A First Cytogenetic Study of Down Syndrome in Albania

Down syndrome (DS) also known as trisomy 21 is a genetic complex disorder and the most common and best known autosomal chromosome abnormality in humans. Even though the majority of cases of DS can be identified based on clinical findings, cytogenetic analysis is essential to confirm the diagnosis and to provide information for genetic counseling. The present study is the first national consecutive series of Down Syndrome in Albanian population during the period 1984-2015. This study allowed the frequency of three basic cytogenetical types and the frequency of occurrence of the rarer karyotypes of Down syndrome to be estimated. Also the maternal age effect on the frequency of births of children with Down syndrome was evaluated. The frequency of occurrence of the different karyotypes was analyzed. The free trisomy 21 was the most common karyotype (nearly 91 % of all cases). The ratio of mosaic trisomy 21 was 2.1 %. The ratio of Robertsonian and reciprocal translocations were 5, 7 % and 0.2 %, respectively. The chromosomal abnormalities (CAs) in addition to trisomy 21 were present in 0, 8 % of all cases. Conclusions Knowledge of the cytogenetic types are essential and carried out greatly helped in the management of these children and for counseling the affected families.