Partial 9P Monosomy and Partial 8Q Trisomy by Adjacent 1 Segregation of Balanced Paternal Translocation Revealed by Molecular Karyotyping

Abstract

ABSTRACTWe present here the details of a six-month male infant with multiple congenital anomalies and developmental delay with an apparently balanced karyotype - 46, XY, inv(9)(p11q13) - and revealed by oligo array CGH del(9)(p24.3p22.2) and dup(8) (q24.13q24.3). We used BlueGnome CytoChip oligo 2X105K microarray, v1.1, with 35kbp backbone resolution. Fluorescence in situ hybridization (FISH) with BAC clones was performed to confirm the array CGH results in the patient and his family. The proband's father and sister carried the same inversion in 9th chromosome. It was initially assumed that the patient's imbalances are de novo, but the subsequent fine analysis of the FISH results and the karyotype reexamination revealed that it comes to familial reciprocal translocation between the 8th chromosome and the inverted 9th chromosome. The patient's phenotype was a result of adjacent 1 segregation during the 1st meiotic division. The duplicated segment from 8th chromosome harbors 84 OMIM genes and the deleted region in 9th chromosome contains 40 OMIM genes. We discuss the role of the gene dosage change to find some genotype-phenotype correlations.