Klinefelter syndrome: phenotype, testicular function and infertility treatment

Klinefelter syndrome (KS) is a sex chromosomal disorder affecting males, particularly phenotypic manifestations, endocrinology and testicular function. Most KS men exhibit some form of testicular and gonadal dysfunction, and usually present with non-obstructive azoospermia or severe oligozoospermia, severelyaffecting their reproductive capacity. This review focuses on the molecular mechanisms behind these impairments which are related to the supernumerary X-chromosome universal to KS males. It alsodescribes the varying phenotypes and explores semen quality and infertility in KS men, additionally revealing how factors such as age, genotype and hypogonadism influence these KS manifestations. Lastly, it explores common ART techniques used to overcome infertility in KS males including different sperm retrieval techniques and intra-cytoplasmic sperm injection, as well as the concern surrounding transmission of chromosomal abnormalities to subsequent offsprin