Gernot H. G. Sinnecker

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Androgen insensitivity syndromes (AIS) are due to end-organ resistance to androgenic steroids in males leading to defective virilization of the external genitalia. The phenotype encompasses a wide array of genital ambiguity and may range from completely female to undervirilized but unequivocally male with infertility. This disorder is caused by mutations of(More)
Abnormal human spermatogenesis is caused by a variety of genetic and acquired conditions. Because spermatogenesis is dependent on androgens, some males may have a minimal form of androgen insensitivity that does not inhibit virilization but impairs fertility. This has lead us to investigate the possibility of abnormalities in the androgen receptor (AR) gene(More)
Conversion of testosterone (T) to dihydrotestosterone (DHT) in genital tissue is catalysed by the enzyme 5 alpha-reductase 2, which is encoded by the SRD5A2 gene. The potent androgen DHT is required for full masculinization of the external genitalia. Mutations of the SRD5A2 gene inhibit enzyme activity, diminish DHT formation, and hence cause(More)
Recent studies indicate that mutations in the androgen receptor gene are associated with androgen insensitivity syndromes, a heterogeneous group of related disorders involving defective sexual differentiation in karyotypic males. In this report, we address the possibility of rapid mutational analysis of the androgen receptor gene for initial diagnosis,(More)
The medical management of differences of sex development (DSD)/intersex in early childhood has been criticized by patients’ advocates as well as bioethicists from an ethical point of view. Some call for a moratorium of any feminizing or masculinizing operations before the age of consent except for medical emergencies. No exhaustive ethical guidelines have(More)
OBJECTIVE The objective of this study was to assess somatic and inherited androgen receptor gene mutations in families with only one affected individual. METHODS Molecular genetic analysis of the androgen receptor gene in DNA derived from blood leukocytes from 30 families with single-strand conformation analysis, direct sequencing, and restriction(More)
Premature stop codons of the human androgen receptor (AR) gene are usually associated with a complete androgen insensitivity syndrome. We, however, identified an adult patient with a 46,XY karyotype carrying a premature stop codon in exon 1 of the AR gene presenting with signs of partial virilization: pubic hair Tanner stage 4 and clitoral enlargement. No(More)
Molecular causes of phenotypic diversity in androgen insensitivity syndrome, occurring even in the same family, have rarely been identified. We report on a family with four affected individuals, three brothers (B1-3) and their uncle, displaying strikingly different external genitalia: B1, ambiguous; B2, severe micropenis; B3, slight micropenis; and uncle,(More)
BACKGROUND Defective male sex differentiation in patients with hypoplasia of Leydig cells (LCH) is caused by deficient LH receptor signal transduction. To further investigate the variety of LH receptor gene mutations present in LCH patients and their influence on the phenotype, we examined 10 nonrelated patients with the clinical presentation of LCH. (More)
Point mutations in the androgen receptor gene cause androgen insensitivity syndromes, clinically characterized by masculinization defects in karyotypic males due to endorgan resistance to androgenic steroids. Characterization of these mutations with single strand conformation polymorphism analysis utilizing radioactive PCR can serve as a diagnostic tool for(More)