Please choose the correct answer Severity of symptoms of cys

Please choose the correct answer. Severity of symptoms of cystic fibrosis may vary from one patient to the next. This variation seen is representative of...

a. variable expressivity

b. incomplete penetrance

c. codominance

d. dominant alleles

e. none of the above

Solution

Choice a is correct.

Reason: The cystic fibrosis is an autosomal recessive genetic disorder. Patients with homozyous recessive genotype express all the features of this disease where as in heterozygous individuals, only partial expression of the symptoms of this disease are present. This is becuase the heterozygous individuals also carry a copy of healthy allele for this disease. Thus, whereas homozygous recessive individuals are exteremely suffered from this disease with high clinical relavance, the heterozygous individuals display only partial symptoms.

Thus, the severity of symptoms depends upon the nature of genetic profile of an individual with respect to the disease.