To determine the frequency of subtelomeric abnormalities in children with idiopathic mental retardation.

Background: Cross-sectional study was carried out to determine the frequency of subtelomeric abnormalities in children with idiopathic mental retardation (MR).

Methods: Multiplex ligation-dependant probe amplification technique was used to detect subtelomeric abnormalities.

Results: Out of 35 children, 21 (60%) were males. Family history of MR was present in 23%. Main clinical features included speech delay in all motor delay cases (83%) and non-specific dysmorphic features (77%).

Conclusions: Associated clinical features were more in children with intelligence quotient (IQ) < 50 (P < 0.05). Subtelomeric deletion (4q35) was observed in one child.