Unusual Duplication in the Pericentromeric Region of Chromosome 9 in a Patient with Phenotypic Alterations

Author(s)

Malinverni, Andrea C. M. ; Colovati, Mileny E. ; Perez, Ana B. A. ; Caneloi, Thamy P. ; Oliveira, Jr., Helio R. ; Kosyakova, Nadezda ; Liehr, Thomas ; Hamid, Ahmed B. ; Melaragno, Maria I.

• Document type: Journal article
• Source: Cytogenetic and Genome Research; v. 150, n. 2, p. 100-105, 2016.
• Web of Science Citations: 0

Abstract

Several alterations involving the pericentromeric region of chromosome 9 are considered as normal population variants. These heterochromatic variants or heteromorphisms can include 9qh+, 9cen+, 9ph+, 9ph-, inv(9)(p11q13), and other patterns which can only be defined by FISH studies. However, some heteromorphisms have been found more frequently in patients with several clinical disorders. Here, we report on a patient with intellectual disability, language and neurodevelopmental delay, as well as facial dysmorphism and an unusual chromosome 9. While the banding karyotype was indicative of a simple pericentric inversion of one chromosome 9 {[}46, XX, inv(9)(p12q13)], array comparative genomic hybridization showed a 6-Mb duplication, including 22 genes: arr{[}hg19] 9p13.1p11.2(38,869,901-44,870,714) x3 dn. Molecular cytogenetics using a panel of probes specific for the pericentromeric region of chromosome 9 showed an unusual, rearranged chromosome 9, der(9)(pter -> p11.2:: q21.11 -> q12:: p11.2 -> p13.2:: q12 -> p11.2: : q21.11 -> qter), that has not been described before. The patient's phenotypic alterations are probably due to the de novo 6-Mb 9p duplication, although a review of similar cases showed some reports considering this duplication in the euchromatic region as a benign variant. Interestingly, this is the first report of a possible adverse inversion loop formation due to a known heteromorphic pericentric inversion present in the phenotypically normal father of the patient. (C) 2017 S. Karger AG, Basel (AU)

• FAPESP's process: 14/11572-8 - Chromosomal rearrangements and their relevance in the etiology of genetic disorders: cytogenomic and molecular investigation
• Grantee: Maria Isabel de Souza Aranha Melaragno
• Support Opportunities: Research Projects - Thematic Grants