CHROMOSOMAL ANALYSIS OF MENTALLY RETARDED CHILDREN WITH MICROCEPHALY

Abstract

Background: Mental retardation is a common condition with the incidence of 1- 3% of the entire population; about 25% - 50% of them are genetic causes. Chromosomal causes account for up to 28%. Microcephaly and mental retardation may occur together as a syndrome. Cytogenetic and molecular analysis has been approved to definitively diagnose those syndromes. This research is aimed to know the chromosomal characteristic of children with mental retardation and microcephaly. Method: This research is observational descriptive study with retrospective data taken start from 2007-2009. The data of head circumference and chromosome analysis from 39 children were processed. The data are then presented as a descriptive statistic after being analyzed using Microsoft Excel 2007. Results: Chromosomal analysis results shows 18 (46.15%) children with 46,XX karyotype, 11 (28.21%) children with 46, XY karyotype, 5 (12.82%) children with 47,XX+21 karyotype, and 4 (10.26%) children with 47,XY+21 karyotype. There is also one Robertsonian translocation with 46,XX,+21, t(14;21) karyotype. Conclusion: Normal karyotype (46,XX and 46,XY) were found in 29 (74.36%) children. Visible chromosomal abnormalities detected includes 9 cases of Down syndrome trisomy 21 and one case of Robertsonian translocation with t(14;21) karyotype. Keyword: Mental retardation, microcephaly, chromosomal analysis