CFTR Genetic Test Analysis
Cystic fibrosis and cystic fibrosis related disorders are caused by mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene. It is located on the long arm of chromosome 7. One of the most related abnormality associated with CFTR gene mutation in male is congenital bilateral absence of vas deference (CBVD) causing azoospermia, absence of sperm. CFTR mutations are also observed in non CBVD infertile men. Some of the common mutations found in CFTR gene are F508del, R117H, W1282X, G542X, 5T/7T/97.
Cystic fibrosis and cystic fibrosis related disorders are caused by mutations in cystic fibrosis transmembrane conductance regulator (CFTR) gene. It is located on the long arm of chromosome 7. One of the most related abnormality associated with CFTR gene mutation in male is congenital bilateral absence of vas deference (CBVD) causing azoospermia, absence of sperm. CFTR mutations are also observed in non CBVD infertile men. Some of the common mutations found in CFTR gene are F508del, R117H, W1282X, G542X, 5T/7T/97.
Recently it was identified that reduced expression of CFTR in sperm cells can cause teratospermia, oligospermia, asthenospermia. Spermatogenesis is a complex process, in the seminiferous tubules under the influence of different hormones FSH, LH and testosterone the stem cells divide and undergo different functional and morphological changes to become spermatozoa. Sertoli cells play an important role in the development of germ cells. These Sertoli cells provide proteins and growth factors for germ cells which is regulated by FSH hormone. The cAMP/PKA pathway and down stream transcription factors are activated by FSH. It is observed that CFTR plays a major role in the entry of HCO3 into Sertoli cells which helps in the activation of cAMP pathway. In humans the CFTR is expressed in stage specific manner this proves the important role of CFTR in male spermatogenesis. Female reproductive tract contains sperm capacitation molecules.
Sperm capacitation is very important for fertilization of oocyte. The female reproductive tract contains high concentration of HCO3that helps in different sperm physiological process like calcium influx, activation of cAMP pathway etc. All these process completely affects sperm motility, capacitation etc and there by increasing the chances of male related infertility.
The underlying cause of female infertility caused by CFTR is unclear. Little evidence shows that CFTR gene abnormalities cause viscosity in the female cervix thereby creating a barrier for sperm movement. It was observed that cystic fibrosis also causes abnormalities in endocrine function. CF in females also has a major impact on the successful outcome of the pregnancy.
