Dataset Information

Fragile X and X-linked intellectual disability: four decades of discovery.

ABSTRACT: X-Linked intellectual disability (XLID) accounts for 5%-10% of intellectual disability in males. Over 150 syndromes, the most common of which is the fragile X syndrome, have been described. A large number of families with nonsyndromal XLID, 95 of which have been regionally mapped, have been described as well. Mutations in 102 X-linked genes have been associated with 81 of these XLID syndromes and with 35 of the regionally mapped families with nonsyndromal XLID. Identification of these genes has enabled considerable reclassification and better understanding of the biological basis of XLID. At the same time, it has improved the clinical diagnosis of XLID and allowed for carrier detection and prevention strategies through gamete donation, prenatal diagnosis, and genetic counseling. Progress in delineating XLID has far outpaced the efforts to understand the genetic basis for autosomal intellectual disability. In large measure, this has been because of the relative ease of identifying families with XLID and finding the responsible mutations, as well as the determined and interactive efforts of a small group of researchers worldwide.

SUBMITTER: Lubs HA

PROVIDER: S-EPMC3322227 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Fragile X and X-linked intellectual disability: four decades of discovery.

Lubs Herbert A HA Stevenson Roger E RE Schwartz Charles E CE

American journal of human genetics 20120401 4

X-Linked intellectual disability (XLID) accounts for 5%-10% of intellectual disability in males. Over 150 syndromes, the most common of which is the fragile X syndrome, have been described. A large number of families with nonsyndromal XLID, 95 of which have been regionally mapped, have been described as well. Mutations in 102 X-linked genes have been associated with 81 of these XLID syndromes and with 35 of the regionally mapped families with nonsyndromal XLID. Identification of these genes has ...[more]

PMID: 22482801

Similar Datasets

Project description:Mutations in more than 500 genes have been associated with intellectual disability (ID) and related disorders of cognitive function, such as autism and schizophrenia. Here we aimed to unravel the molecular epidemiology of non-specific ID in a genetic isolate using a combination of population and molecular genetic approaches. A large multigenerational pedigree was ascertained within a Dagestan Genetic Heritage research program in a genetic isolate of indigenous ethnics. Clinical characteristics of the affected members were based on combining diagnoses from regional psychiatric hospitals with our own clinical assessment, using a Russian translation of the structured psychiatric interviews, the Diagnostic Interview for Genetic Studies and the Family Interview for Genetic Studies, based on DSM-IV criteria. Weber/CHLC 9.0 STRs set was used for multipoint parametric linkage analyses (Simwalk2.91). Next, we checked CNVs and LOH (based on Affymetrix SNP 5.0 data) in the linked with ID genomic regions with the aim to identify candidate genes associated with mutations in linked regions. The number of statistically significant (p ? 0.05) suggestive linkage peaks with 1.3 < LOD < 3.0 we detected in a total of 10 genomic regions: 1q41, 2p25.3-p24.2, 3p13-p12.1, 4q13.3, 10p11, 11q23, 12q24.22-q24.31, 17q24.2-q25.1, 21q22.13 and 22q12.3-q13.1. Three significant linkage signals with LOD >3 were obtained at 2p25.3-p24.2 under the dominant model, with a peak at 21 cM flanked by loci D2S2976 and D2S2952; at 12q24.22-q24.31 under the recessive model, with a peak at -120 cM flanked by marker D12S2070 and D12S395 and at 22q12.3 under the dominant model, with a peak at 32 cM flanked by marker D22S683 and D22S445. After a set of genes had been designated as possible candidates in these specific chromosomal regions,we conducted an exploratory search for LOH and CNV based on microarray data to detect structural genomic variants within five ID-linked regions with LOD scores between 2.0 and 3.9. In these selected regions we obtained 173 ROH segments and 98 CN segments. Further analysis of region 2p25.3-p24.2 revealed deletions within genes encoding MYTL, SNTG2 and TPO among five of 21 affected cases at 2p25.3-p24.2. In the ID-linked region at 12q24.22-12q24.31 19 out of 21 ID cases carried segmental CNV and 20 of 21 them displayed ROH segments with mean size lengths for ID cases 2512 kb (500-6,472 kb) and for healthy control 682 kb (531-986 kb), including the genes MED13L, HRK, FBXW8, TESC, CDK2AP1 and SBNO1. Seven of 21 affected pedigree members displayed segmental deletions at 22q12.3 that includes the gene LARGE. Eight affected pedigree members carried ROH segments and 6 CN segments at 10p11.23-p11.21 containing the genes ZEB1, c10orf68 and EPC1. Our linkage and structural genomic variation analyses in a remote highland genetic isolate with aggregation of ID demonstrated that even highly isolated single kindred ID has oligo/polygenic pathogenesis. The results obtained implicate 10 genomic regions linked with ID that contain some of previously reported candidate genes, including HRK, FBXW8, TESC, CDK2AP1 and SBNO1 at 12q24 that were shown in recent studies as associated with brain measures derived from MRI scans.

Dataset Information

Fragile X and X-linked intellectual disability: four decades of discovery.

Publications

Fragile X and X-linked intellectual disability: four decades of discovery.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets