[A case of male infertility with a chromosomal abnormality of 45, X/46, X + mar].

A 28-year-old man visited our hospital with a complaint of male infertility. His development was normal with body size of 169.5 cm in height and muscular type. His beard and axillary and pubic hairs were male type. The penis and scrotum were also normal, but testes were small (8 ml, bilateral). Semen analysis revealed azoospermia. Serum luteinizing hormone (LH) and testosterone levels are within normal range but follicle stimulating hormone (FSH) was moderately elevated. Testicular biopsy specimen showed severely hyalinized seminiferous tubuli, incarceration of basement membrane and hyperplasia of Leydig cells. Johnsen's score count was two. Chromosomal analysis revealed a mosaic type of 45, X/46, X + mar. We tried to confirm the existence of sex-determining region of the Y chromosome (SRY) by the DNA analysis. It was shown that SRY on genomic DNA fragment. This marker chromosome may be translocated to a fragment of the short arm of Y chromosome.