Androgen receptor gene mutations in 46,XY females with germ cell tumours.

Abstract

We present clinical findings and molecular characterization in two patients previously diagnosed as 46,XY female gonadal dysgenesis with germ cell tumour. Both patients showed a female general phenotype with unambiguously female external genitalia and primary amenorrhoea compatible with complete androgen insensitivity syndrome. The first patient, at the age of 31 years, developed a dysgerminoma measuring 8 x 13 x 10 cm in one abdominal testis. Genetic analysis revealed a single nucleotide substitution on exon 4 in the hormone-binding domain of the androgen receptor (AR) gene, resulting in a change of codon 681 GAG (glutamic acid) to AAG (lysine). The second patient, at the age of 17 years, developed a dysgerminoma measuring 12 x 10 x 7 cm in one abdominal testis and gonadoblastoma in the other testis. Genetic analysis showed a point mutation on exon 3 in the DNA-binding domain of the AR gene resulting in a change of codon 607 CGA (arginine) to CAA (glutamine). Arg607-Gln and Arg608-Lys point mutations in the DNA-binding domain of the AR gene have been associated with male breast cancer in partial androgen insensitivity syndrome. A codon 607 mutation in the DNA-binding domain of the AR gene in our patient 2 is associated with early development of germ cell tumour. We suggest regular molecular genetic analysis of the AR gene in 46,XY females with germ cell tumour and androgen insensitivity syndrome to detect differences in the specific regions of AR gene involved in early progression toward oncogenesis of the dysgenetic gonads.