An Unusual Case of Double Aneuploidy of Down Syndrome Associated with Triple x Syndrome: 48;xxx;21

Down syndrome is the most common chromosomal abnormality in humans with an estimated incidence of one case in 770 live births. However; the occurrence of double aneuploidy involving autosome and or sex chromosome is a very rare phenomenon in lives born and the majority of reported cases are presented in form of spontaneous abortions. Here; we are reporting a case of a Rwandan patient with combination of trisomy 21 and triple X syndrome. The proband was 8-month-old female with typical features of Down syndrome. In additional to Down syndrome features; the child presented with minor features of triple X syndrome characterized by hypotonia and seizures