Connexion

GENATLAS PHENOTYPE

last update : 18-06-2013

Symbol	DEL2Q37
Location	2q37.3
Name	chromosome 2q subtelomeric deletion syndrome
Other name(s)	brachydactyly-mental retardation syndrome Albright hereditary osteodystrophy-like syndrome del 2q37 syndrome
Corresponding gene	GPC1 , GPR35 , STK25 , KIF1A , HDAC4
Other symbol(s)	BDMR, AHO3, 2QDCR
Main clinical features	frontal bossing, depressed nasal bridge, thin, highly arched eyebrows, deep-set eyes, anteverted nares, and thin upper lip AHO-like brachymetaphalangism (55%) mental retardation mild to severe, autism, repetitive, hyperkinetic behaviours (35%), non-febrile seizures (35%), eczema (25%), heart abnormalities (20%), short stature, obesity, stocky build rarely : Wilms tumor and urogenital anomalies, situs abnormalities, holoprosencephaly
Genetic determination	chromosomal
Prevalence	more than 100 cases reported
Function/system disorder	multisystem/generalized
	mental retardation
Type	MCA/MR

Gene product

Name

contiguous gene syndrome; HDAC4 is a histone deacetylase that regulates genes important in bone, muscle, neurological, and cardiac development

Mechanism(s)

Chromosome rearrangement	Effect	Comments

deletion	haploinsufficiency	mainly de novo cytogenetically visible deletions or subtelomeric screening, size range from 1,5 Mb to >10,5 Mb
translocation	haploinsufficiency	unbalanced translocation with associated trisomy

Remark(s)

2q subtelomeric polymorphism was frequently observed; deletion or mutation of HDAC4 results in reduced expression of RAI1, which causes Smith-Magenis syndrome when haploinsufficient, providing a link to the overlapping findings in these disorders, PMID: 20691407,, PMID:23188045

Genotype/Phenotype correlations

haploinsufficiency of HDAC4 causes brachydactyly mental retardation syndrome, with brachydactyly type E, developmental delays, and behavioral problems, PMID: 20691407;; HDAC4 is not fully penetrant concerning BDE phenotype, PMID:23188045