t(6;8)(q21;q24.1),+21 in newborn with Down Syndrome having cardiac, pulmonary and thyroid anomalies- A first case report

Trisomy 21 characterizing Down syndrome has often been reported with underlying translocation involving additional chromosome 21, especially Robertsonian translocations with D and G group chromosomes or mosaicism. There are very few reports on additional chromosomal abnormalities like translocation between chromosomes other that chromosome 21 along with trisomy 21. To the best of our knowledge, we report the first case of translocation between chromosomes 6 and 8 t(6;8)(q21;q24.1) along with trisomy 21. Further the report highlights the association of pulmonary and thyroid anomalies in Down syndrome in addition to cardiac abnormalities which are well known. The report also reiterates the importance of karyotyping in Down syndrome as compared to targeted techniques like Fluorescence in situ hybridization (FISH). Even in the present case, FISH technique only reflected on the status of numerical change (trisomy 21) and not underlying structural chromosomal abnormalities.