Isodicentric Y Chromosome with Multiple Breakpoints in the Pseudoautosomal Region 1

• Published in: Cytogenetic and genome research p. 1
• Main Authors: Ogiwara, Yasuko, Kobori, Yoshitomo, Suzuki, Erina, Hattori, Atsushi, Tanase-Nakao, Kanako, Osaka, Akiyoshi, Iwahata, Toshiyuki, Okada, Hiroshi, Kuroki, Yoko, Fukami, Maki
• Format: Journal Article
• Language: English
• Published: Switzerland 29.07.2024
• Subjects: Isodicentric chromosome; PAR1; Spermatogenic failure; Chromothripsis; Sex chromosome
• ISSN: 1424-859X
• DOI: 10.1159/000540634

Isodicentric Y chromosomes are relatively common structural variants of the human genome. The underlying mechanism of isodicentric Y chromosomes with short arm breakpoints [idic(Yq)] remains to be clarified. We encountered a Japanese man with azoospermia and mild short stature. G-banding and array-based comparative genomic hybridization indicated that his karyotype was 45,X/46,X,idic(Y)(qter→p11.32::p11.32→qter) with a ∼1.8 Mb terminal deletion. Whole-genome sequencing suggested that the Y chromosome had four breakpoints in a ∼7 kb region of the pseudoautosomal region 1 (PAR1). This case was assumed to have an idic(Yq) resulting from multiple DNA double-strand breaks in PAR1. This rearrangement may have been facilitated by the PAR1-specific chromatin architecture. The clinical features of the patient can be ascribed to SHOX haploinsufficiency and the presence of a 45,X cell line, although copy-number gains of some Yq genes and the size reduction of PAR1 may also contribute to his spermatogenic failure.