Regarding Werner syndrome
Assertion: characterized by premature aging
Reason: Defect in enzyme DNA helicase
|A||Both Assertion and Reason are true, and Reason is the correct explanation for Assertion|
|B||Both Assertion and Reason are true but Reason is not the correct explanation for Assertion|
|C||Assertion is true but Reason is false|
|D||Reason is true but Assertion is false|
(Ref: Robbins Basic Pathology (8th ed.). Saunders Elsevier. Ch 1 Cell Injury, Cell Death, and Adaptations)
a. Werner syndrome is a very rare, autosomal recessive disorder characterized by the appearance of premature aging.
b. The WRN gene associated with Werner Syndrome lies on chromosome 8 in humans and it is the only gene known to be associated with Werner syndrome.
c. The disease is caused by a mutation in the WRN gene (or RECQL2) which codes a DNA helicase that functions 3' 5' as well as base exertion properties that also function in the same direction.
d. Increased telomere attrition and genomic instability have been observed in Werner syndrome, and rapid telomere decay is thought to play a causal role in the clinical and pathological manifestations of the disease.