title: A genetic-diagnostic survey in an institutionalized population of 158 mentally retarded patients. The Viaene experience.
abstract: In this report we summarize the results of a genetic-diagnostic survey of an institutionalized population of 158 severely mentally retarded patients. The etiological study was based on a clinical genetic approach with special attention to dysmorphology and neurological findings. In 72 patients a constitutional cause of their mental impairment was found: a chromosomal abnormality in 21, a Mendelian disorder in 36 (autosomal recessive disorder: 23; autosomal dominant: 12; and X-linked recessive: 1), a MCA/MR syndrome in 9, and a CNS malformation in 6 patients. In 33 patients, a pre- or perinatal cause was found, and 20 patients presented a pre- or perinatal infection of the CNS. Finally, no etiological diagnosis was detected in 28 patients; 6 of them presented a hitherto unclassifiable type of familial mental retardation.
authors.affiliation: Centre for Human Genetics, University of Leuven, Belgium.
authors.forename: A M
authors.initials: AM
authors.lastname: Dereymaeker
authors.forename: J P
authors.initials: JP
authors.lastname: Fryns
authors.forename: J
authors.initials: J
authors.lastname: Haegeman
authors.forename: J
authors.initials: J
authors.lastname: Deroover
authors.forename: H
authors.initials: H
authors.lastname: Van den Berghe
mesh_terms: D000293:Adolescent; D000328:Adult; D001530:Belgium; D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D004314:Down Syndrome / Q000235:genetics; D005600:Fragile X Syndrome / Q000235:genetics; D005799:Genes, Dominant; D005808:Genes, Recessive; D006801:Humans; D007326:Institutionalization; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping