Case – Severely oligozoospermic patient with both mosaic Klinefelter syndrome and a complete azoospermia factor c (AZFc) Y chromosome microdeletion

摘要

Klinefelter syndrome (KS) is the most prevalent sex chromosomedisorder in males and is the most common geneticcause of male infertility.1,2 First described in 1942 as anendocrine disorder characterized by high follicle-stimulatinghormone (FSH) levels, small firm testes, gynecomastia, andhypogonadism.3 The most common chromosomal aberrationof KS is 47,XXY, where an additional X chromosome ispresent. The pathogenesis of KS can be explained by nondisjunctionin either meiotic divisions during germ-celldevelopment, or in early embryonic mitotic cell divisions.4A subset of KS, mosaic KS (46,XY/47,XXY), occurs when theextra X chromosome is only present in a certain proportionof cells. Men with mosaic KS have a higher prognostic valueof spermatogenesis than men with non-mosaic KS.