Which disorder's chromosome pattern is described as 47, XXY?

Appeared in: PGICH Noida NO-2025

Explanation

Klinefelter syndrome is a sex chromosome aneuploidy that affects males.
It is characterized by the presence of an extra X chromosome, leading to a total of 47 chromosomes.
The specific karyotype for this condition is 47,XXY.
This extra chromosome leads to features such as hypogonadism, infertility, and often a taller stature.

Option A: Cri-du-chat syndrome is caused by a structural abnormality, specifically a deletion on the short (p) arm of chromosome 5 (5p-), not an aneuploidy of the sex chromosomes.
Option C: Turner syndrome is a monosomy of the sex chromosomes, meaning one is missing. The karyotype is 45,X, affecting females.
Option D: Prader-Willi syndrome is a microdeletion syndrome, caused by the loss of function of genes on the paternal copy of chromosome 15.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Chromosomal Abnormalities and Karyotypes as background academic context rather than a clinical decision trigger.
Nurses play a key role in identifying potential signs of Klinefelter syndrome, which is often underdiagnosed until puberty or adulthood when issues with fertility arise.
Management involves testosterone replacement therapy to promote development of secondary male characteristics, improve mood and energy, and increase bone density.
Patients require lifelong monitoring for associated health risks, including type 2 diabetes, autoimmune disorders (like lupus), and an increased risk of breast cancer and extragonadal germ cell tumors.

How to Approach the Question

This is a factual recall question that tests your knowledge of specific genetic disorders and their corresponding karyotypes.
First, analyze the karyotype given in the question: 47, XXY.
Break down the karyotype: '47' indicates an extra chromosome (aneuploidy), and 'XXY' indicates the sex chromosomes consist of two X's and one Y.
Recall or look up the definitions of the syndromes listed in the options.
Match the 47,XXY pattern to the correct syndrome. Klinefelter syndrome is defined by this specific karyotype in males.
Eliminate the other options by recalling their chromosomal basis: Turner syndrome is 45,X; Cri-du-chat is a 5p deletion; and Prader-Willi is a 15q deletion.

Concept Tested & Keywords

QXvJBhxwnPQoojRJSdYoGz

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 814-816

E6 Pathology- ROBBINS & COTRAN PATHOLOGIC BASIS OF DISEASE 10TH Ed p. 177-179

E6 Obstetrics Williams p. 7-18

Practise the full PGICH Noida NO-2025

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