Endocrine Abstracts

Background: Klinefelter syndrome (KS) is the most frequent genetic cause of male infertility. Individuals share the endocrine hallmark of hypergonadotropic hypogonadism, displaying high gonadotropin levels due to deficient testicular function. A single-nucleotide polymorphism (SNP) located within the FSHB promoter region (−211G>T, rs10835638) was recently shown to be associated with reduced serum FSH levels and other reproductive parameters in men. The objec...

Background: Recently, a single nucleotide polymorphism (SNP) in the FSHB promoter (−211G>T, rs10835638) was found to be associated with lower serum FSH levels and oligozoospermia in males. In contrast, a SNP in the FSH-receptor gene (FSHR, 2039A>G, rs6166) was previously shown to be associated with FSH levels in women only.Subjects and methods: One thousand two hundred and thirteen male partners in infertile couples without known c...

Objectives: Male pseudohermaphroditism, or Leydig cell hypoplasia (LCH), is an autosomal recessive disorder in individuals with a 46, XY karyotype, characterized by a predominantly female phenotype despite the presence of testicular structures. It is caused by mutations in the luteinizing hormone/chorionic gonadotropin receptor gene (LHCGR), which impair either LH/CG binding or signal transduction. However, molecular analysis has revealed that the LHCGR is apparently normal in...

Male sexual development and masculinization are triggered by two hormones, CG and LH. While CG, produced by the trophoblasts during pregnancy, is essential for normal development of male secondary sex organs, pituitary LH is indispensable for virilization and initiation and maintenance of spermatogenesis. Both hormones exert their action via the LH receptor (LHR) expressed in the Leydig cells by stimulating testosterone biosynthesis. This two hormone/one receptor system is exc...

Background: The rare 46, XX-male syndrome has to be distinguished from more frequent forms of hypogonadism, especially the Klinefelter syndrome (47, XXY). We report 11 cases of SRY-positive XX-males in comparison to 101 age-matched Klinefelter patients and 78 age-matched normal men in a case-control study.Methods: The comparison included results from the physical examination, endocrinological data, semen analysis, cytogenetic and molecular genetic findin...

Intratesticular testosterone levels in Klinefelter syndrome (KS) are comparable to controls and Leydig cell function was proven to be normal at least in vitro, testicular vascularization changes came into focus as a potential factor contributing to hypogonadism. We performed enhanced ultrasound based analysis of the testicular blood support in our 41,XXY* mice. Adult male 41,XXY* (n=5) and control mice (n=6) underwent ultrasound...