Subtelomeric rearrangements in cryptogenic mental retardation

• Published in: Anales de pediatría (Barcelona, Spain : 2003) Vol. 75; no. 6; pp. 365 - 371
• Main Authors: Verdú Pérez, A, García Murillo, P L, García Campos, O, López Grondona, F, Arriola Pereda, G, Alcaraz Rousselet, M A, Vicente Lago, Y, Suela, J
• Format: Journal Article
• Language: Spanish
• Published: Spain 01.12.2011
• Subjects: Adolescent; Child; Child, Preschool; Female; Humans; Intellectual Disability - genetics; Male; Psychomotor Disorders - genetics; Telomere - genetics
• ISSN: 1695-9531
• DOI: 10.1016/j.anpedi.2011.06.002

Mental retardation affects 3% of the population, the origin of which cannot be established in 50% of cases. Subtelomeric rearrangements, not detected by routine cytogenetic studies, might explain some cases of unknown cause. A study was conducted on 200 subjects with unexplained mental retardations using multiplex ligation dependent probe amplification (MLPA). Abnormal findings were confirmed by fluorescent in situ hybridization (FISH) and/or comparative genomic hybridization technology (CGH-array). A subtelomeric aberration was identified in 9 patients. Eight were «de novo»; one was inherited from a phenotypically normal parent. There was a statistically significant association with the presence of more than one dysmorphic feature or with intrauterine growth retardation, but not with the severity of retardation or epilepsy. Subtelomeric rearrangements explained 4.5% of cases of mental retardation in our series. The presence of more than one dysmorphic feature or intrauterine uterine growth retardation increases the probability of this type of chromosomal aberration.