A medical disorder resulting from mutation in the DNA repair system is?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Pathology & Genetics

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2016

Explanation

Bloom syndrome is a classic example of a chromosome instability syndrome, which arises from defects in DNA repair.
It is caused by an autosomal recessive mutation in the BLM (RECQL3) gene.
This gene codes for a DNA helicase, an enzyme essential for DNA replication and repair.
The defect leads to a high rate of sister chromatid exchanges and chromosomal breaks, resulting in genomic instability.
This instability is responsible for the key clinical features, including growth deficiency, sun sensitivity, and a high risk of cancer.

Option B: Nephrotic syndrome is a kidney disorder involving damage to the glomeruli, leading to massive proteinuria. Its pathology is related to renal function, not a primary defect in the cellular DNA repair system.
Option C: 'Poly syndrome' is not a recognized medical term or a specific diagnosis. It is included as a distractor to test the candidate's knowledge of established medical syndromes.
Option D: Pierre-Robin syndrome (also called Pierre-Robin sequence) is a congenital condition characterized by a triad of craniofacial abnormalities. It is a structural, developmental defect that occurs during fetal development, not a disorder of DNA repair.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identification of genetic disorders caused by defects in the DNA repair system as background academic context rather than a clinical decision trigger.
Nurses play a vital role in educating patients and families with DNA repair disorders about lifelong preventative measures, such as rigorous sun protection and infection control.
Understanding the high risk of malignancy is crucial for patient advocacy, ensuring adherence to recommended cancer surveillance protocols.
Genetic counseling is a key component of care, helping families understand the inheritance pattern and risks for future pregnancies.

How to Approach the Question

First, analyze the question stem to identify the core concept being tested. The keywords are 'mutation' and 'DNA repair system'.
The question asks you to identify a disorder caused by a failure in the body's ability to repair its DNA.
Review each option and recall its underlying cause or primary characteristic.
Eliminate options that are clearly unrelated to genetic DNA repair mechanisms. For example, Nephrotic syndrome is a kidney disease, and Pierre-Robin syndrome is a congenital structural defect.
Identify the option that is a known genetic syndrome linked to chromosomal instability or a defect in a DNA repair gene.
Bloom syndrome is a classic example of a chromosome instability syndrome caused by a mutation in a DNA helicase gene, making it the correct choice.

Concept Tested & Keywords

Concept Tested: Identification of genetic disorders caused by defects in the DNA repair system.
Stem keywords: medical disorder, mutation, DNA repair system
Lead-in keywords: is
Negative lead-in flag: false

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