Androgenization in Klinefelter syndrome: Clinical spectrum from infancy through young adulthood
| Autor: | Jordan A Cohen, Jordan C. Best, Daniel E. Nassau, Alireza Alam, Ranjith Ramasamy, Daniel C. Gonzalez |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Adult
Male Secondary sex characteristic Urology 030232 urology & nephrology Physiology Young Adult 03 medical and health sciences Klinefelter Syndrome 0302 clinical medicine Hypergonadotropic hypogonadism 030225 pediatrics Cryptorchidism Testis medicine Humans Young adult Child Spermatogenesis Azoospermia business.industry Virilization Infant Newborn Infant medicine.disease Virilism Pubic hair medicine.anatomical_structure Gynecomastia Pediatrics Perinatology and Child Health Female medicine.symptom Klinefelter syndrome business |
| Zdroj: | Journal of Pediatric Urology. 17:346-352 |
| ISSN: | 1477-5131 |
| Popis: | Klinefelter syndrome (KS) is an uncommon chromosomal disorder in males that has a variable clinical appearance. Classic KS involves an extra X chromosome, (47, XXY), although other variations may exist, including a milder mosaic form as well as multiple extra sex chromosomes with more dramatic phenotypes. KS is underdiagnosed, especially pre-pubertally, owing to a paucity of concrete clinical signs; however, diagnostic rates increase during and after puberty, as the consequences of hypergonadotropic hypogonadism begin to manifest. Testicular failure causing decreased circulating testosterone (T) and germ cell depletion, a hallmark feature in KS, commonly begins shortly after the onset of puberty and leads to the most commonly recognized KS traits: small testes, azoospermia, gynecomastia, decreased facial and pubic hair. While many KS men maintain adequate T levels leading up to young adulthood, some may have lower T levels at an earlier age leading to varied levels of androgenization and clinical KS features. At certain critical time points, absent or decreased T may alter the development of normal male reproductive organs, external genitalia, development of secondary sexual characteristics and spermatogenesis. Testicular failure in utero may lead to ambiguous genitalia, cryptorchidism and/or hypospadias, all of which depend on fetal T production. In the neonatal period and childhood, decreased T levels during the mini-puberty of infancy may negatively impact germ cell differentiation and male neuropsychological development. Finally, decreased T during pubertal and young adulthood can lead to decreased virilization during puberty, eunuchoid skeleton and decreased spermatogenesis. Depending on the timing of the testicular failure, a reproductive window of sperm production may exist to achieve paternity for KS men. The presence or absence of clinical characteristics reflecting decreased androgenization provides an insight to the relative testicular function during these developmental time points for those with KS and contributes to variability within the syndrome. |
| Databáze: | OpenAIRE |
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