Akademik Veri Yönetim Sistemi
JOURNAL OF ISTANBUL FACULTY OF MEDICINE-ISTANBUL TIP FAKULTESI DERGISI, cilt.85, ss.279-284, 2022 (ESCI)
Duplication of the short arm (p) of chromosome (Chr.) 9 is a frequently seen abnormality while duplication of both p and long arm (q) is a rare chromosomal rearrangement derived mostly from parental translocations or inversions. The unbalanced products of the translocations are mostly derived from the 2:2 segregation of adjacent 1division while the ones due the adjacent two patterns are rare. Here, a dysmorphic infant with a pure duplication of 9pter to 9q22.31 is reported due to the product of the adjacent-2 segregation of maternal reciprocal translocation between the 9q22.31 and 22p11.1. The affected infant had two normal and one derivative/dicentric Chr.9 (carrying the centromere regions of both Chr.9 and Chr.22) with one normal Chr.22. These results were confirmed by the fluorescence in situ hybridization technique. Array-comparative genomic hybridization confirmed the breakpoints precisely and revealed a 61.75 megabases duplication of Chr.9 consisting of many genes such as BICD2, NTRK2, HNRNPK, and SMARCA2, which are mostly related to developmental delay and growth retardation. Additionally, the infant had ear abnormalities, microcephaly, and extremity abnormalities, which were the other findings of trisomy 9. In sum, the case has presented as a rare example of adjacent 2 division of 2:2 segregation and a pure partial trisomy of 9pter to 9q22.31.