes two Latin-derived terms (genua valga and calvaria), one Greek-derived term (apoptosis), one gene-derived term (RUNX), one syndromic eponym (Kartagener syndrome), and three vascular eponyms (Klippel–Trenaunay syndrome, Parkes Weber syndrome, and Kasabach–Merritt phenomenon). © 2009 Wiley-Liss, Inc.


The terms clarified in this article are used not only in medical genetics and pediatrics, but very often in other medical fields. Quite often they are misunderstood, mispronounced, and/or misspelled.


The Problem With Genu Valgum

The term genu valgum is derived from Latin. Genu is a neuter noun than means “knee” and valgum is the neuter adjective that means “twisted.” [Levine et al., 1967]. Twisted knee can be translated as “knock-knee” or “outwardly deviated tibia.” In medical articles, the term “genu valgum” is commonly used. However, that refers to only one knee, when most often both knees have outwardly deviated tibiae, in which case the proper term should be the plural form “genua valga.”

The Problem With Calvarium

The term “calvarium” has been used in medical textbooks and articles through the years and has been taught to medical students by anatomy faculty as well. The term “calvarium” is incorrect and should never be used. The correct term is the Latin feminine word calvaria. The correct plural word is calvariae [Levine et al., 1967].


Incorrect Pronunciation of the Term Apoptosis

The term apoptosis, meaning programmed cell death, was first introduced by Kerr et al. 1972, who attributed the term to James Cormack, a Professor of Greek at the University of Aberdeen. Apoptosis is derived from Greek and means “falling off” as with petals from flowers or leaves from trees. Because it was a type of “programmed cell death” in plants, it seemed reasonable to apply the term to animal cells.

In various articles given at meeting over the years, I have heard the word apoptosis mispronounced as “a-pop-tosis” To understand the proper pronunciation, one need only understand how the word ptosis is pronounced! Nobody would pronounce this as “pa-tosis.” We all know that the p is silent so the pronunciation is actually “tosis.” The same applies to apoptosis, being “apo + ptosis.” There is no “pop” in it whatsoever.


RUNX Genes

In November of 1999, the Nomenclature Committee of the Human Genome Organization (HUGO) adopted the term “RUNX” to refer to genes encoding the Runt-related proteins based on a panel of eight investigators responsible for cloning the chromosomal breakpoints or cDNAs encoding the genes [van Wijnen et al., 2004]. On one of my many trips to Japan, I spent a day at the University of Kyoto Medical School with Professor Yoshiaki Ito (now at the University of Singapore), who had determined the functional consequences of mutated RUNX3 [Cohen, 2009]. On the HUGO committee he had supported RUNX3 to replace CBFA3 on the HUGO committee [van Wijnen et al., 2004]. He pronounced it RUNX3 (i.e., “RUNKS three”), which is the correct pronunciation. In contrast, I have heard RUNX mispronounced at medical meetings very commonly as RUN-X1, RUN-X2, and RUN-X3 (the word “Run” as in “to run” followed by the letter X and the number), which is totally incorrect.


Kartagener Syndrome

Kartagener syndrome has autosomal recessive inheritance and is characterized by primary ciliary dyskinesia and situs inversus of the viscera. Mutations in the gene DNAI1, which maps to 9p21-p13, cause Kartagener syndrome [OMIM 244400, 2009].

Manes Kartagener (1879–1975] was born in Czechoslovakia where his father was a rabbi. He had an outstanding medical career in Zurich. Besides, his outstanding medical career with a special interest in cardiology and respiratory medicine, he was knowledgeable in biochemistry and mathematics (Fig. 1) [Beighton and Beighton, 1986].

Figure 1.

Manes Kartagener (Courtesy of the late H-R Wiedemann).

Kartagener's name is frequently mispronounced as “Kar-taj′-ener” with accent on the second syllable and a soft “g” which sounds like“j” The proper pronunciation is with the accent on the first syllable and a hard “g” in the third syllable: “Kart′-a-gahner.”


Klippel–Trenaunay Syndrome

Klippel–Trenaunay syndrome is very commonly misdiagnosed in the literature [Whelan et al., 1995; Ceballos-Quintal et al., 1996; Berry et al., 1998]. See Cohen 2006 for more details. Diagnosis is assured when a capillary malformation is studded with lymphatic vesicles. Misguided diagnostic criteria are common [e.g., Oduber et al., 2008]. The name Trenaunay very commonly has an acute accent placed over the e (é) in the literature (Trénaunay) despite the fact that Trenaunay published in French medical journals and never used an acute accent [Klippel and Trenaunay, 1900] in any of his publications.

Klippel–Trenaunay–Weber Syndrome Versus Parkes Weber Syndrome

Klippel–Trenaunay syndrome and Parkes Weber syndrome are two separate disorders that behave differently. There is no Klippel–Trenaunay–Weber syndrome despite the many articles by that title. See Cohen 2000, 2006 for review. Table I contrasts the many differences between Klippel–Trenaunay syndrome and Parkes Weber syndrome.

Table I. Comparison Between Klippel–Trenaunay Syndrome and Parkes Weber Syndrome
 Klippel–Trenaunay syndromeParkes Weber syndrome
  1. From Cohen 2006.

Types of vascular malformationsSlow flow; capillary, lymphatic, venousFast flow; capillary; arterial; venous
Color of cutaneous malformationsBluish-to-purplishPink and diffuse
Arteriovenous fistulasInsignificant and physiologicVery significant
Lateral venous anomalyVery commonNot found
Lymphatic malformationsPresentVery rare
Lymphatic vesiclesPresentNot found
Venous flaresPresentNot found
Limb affected
Limb enlargementUsually disproportionate, involving soft tissue and bone; macrodactyly, particularly of toes, is commonArm or leg length discrepancy
PrognosisUsually good; pulmonary embolism is encountered in about 10% of childrenMore problematic, particularly in those who develop heart failure resulting in cardiac enlargement and cutaneous ischemia, requiring limb amputation

By reviewing the three articles by Parkes Weber 1907, 1908, 1918 it is clear that he does not use a hyphen between Parkes and Weber, yet in most articles published on the subject the authors have added a hyphen (Parkes-Weber syndrome) just as they have added an accent é in Trénaunay's name. We have to believe that Parkes Weber and Trenaunay knew how to spell their own names and this should be respected.

Kasabach–Merritt Phenomenon

The term “Kasabach–Merritt syndrome” is frequently applied incorrectly to patients with extensive venous or lymphaticovenous malformations who develop a localized intravascular coagulopathy (chronic consumptive coagulopathy) in which the platelet count is minimally depressed, varying from 50,000 to 150,000/mm3. In contrast, with true Kasabach–Merritt phenomenon, thrombocytopenia is profound, varying from 3,000 to 60,000/mm3 with an average of less than 25,000/mm3 [Sarkar et al., 1997]. The distinction has important treatment implications. For example, heparinization might be warranted in consumptive coagulopathy in vascular malformations, particularly with thrombotic complications, but is contraindicated in Kasabach–Merritt thrombocytopenia found with specific vascular tumors: Kaposiform hemangioendothelioma (not found with AIDS) and tufted angioma. These are both platelet trapping vascular tumors, but Kasabach–Merritt thrombocytopenia is not found with infantile hemangiomas or with Klippel–Trenaunay syndrome. On the other hand, localized intravascular coagulopathy (chronic consumptive coagulopathy) can be found in Klippel–Trenaunay syndrome and other patients with extensive venous or lymphaticovenous malformations [Cohen, 2006].