Clinical and karyotypic aspects of Down's syndrome in Sudanese patients

Abstract

Introduction Trisomy 21 or Down syndrome is the most common type of autosomal chromosome abnormality it has three chromosomal patterns the free copies of chromosome 21, translocation and mosaics. The aims of this study were to evaluate the clinical and the karyotypic pattern of Sudanese Down's syndrome patients and to compare the data with what have been reported before.

Material and Methods A total of 230 patients referred during 2009 and 2013 for confirmation of Down syndrome by cytogenetic analysis at the Cytogenetic Unit at Al Neelian Medical Research Center, faculty of medicine, Al Neelian University, Sudan.

Cytogenetic analyses performed in peripheral blood samples that cultured in RPMI 1640 medium for three days, the clonality criteria and the karyotypic descriptions were according to the ISCN 2009 recommendations.

Result Out of the 230 cases of Down's syndrome male to female ratio was found to be (1.2:1) in the referred cases, free trisomy 21 was present in 221cases (96. 4%), 6 patients had translocation (2.6%) and three cases were mosaics (1.3%) The median maternal age of the Sudanese mothers at the birth of the affected child was 35.9 years the average age at presentation was 15.6 months (range 1 days to13years), 43.9% of the cases had congenital heart disease.

Conclusion the identification of specific types of chromosomal abnormalities in Down's syndrome patients showed that regular trisomy 21 is more common than translocation and Mosaics which is important to assists in patient management and family counseling.