SINGLE NUCLEOTIDE SUBSTITUTION OF THE ANDROGEN RECEPTOR GENE IN A CASE WITH RECEPTOR-POSITIVE ANDROGEN INSENSITIVITY SYNDROME (COMPLETE FORM)

Complete androgen insensitivity syndrome is caused by X chromosome lin ked disorder resulting tn a target organ insensitivity to androgen. Tw o variants have been described in this syndrome. In the first, the bin ding of [H-3] dihydrotestosterone (17beta-hydroxy-5alpha-androstan-3-o ne) to the androgen receptor is undetectable (receptor-negative), wher eas in the second variant normal levels of androgen receptor are detec table but the binding of [H-3] dihydrotesterone to the androgen recept or is significantly thermolabile under certain conditions (receptor-po sitive). In receptor-negative cases. genetic disorders of the androgen receptor gene have been demonstrated. On the other hand. the genetic disorder of androgen receptor in receptor-positive cases is little kno wn. In this study, the gene structure of androgen receptor in a recept or-positive case using a polymerase chain reaction technique is studie d in the fibroblasts cultured from genital skin. The results demonstra te that the substitution of nucleotide (guanine-->cytosine) in exon G of the androgen receptor causes the replacement of an amino acid in po sition 820 (glycine-->alanine) which occurs in the hormone-binding dom ain of the androgen receptor. The substitution of nucleotide may expla in the thermolability of the androgen receptor in a case with receptor -positive androgen insensitivity syndrome.