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Disorders of Androgen Action

المؤلف:  Wass, J. A. H., Arlt, W., & Semple, R. K. (Eds.).

المصدر:  Oxford Textbook of Endocrinology and Diabetes

الجزء والصفحة:  3rd edition , p1182

2026-10-10

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In XY DSD, a disorder of the androgen receptor leads to a phenotype that can range from a man with infertility through to a range of abnormalities of the genitalia in the newborn boy (partial androgen insensitivity syndrome, PAIS) to completely female ex ternal genitalia (Complete Androgen Insensitivity Syndrome, CAIS). The exact prevalence of PAIS and CAIS are unknown and estimates vary widely. Older estimates give prevalence rates of CAIS in 46,XY individuals of approximately 1:20 000 to 1:64 000. Children with AIS should have normal testosterone and dihydro testosterone response to hCG stimulation and should have a normal urinary steroid profile. However, a number of children with a confirmed genetic diagnosis of AIS may have a poor response to hCG stimulation, and this may be related to associated abnormalities of the testes or the test itself. The AMH level should be normal; sometimes it has been shown to be somewhat high for age- matched standards. Similarly, LH levels may be high especially following LHRH stimulation. There are no Müllerian ducts. In the older infant, fixed treatment with testosterone may not be accompanied by changes in testosterone responsive effects, such as a fall in SHBG or change in the size of the phallus. Mutational analysis of the androgen receptor gene (also called AR) will provide confirmation of the diagnosis. Androgen binding studies may be helpful in directing mutational analysis, particularly in cases of PAIS. As the condition is inherited in an X- linked pattern, a consistent family history is very helpful. Furthermore, exploration of X- linked markers in affected and non- affected family members can indicate the likelihood of the condition. A number of cases of XY DSD are incorrectly labelled as ‘PAIS’ when no firm biochemical or genetic abnormalities are identified in gonadal function, androgen synthesis or androgen action. Strictly speaking, the term PAIS should be reserved for those children who have XY DSD and a genetic abnormality of the AR gene. The children without a gen etic abnormality may be better described as ‘XY DSD with a non- specific disorder of under- masculinization’.