Molecular mechanism of androgen receptor mutation in multigenerational mild androgen insensitivity syndrome.

Objective: Androgen insensitivity syndrome (AIS) due to androgen receptor (AR) mutations creates a spectrum of clinical presentations based on residual AR function with the mildest impairment creating mild AIS (MAIS) whose undefined molecular mechanism and subtle clinical features leave it less understood and underdiagnosed.

Design: In silico modeling and in vitro androgen bioassay of the mutated AR are used to identify its structural and physiological mechanism. Clinical features and responses to high-dose testosterone treatment of three cases of MAIS across a six-generation family pedigree are described.