Euchromatic variants of 8q21.2 in twins

Abstract

Objective: Euchromatic variants (EVs) of 8q21.2 are extremely rare chromosomal abnormalities. So, far there have only been two reports on EVs of 8q21.2. Here, we report an 8q21.2 EV detected in cultured amniotic-fluid cells of twins. It was later found to be inherited from the mother, who did not present with abnormal phenotypes. Case Report: A pregnant woman underwent amniocentesis at 16 weeks of gestation because of advanced maternal age. This pregnancy was monozygotic twins conceived naturally. A cytogenetic analysis of cultured amniocytes revealed 46,XY,?dup(8)(q21.2). Chromosomal microarray revealed no abnormalities. C-banding and fluorescent in situ hybridization using chromosome 8 painting probe suggested euchromatic nature of the extra chromosomal band. Karyotyping of the parents showed that the EV was inherited from the mother. Conclusion: Many, but not all, EVs are clinically innocuous. This is the first case of 8q21.2 EV reported in the ethnic Han. More cases are needed to clarify whether 8q21.2 duplication as a bona fide EV.

Keywords

• amniocentesis
• euchromatic variants
• cytogenetic analysis
• 8q21.2