The Turkish Journal of Pediatrics
2009 , Vol 51 , Num 5
Subtelomeric Rearrangements of Dysmorphic Children with Idiopathic Mental Retardation Reveal 8 Different Chromosomal Anomalies
1Division of Clinical Genetics, Department of Pediatrics, and Departments of 2Medical Biology and Genetics, and 3Child
Neurology, Akdeniz University Faculty of Medicine, Antalya, Turkey
Subtelomeric rearrangements are an important cause of both sporadic and
familial idiopathic mental retardation (MR) and/or congenital malformation
syndromes. We report on a cohort of 107 children with idiopathic MR and
normal karyotype 450–550 band level by GTG banding screened for subtelomeric
rearrangements by multiprobe fluorescence in situ hybridization (FISH). In
these cases, five patients had de novo deletions (1p deletion was found in
2 cases; 3q deletion, 9p and 9q deletions were found in 1 case each) and
four patients had unbalanced rearrangements [der(5)t(5;15)(pter;qter)pat in 2
patients who were siblings, rec(10)dup(10p)inv(10)(p13q26)mat in 1 patient
and der(18)t(18;22)(qter;qter) de novo in 1 patient].
Our study confirms that the subtelomeric rearrangements are a significant
cause of idiopathic MR with dysmorphic features.
Keywords :
mental retardation, fluorescence in situ hybridization, subtelomeric FISH