Which of the following disease is NOT caused by chromosomal abnormalities in babies?

Appeared in: CIP Ranchi 2023

Explanation

Haemophilia is a single-gene, X-linked recessive disorder, not a chromosomal abnormality.
It is caused by a mutation in the gene responsible for producing clotting factor VIII (Haemophilia A) or factor IX (Haemophilia B).
In individuals with haemophilia, the number and overall structure of the chromosomes are normal.
The inheritance pattern follows Mendelian genetics, where the mutated gene is passed down from parent to child.

Option A: Turner's syndrome is a chromosomal abnormality. It is caused by the complete or partial absence of one of the two X chromosomes in females (karyotype 45,XO).
Option B: Down syndrome is a classic example of a chromosomal abnormality. It is caused by the presence of a third copy of chromosome 21 (Trisomy 21).
Option C: Klinefelter syndrome is a chromosomal abnormality affecting males. It is caused by the presence of an extra X chromosome (karyotype 47,XXY).

Clinical Relevance

Nursing practice connection: Knowing Differentiation between chromosomal abnormalities and single-gene (Mendelian) disorders helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
Nurses play a crucial role in genetic counseling, helping families understand the diagnosis, inheritance patterns, and implications of genetic disorders.
A clear understanding of the difference between chromosomal and single-gene disorders is essential for providing accurate patient education and support.
For chromosomal disorders, prenatal screening is often focused on maternal age and karyotyping, while for single-gene disorders like haemophilia, family history and specific gene testing are more relevant.

How to Approach the Question

First, identify the core of the question. It asks for the condition that is NOT a 'chromosomal abnormality'. This means you are looking for the outlier.
Define 'chromosomal abnormality' for yourself: a problem with the number (e.g., extra or missing) or large-scale structure of chromosomes.
Review each option against this definition.
Recall that Down syndrome involves an extra chromosome 21 (Trisomy 21). This is a chromosomal abnormality.
Recall that Turner's syndrome involves a missing X chromosome in females (XO). This is a chromosomal abnormality.
Recall that Klinefelter syndrome involves an extra X chromosome in males (XXY). This is a chromosomal abnormality.

Concept Tested & Keywords

Concept Tested: Differentiation between chromosomal abnormalities and single-gene (Mendelian) disorders.
Stem keywords: disease, chromosomal abnormalities, babies
Lead-in keywords: NOT
Negative lead-in flag: Question asks for the exception (NOT caused by...)

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E6 Parks TextBook of Preventive & Social Medicine part 2 — Subpart B (pp 233-449 of 464) p. 139-141

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E6 Text Book Of Pediatric Nursing 3rd Panchali Pal — Part 3 (pp 477-702 of 713) p. 94-96

Practise the full CIP Ranchi 2023

Attempt every question from this paper in a timed mock, then review the full solution for each one.