title: The clinical phenotype in institutionalised adult males with X-linked mental retardation (XLMR).
abstract: In an institutionalised population of 471 mentally retarded adult residents (436 males and 35 females), 22 males (i.e. 5 % of the male population) had XLMR, accounting for 36.1 % of the residents diagnosed with a monogenic disorder (n = 61). Fragile X syndrome (FRAXA) was diagnosed in 16 residents, X-linked mental retardation with marfanoid habitus (Lujan-Fryns syndrome) in 2, and non-specific X-linked mental retardation (MRX) in 4 males. The 4 MRX-patients included 3 male sibs of a family, carrying a mutation in the IL-1 receptor accessory protein-like gene, and one male patient member of the MRX-44 family (linkage with LOD-score of 2.90). In the group of 215 males with idiopathic mental retardation (MR), family histories and pedigree data were compatible with XLMR in 35 males (35/215 = 16.3 %) from 32 families. Of these 35 males, 5.7 % were microcephalic with dysmorphic features and 5.7 % macrocephalic; micro-orchidism and macro-orchidism were each found in 11.4 %. One macrocephalic male had also macro-orchidism and dysmorphic features. In this study, the diagnosis of XLMR could thus be proposed in 57 males i.e. 13.1 % of the total male population. The clinical phenotype, behavioural problems and follow-up data in these different subgroups of XLMR are presented.
authors.affiliation: Centre for Human Genetics, University of, Leuven, Belgium.
authors.forename: G J
authors.initials: GJ
authors.lastname: Van Buggenhout
authors.forename: J C
authors.initials: JC
authors.lastname: Trommelen
authors.forename: H G
authors.initials: HG
authors.lastname: Brunner
authors.forename: B C
authors.initials: BC
authors.lastname: Hamel
authors.forename: J
authors.initials: J
authors.lastname: Fryns
mesh_terms: D000328:Adult; D000013:Congenital Abnormalities / Q000235:genetics / Q000503:physiopathology / Q000523:psychology; D005260:Female; D005600:Fragile X Syndrome / Q000235:genetics; D006778:Hospitals, Psychiatric / Q000706:statistics & numerical data; D006801:Humans; D007326:Institutionalization / Q000706:statistics & numerical data; D008607:Intellectual Disability / Q000235:genetics* / Q000503:physiopathology / Q000523:psychology; D008297:Male; D009426:Netherlands; D010375:Pedigree; D010641:Phenotype; D013577:Syndrome; D014960:X Chromosome