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Syndromic form of X‐linked mental retardation with marked hypotonia in early life, severe mental handicap, and difficult adult behavior maps to Xp22
Author(s) -
Turner Gillian,
Gedeon Agi,
Kerr Bronwyn,
Bennett Rachael,
Mulley John,
Partington Michael
Publication year - 2002
Publication title -
american journal of medical genetics part a
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.064
H-Index - 112
eISSN - 1552-4833
pISSN - 1552-4825
DOI - 10.1002/ajmg.a.10005
Subject(s) - hypotonia , intellectual disability , chin , medicine , genetics , psychology , pediatrics , psychiatry , anatomy , biology
Abstract An X‐linked recessive syndromic form of mental retardation is described in a family in which 10 males in four generations were affected. The main manifestations were severe to profound intellectual disability, muscular hypotonia in childhood, delayed walking, and difficult, aggressive behavior. There was a moderate reduction both in occipitofrontal circumference (OFC) and height and a similar facial appearance, triangular in shape with a high forehead, prominent ears, and a small pointed chin. Linkage analysis located the gene at Xp22 with maximum lod scores of 4.8 at θ = 0.0 for markers mapping between the closest recombination points at DXS7104 and DXS418 . The physical length of this region is ∼6 Mb. Mutations in the GRPR gene and M6b genes were excluded by sequence analysis. Nearby genes in which mutations are known to be associated with mental retardation (RPS6KA3, STK9, and VCXA, B and C), were excluded by position. © 2003 Wiley‐Liss, Inc.