Mr. Swain is a 29 year old Caucasian male suffering from the genetic disease, Cystic Fibrosis. Recently checking into a fertility clinic due to numerous attempts to bear child with his healthy wife, he was unfortunately diagnosed as having a male infertility condition directly attributed to the genetic abnormalities of Cystic Fibrosis. Male and female infertility is defined by the World Health Organization as ‘the inability of a sexually active, non-contracepting couple to achieve pregnancy in one year’. According to the European Association of Urology, 25% of couples do not achieve pregnancy within the year, and half of that figure is directly due to numerous male infertility conditions. Partial or complete male infertility can be the result of urogenital abnormalities, infections of the male accessory glands, increased scrotal temperatures, genetic inconsistencies, and endocrine instability. In the case of our patient Mr. Swain, his infertility is one of the numerous pathological conditions caused by the Cystic Fibrosis Transmembrane Conductance Regulator, or CFTR, gene.
This autosomal recessive gene controls the CFTR protein that lines the membrane of the apical layer in epithelial tissue. Therefore, in a patient with two mutated copies of this gene, Cystic Fibrosis occurs, causing the body to produce a thick, sticky mucus that the body is unable to cleanse naturally. This leads to infection and affects the lungs, pancreas, and liver as well as other vital organ systems. One of these systems is the male reproductive organ, or more specifically, the Vas Deferens. The Vas Deferens is a male anatomical structure of two ducts that transport sperm from the testes to the ejaculatory ducts. Congenital Absence of the Vas Deferens or CAVD, is a condition in which these vital reproductive ducts fail to form prior to birth, and can either be bilateral or unilateral. Whilst this accounts for a meager 2% of infertile males without Cystic Fibrosis, a published paper in the Journal of Pediatrics states that CAVD is one of the most consistent manifestations of Cystic Fibrosis, affecting over 98% of individuals inflicted. This disease is not limited to CF positive males though, as men carrying only one copy of the mutated gene have a higher chance of developing a poorly formed Vas Deferens structure then men with the a normal pair of genes. In a study conducted by the Medical University of Bialystok which tested 420 cases of men with abnormal vas deferens, 19% were carriers of two mutations of the CFTR gene, 47% of a single allele mutation and 34% of no identified mutation. Obstructive azoospermia is the resulting condition of both Cystic Fibrosis and CAVD and is characterized by the post pubertal patient not having any measurable level of sperm in his seamen due to the damaged vas deferens.
These genetic diseases are all associated with the F508 deletion mutation, responsible for two thirds of Cystic Fibrosis cases. It is the main defect associated with Cystic Fibrosis and also one of the major mutations associated with Congenital Absence of the Vas Deferens. In Cystic Fibrosis inflicted males, a major mutated allele such as F508 is usually paired with a milder mutation of the CFTR gene that allows partial function of the CFTR protein. The result of these mutations is similar to what happens in the alveolar epithelia of the lungs in which the movement of water and salt into and out of cells is disrupted. This disturbance leads to the production of a large amount of thick mucus that blocks the developing vas deferens in the fetus and causes it to degenerate before the male grows into puberty.
The prognosis of male infertility directly due to the Cystic Fibrosis gene is generally the same throughout most published material on the subject matter. Because the Vas Deferens is the only damaged structures and spermatogenesis occurs as per normal, the possibility of procreation is still a highly viable option for a Cystic Fibrosis patient such as Mr. Swain. The majority of medical literature recommends a variety of different assisted reproductive technologies utilizing In Vitro fertilization technology such as Intracytoplasmic sperm injection. However, most medical specialists refer couples with Cystic Fibrosis to a genetics counselor for further evaluation, and this is the same approach Mr. Swain is now taking. This process is designed to ensure minimum risk with the child and to educate and advise the patients of the consequences if the genetic disease is passed on. Thankyou