G708E mutation in the androgen receptor results in complete loss of androgen function

Abstract

End-organ resistance to androgens, called androgen insensitivity syndrome (AIS), is a rare disorder. The most common cause of AIS is mutations(s) in the androgen receptor (AR) gene; however, a significant number of these mutations have not been functionally analyzed. In the present study, we analyzed a case of complete AIS for mutations in the AR gene. Sequencing of the entire coding region of the AR gene revealed a 2650G>A mutation (mRNA sequence reference) in exon 4 of the gene, resulting in replacement of glycine with glutamate at codon 708 in the ligand-binding domain of the AR protein. The mutation was absent in 200 normal male individuals analyzed to look at its occurrence in general population. In vitro androgen-binding and transactivation assays showed that the mutation resulted in approximately 65% loss of ligand binding and almost complete loss of transactivation function. Complete AIS in this individual was due to a G708E substitution in the AR protein.