A novel insertion-induced frameshift mutation of the androgen receptor gene in a patient with primary amenorrhea☆

OBJECTIVE To report a novel single nucleotide insertion mutation, and present the clinical, genetic, biochemical findings in a patient with primary amenorrhea. METHODS Chromosomal analysis was performed by harvesting lymphocytes from peripheral blood sample. Hormonal analysis was performed from the serum. After genomic DNA extraction from peripheral blood leukocytes the coding regions and corresponding exon-intron boundaries of sex-determining region Y (SRY) gene and androgen receptor (AR) gene were amplified by PCR and subjected to direct sequencing. RESULTS In the patient with a karyotype 46,XX, we identified a novel single nucleotide insertion mutation of the nucleotide G at position 2369 (GenBank accession number HM010955), resulting in amino acid interchange cysteine to tryptophan at codon 669 in exon 4 [Cys669Trp] (GenBank Protein_id ADF47187). CONCLUSIONS We report a novel single nucleotide insertion mutation in exon 4 region of the AR gene. The nature of the mutation presented in the patient is in the ligand-binding domain (LBD) of the AR gene. This insertion mutation was predicted to produce frame shift mutation and resulted in truncated form of the AR protein, implicating it in the phenotype observed with primary amenorrhea.