A unique case of a discontinuous duplication 3q26.1-3q28 resulting from a segregation error of a maternal complex chromosomal rearrangement involving an insertion and an inversion

Abstract

Until now, few cases of partial trisomy of 3q due to segregation error of parental balanced translocation and segregation of a duplicated deficient product resulting from parental pericentric inversion have been reported so far. Only five cases of chromosomal insertion malsegregation involving 3q region are available yet, thus making it relatively rare. In this case report, we are presenting a unique case of discontinuous partial trisomy of 3q26.1-q28 region which resulted from a segregation error of two insertions involving 3q26.1 to 3q27.3 and 3q28 regions with ~21Mb and ~2Mb sizes, respectively. The maternally inherited insertion was cytogenetically characterized as der(8)(8pter→8p22::3q26→3q27.3::3q28→3q28::8p22→8qter) and the patient's major clinical features involved Dandy Walker malformation, sub-aortic ventricular septal defect, upslanting palpebral fissures, clinodactyly, hirsutism, and prominent forehead. Besides, a review of the literature involving cases with similar chromosomal imbalances and cases with "3q-duplication syndrome" is also provided.

Keywords: 3q-duplication syndrome; BAC; DD; DWM; Dandy Walker malformation; FISH; ID; MCB; Molecular cytogenetics; OFC; P; VSD; array comparative genomic hybridization; array-CGH; bacterial artificial chromosomes; developmental delay; fluorescence in situ hybridization; intellectual disability; multicolor banding technique; occipitofrontal circumference; percentile; subcenM-FISH; subcentromere-specific multicolor FISH; ventricular septal defect.