The value of optical genomic mapping in a patient with azoospermia and a complex chromosomal rearrangement

Complex chromosomal rearrangements (CCRs) are frequently associated with infertility and have been described in the literature. Chromoanagenesis corresponds to a group of CCRs with a high number of chromosome breakpoints. These CCRs involving small structural variations can only be identified by using high-resolution genomic techniques.

Here, we report on a male with azoospermia and a balanced CCR characterized using optical genome mapping. Although the CCR was initially thought to involve four chromosomes, the use of optical genome mapping (OGM) identified 11 breakpoints and led to a final diagnosis of chromothripsis.

According to the literature, CCRs supposedly lead to recurrent pregnancy loss in females and infertility in male and, more generally, to meiosis arrest. Optical genome mapping or whole-genome sequencing might be of value for identifying CCRs in patients with azoospermia (avoiding unnecessary testicular sperm extraction) and characterizing the risk of transmission of the unbalanced chromosome to the offspring.