[Genetic analysis and PGT-SR outcome of a male carrier of exceptional complex chromosome rearrangement].

ABSTRACT

OBJECTIVE: To investigate the clinical and genetic characteristics of a male carrier of exceptional complex chromosome rearrangement (CCR) and the outcome of preimplantation genetic testing for chromosomal structural rearrangement (PGT-SR). METHODS: Using the modified high resolution G banding technique and whole-genome low-coverage sequencing (WGLCS), we analyzed the cellular karyotype and molecular karyotype of a male carrier of CCR, performed an analysis of the single-sperm chromosome copy number and conducted PGT-SR for the patient by next-generation sequencing (NGS). In addition, we reviewed the literature on reported male carriers of CCRs and summarized their normal/balanced sperm ratios and PGT-SR outcomes. RESULTS: The karyotype of the patient was 46,XY,der(5)inv(5)(q14.3q23.2)t(5;14;11) (q23.2;q31.1;q21),der(11)t(5;14;11);der(14)t(5;14;11), with the translocation breakpoints located in the intergenic region. Single-sperm sequencing revealed 20.0%（7/35）of normal haploids in the male's spermatozoa， and the results PGT-SR showed a proportion of 25.0%（4/16）of normal/balanced embryos. After thawing and transferring of 2 euploid blastocysts, a healthy male infant was successfully delivered. CONCLUSION: The proportion of normal haploids in the spermatozoa of male CCR carriers may be higher than theoretically predicted, and PGT-SR can effectively improve the pregnancy outcome in male CCR carriers and provide valuable data for genetic counseling.