Hurtnup's disease is caused by point mutation of only one gene. This results in abnormal absorption of tryptophane in the intestine as well as its abnormal reabsorption in renal tubules. This causes synchronous disorders in digestive and urinary excretion systems. What genetic phenomenon is observed in this case?

Answer options

1. Semidominance
2. Codominance
3. Complementary interaction
4. Pleiotropy
5. Polymery

Explanation

Pleiotropy occurs when one gene influences two or more seemingly unrelated phenotypic traits. Thus, one gene defect contributes to multiple phenotypic effects. Marfan syndrome/Hartnup is a genetic disorder of the connective tissue and this defect is causing all the above phenotypic disorders.