Shunchang Sun1, Fuwei Luo, Zhiming Zhou, Weiqing Wu. 1. Department of Clinical Laboratory, Shenzhen Baoan Hospital, Southern Medical University, 118 Longjing Er Road, Baoan, Shenzhen, Guangdong 518101, China. bayyyz@yahoo.com.cn
Abstract
OBJECTIVE: To identify the underlying androgen receptor gene mutation in a Chinese patient with typical symptoms of complete androgen insensitivity syndrome. STUDY DESIGN: A Chinese female phenotype with 46, XY karyotype was diagnosed because of primary amenorrhea. Mutations were determined by polymerase chain reaction followed by DNA sequencing. RESULTS: DNA sequencing of the androgen receptor gene showed a G2439T transition causing E442X mutation in exon 1 in the patient with complete androgen insensitivity syndrome. The E442X mutation was a new de novo non-sense mutation in exon 1 of the androgen receptor gene. This non-sense mutation is located in the N-terminal transactivation domain and leads to a predicted truncated protein of 441 amino acids with loss of the end part of the N-terminal transactivation domain, and the DNA-binding and ligand-binding domain. CONCLUSION: This E442X non-sense point mutation has not been described previously in cases of androgen insensitivity syndrome, and could lead to the synthesis of a short truncated non-functional androgen receptor probably responsible for the phenotype of complete androgen insensitivity syndrome in the affected individual. Gonadectomy should be planned to eliminate the risk of gonadal malignancy.
OBJECTIVE: To identify the underlying androgen receptor gene mutation in a Chinese patient with typical symptoms of complete androgen insensitivity syndrome. STUDY DESIGN: A Chinese female phenotype with 46, XY karyotype was diagnosed because of primary amenorrhea. Mutations were determined by polymerase chain reaction followed by DNA sequencing. RESULTS: DNA sequencing of the androgen receptor gene showed a G2439T transition causing E442X mutation in exon 1 in the patient with complete androgen insensitivity syndrome. The E442X mutation was a new de novo non-sense mutation in exon 1 of the androgen receptor gene. This non-sense mutation is located in the N-terminal transactivation domain and leads to a predicted truncated protein of 441 amino acids with loss of the end part of the N-terminal transactivation domain, and the DNA-binding and ligand-binding domain. CONCLUSION: This E442X non-sense point mutation has not been described previously in cases of androgen insensitivity syndrome, and could lead to the synthesis of a short truncated non-functional androgen receptor probably responsible for the phenotype of complete androgen insensitivity syndrome in the affected individual. Gonadectomy should be planned to eliminate the risk of gonadal malignancy.