Homozygosity mapping in a family with microcephaly, mental retardation, and short stature to a Cohen syndrome region on 8q21.3-8q22.1: redefining a clinical entity.

[cohen syndrome]

A syndrome of microcephaly , progressive postnatal growth deficiency , and mental retardation was observed in two brothers and their cousin from a multiply consanguineous kindred of Lebanese descent . Hypotonia , chorioretinal dystrophy , and myopia were also identified . The severity of the condition varied among the closely related patients . Because of absence of a distinctive facial appearance , the degree of mental retardation , and short stature , the initially considered clinical diagnosis of Cohen syndrome was withdrawn and a novel genetic entity was assumed . Homozygosity mapping in this family assigned the gene to a 26 .8 -cM region on the chromosome band 8 q 21 .3 -22 .1 , between the microsatellites at D 8 S 270 and D 8 S 514 . The maximum two -point LOD score was found for marker at D 8 S 267 (Zmax =3 .237 at Omax =0 .00 ). Intriguingly enough , the identified gene region overlaps the refined gene region for Cohen syndrome (COH 1 ) [Kolehmainen et al ., 1997 : Euro J Hum Genet 5 :206 -213 ]. This fact encourages the hypothesis that the described kindred segregates for a variant of Cohen syndrome and suggests a redefinition of its phenotype .

Diseases
Validation

Diseases presenting "short stature" symptom

22q11.2 deletion syndrome

achondroplasia

alpha-thalassemia

aromatase deficiency

child syndrome

classical phenylketonuria

coats disease

cohen syndrome

congenital adrenal hyperplasia

cowden syndrome

dentin dysplasia

dentinogenesis imperfecta

fabry disease

hirschsprung disease

holt-oram syndrome

kabuki syndrome

kallmann syndrome

kindler syndrome

monosomy 21

oculocutaneous albinism

oligodontia

omenn syndrome

proteus syndrome

werner syndrome

wolf-hirschhorn syndrome

zellweger syndrome

This symptom has already been validated