Subtelomeric study of 132 patients with mental retardation reveals 9 chromosomal anomalies and contributes to the delineation of submicroscopic deletions of 1pter, 2qter, 4pter, 5qter and 9qter

• Published in: BMC medical genetics Vol. 6; no. 1; p. 21
• Main Authors: Sogaard, Marie, Tümer, Zeynep, Hjalgrim, Helle, Hahnemann, Johanne, Friis, Birgitte, Ledaal, Paal, Pedersen, Vibeke Faurholt, Baekgaard, Peter, Tommerup, Niels, Cingöz, Sultan, Duno, Morten, Brondum-Nielsen, Karen
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 17.05.2005; BioMed Central; BMC
• Subjects: Abnormalities, Multiple - genetics; Adolescent; Adult; Bone Diseases, Developmental - genetics; Child; Child, Preschool; Chromosome Aberrations; Chromosome Deletion; Chromosome Painting - methods; Chromosomes, Human, Pair 2 - genetics; Chromosomes, Human, Pair 22 - genetics; Craniofacial Abnormalities - genetics; Female; Growth Disorders - genetics; Humans; In Situ Hybridization, Fluorescence - methods; Intellectual Disability - genetics; Karyotyping; Male; Syndrome; Telomere - genetics; Translocation, Genetic - genetics
• ISSN: 1471-2350; 1471-2350
• DOI: 10.1186/1471-2350-6-21

Cryptic chromosome imbalances are increasingly acknowledged as a cause for mental retardation and learning disability. New phenotypes associated with specific rearrangements are also being recognized. Techniques for screening for subtelomeric rearrangements are commercially available, allowing the implementation in a diagnostic service laboratory. We report the diagnostic yield in a series of 132 subjects with mental retardation, and the associated clinical phenotypes. We applied commercially available subtelomeric fluorescence in situ hybridization (FISH). All patients referred for subtelomeric screening in a 5-year period were reviewed and abnormal cases were further characterized clinically and if possible molecularly. We identified nine chromosomal rearrangements (two of which were in sisters) corresponding to a diagnostic yield of approx. 7%. All had dysmorphic features. Five had imbalances leading to recognizable phenotypes. Subtelomeric screening is a useful adjunct to conventional cytogenetic analyses, and should be considered in mentally retarded subjects with dysmorphic features and unknown cause.