A 38-year-old woman shows evidence of early cataracts, hair loss, atrophy of skin, osteoporosis, and accelerated atherosclerosis. This patient has most likely inherited mutations in both alleles of a gene that encodes which of the following types of intracellular proteins?

Helicase. Werner syndrome is a rare autosomal recessive disease characterized by early cataracts, hair loss, atrophy of the skin, osteoporosis, and accelerated atherosclerosis. Affected persons are also at risk for development of a variety of cancers. Unlike Hutchinson-Gilford progeria, patients with Werner syndrome typically die in the fifth decade from either cancer or cardiovascular disease. Werner syndrome is caused by mutations in the WRN gene, which encodes a protein with multiple DNA-dependent enzymatic functions, including proteins with ATPase, helicase, and exonuclease activity. Hutchinson-Gilford progeria is caused by mutations in the human lamin A gene, which encodes an intermediate filament protein that form a fibrous meshwork beneath the nuclear envelope. Mutations in the other choices are not associated with Werner syndrome.Diagnosis: Werner syndrome