The Genetic Aspects of Infertility

In the past, the causes of infertility were unknown. This is due to the fact that symptoms are hardly ever detectable. Most infertile individuals do not experience any symptoms at all. The small percentage that does show symptoms is very likely to receive an incorrect diagnosis. This occurs because the symptoms are very common to other illnesses as well. Symptoms such as loss of strength, and fatigue are common to many different conditions (Nachtigall LB, et al., 1997).

This disease was believed to be predominant in females. This assumption is incorrect, since males show the highest percentage of infertility in comparison to females.

Due to the complexity of spermatogenesis, the process through which millions of sperm cells are produced, the probability of defective sperm is higher than that of an egg in the female reproductive cycle. For spermatogenesis to be successful it requires the presence of androgens, and a

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This elongation is responsible for spermatogenic defects as well as reduced sperm count.

Reproduction in female vertebrates requires hormonal regulation by the hypothalamic- pituitary-gonadal axis in order to coordinate germ cell development, reproductive organ function, and sexual behavior. Therefore, the highly polymorphic genetic variation of the human MUC1gene is responsible for the outcome of these pregnancies. Should further elongation of the CAG repeat occur in these future generations, there is an added risk of increased severity of male infertility, potentially an increased incidence of neurodegenerative disease (Dowsing AT, et al. This method is effective in most affected females (Lee SL, et al. The trinucleotide repeat loci (CAG) were amplified by PCR, and the exact number of CAG repeats was calculated by direct sequencing of the PCR fragments. The CAG repeat lengths of the androgen-receptor gene was assessed by means of a PCR with primers specific for the repeat segment. While a moderate expansion of the CAG repeat region has a modulating effect on androgen-receptor function, whereas any expansion beyond a threshold is likely to trigger separate processes. Seven out of nine women that showed no evidence of implantation, even after the correct procedure was followed, had smaller, lower MUC1 allele than the normal fertile females. After receiving GnRH for at least six months most patients regain normal serum gonadotropin and testosterone concentration.

The sons of these female carriers would have a 50% chance of being affected by the mutation, and therefore be infertile (Dowsing AT, et al. The LH-b promoter contains binding sites for the estrogen receptor, another important female hormone (Lee SL, et al. After sequencing, samples were decoded (Dowsing AT, et al. It is the first molecule that the embryo encounters on attachment, and thus he source of the problem.

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