Final answer:
The increasing number of mutations identified in the CFTR gene and their inclusion in current genetic tests demonstrate genetic heterogeneity, which is the presence of multiple mutations that can cause cystic fibrosis, an autosomal recessive disorder.option a is correct answer.
Step-by-step explanation:
The facts presented about cystic fibrosis testing and the discovery of a large number of mutations in the CFTR gene over the years reflect genetic heterogeneity. Genetic heterogeneity is the occurrence of the same disorder, or similar phenotypes, caused by mutations in different genes or by different mutations in the same gene. In the context of cystic fibrosis (CF), although the initial CF test was designed to detect just one mutation, researchers have identified over 1,600 different mutations that can lead to the disease.
Consequently, the current tests can now detect around 100 of these mutations to determine carrier status or disease presence.
Autosomal recessive disorders, like cystic fibrosis, require an individual to inherit two copies of the mutant gene to exhibit the disease. This is why parents who are carriers (having one normal CFTR allele and one mutated allele) can have children who are carriers or affected by CF. Hereditary diseases carrier diagnosis plays a critical role in genetic counseling, where individuals or couples can be informed about their carrier status, the risks of passing on genetic diseases to their offspring, and the implications of such genetic information.
Understanding genetic variance is crucial for effective genetic testing and counseling. Today, prospective parents have access to gene testing for a variety of inheritable conditions, which allows them to make informed reproductive choices and prepare for the potential healthcare needs of their children.