Inv dup del(10q): identification by fluorescence in situ hybridization and array comparative genomic hybridization in a fetus with two concurrent chromosomal rearrangements

Abstract

Objective: To present molecular cytogenetic characterization of an inverted duplication with terminal deletion of 10q, or inv dup del(10q) in a fetus with two concurrent chromosomal rearrangements.

Materials, methods and results: A 39-year-old woman underwent amniocentesis at 20 weeks of gestation because of advanced maternal age. Amniocentesis revealed a der(10) with additional material at the end of the long arm of chromosome 10, a der(9) and a der(22). Parental karyotypes were normal. A de novo unbalanced complex chromosomal rearrangement (CCR) was diagnosed by conventional cytogenetics, but the breakpoints could not be defined. The pregnancy was subsequently terminated, and a malformed fetus was delivered with facial dysmorphism. Postnatal analysis of fetal tissues using spectral karyotyping, fluorescence in situ hybridization, multicolor banding, and array-comparative genomic hybridization identified an inv dup del(10q) with an inverted duplication of 10q25.1→q26.2 and a terminal deletion of 10q26.2→qter, and a balanced reciprocal translocation between chromosomes 9 and 22. Microsatellite analysis determined a paternal origin of the inv dup del(10q). The karyotype of the fetus was 46,XX,t(9;22)(p23;q13),der(10)del(10)(q26.2) dup(10)(q26.2q25.1)dn.

Conclusion: A de novo inv dup del(10q) can be associated with a concurrent de novo balanced reciprocal translocation and should be differentiated from an unbalanced CCR by molecular cytogenetic techniques.