Cryptic Rearrangements in Idiopathic Intellectual Disability Diagnosed by Molecular Cytogenetic Analysis

Autor: Bouhjar, Inesse Ben Abdallah, Khelifa, Hela Ben, Soyah, Najla, Zerrelli, Soumaya Mougou, Gribaa, Moez, Elghezal, Hatem, Saad, Ali, Retardation, Prf: Tunisian Network on Mental
Zdroj: International Journal of Human Genetics; September 2012, Vol. 12 Issue: 3 p157-171, 15p
Abstrakt: AbstractWith the development of molecular cytogenetic techniques, it is possible to identify cryptic rearrangements involving the end of chromosomes. Subtelomeric chromosomal rearrangements represent a significant cause of idiopathic intellectual disability accounting for 6-10% of moderate to severe cases and 0.5% in individuals with mild intellectual disability. We investigated 50 patients with severe intellectual disability combined with a dysmorphic features and normal 400-550 band karyotype for unbalanced subtelomeric rearrangements by using fluorescence in situ hybridization with probes mapping to forty one telomeric-specific regions. Nine positive cases (18%) were found. Six were de novo deletions (1p, 2q, 6p, 9q, 10q, 22q) and one wasis de novo duplication (10q) .Two unbalanced translocation (a der(3)t(3p; 2q) and a der(3)t(3p; Xq)) were inherited from the balanced mothers. Our study supportsed the hypothesis that subtelomeric rearrangements are a significant cause of idiopathic intellectual disability. The clinical features of patients with subtelomeric abnormalities and the candidate genes proposed inside each region will help to better delineate the phenotype-genotype correlation.
Databáze: Supplemental Index