[Pathogenesis of androgen insensitivity syndrome].

Androgen plays an important role in male sexual differentiation and the defect of androgen action mainly due to androgen receptor abnormality causes androgen insensitivity syndrome (AIS). The number of the reports of AR gene mutations is AIS reaches more than 250, including structural mutations such as gene deletion and single base mutations. The intriguing characteristics of the single amino acid substitutions by single base mutations are that they tend to occur in restricted areas and on restricted bases, and that the same mutation sometimes shows phenotypic variation even among the family members. In addition, in some AIS cases, neither androgen binding abnormality nor AR gene mutation is detected. In these cases, other factors which take part in transcriptional activation by AR might be affected.