Question

Marfan syndrome, a human genetic disorder caused by a single gene, results in defective connective tissue. The symptoms of this disorder range from skeletal issues to problems with the nervous and cardiovascular systems. This is an example of

Question 17 2.1 pts Marfan syndrome, a human genetic disorder caused by a single gene, results in defective connective tissue. The symptoms of this disorder range from skeletal issues to problems with the nervous and cardiovascular systems. This is an example of pleiotropy polygenic inheritance epistasis codominance linkage Dados Next MacBook Pro

Answer 1

Answer :

PLEIOTROPY.

Discussion and explanation :

Pleiotropy is a phenomenon when one gene controls or effects many phenotypic characters.

When a single phenotype (skin colour) is controlled by multiple genes, this genetic phenomenon is termed as polygenic inheritance.

Epistasis is a phenomenon in which one gene (modifier gene) effects the expression of another unrelated gene or allele.

When two or more alleles of a single gene get expressed completely as in ABO blood groups, the phenomenon is termed as codominance.

Linkage is the phenomenon in which two closely located genes are inherited together during meiosis in gamete formation.

Marfan syndrome is an autosomal dominant connective tissue disorder due to mutation in Fibrillin gene on chromosome 15. This single gene mutation effects many systems as given below :

1) Skeletal changes - Tall stature, long fingers (arachnodactyly), chest deformity (such as pectus exacavatum).

2) Ocular changes - Dislocation of lens (ectopia lentis), risk of retinal detachment.

3) Cardiovascular changes - Dilated aorta, aortic regurgitation, mitral valve prolapse.

Thus, Marfan syndrome is example of pleiotropy.