Cytogenetic tests are advised for which of the following conditions?

DSSSB -28 August 2019 (Shift-2)

Pathology & Genetics (E5)

Easy

Appeared in: DSSSB -28 August 2019 (Shift-2)

Explanation

Cytogenetic tests, such as karyotyping and chromosomal microarray (CMA), are designed to detect abnormalities in chromosome structure and number.
Unexplained mental retardation, now termed Intellectual Disability (ID), is a primary and classic indication for cytogenetic analysis.
A significant portion of individuals with moderate to severe ID have an identifiable chromosomal cause, such as trisomies (e.g., Down syndrome), deletions, or duplications.
Guidelines from multiple medical bodies recommend CMA as a first-tier genetic test for patients with unexplained ID, global developmental delay (GDD), and/or autism spectrum disorder (ASD).

Option A: While genetic testing, specifically Chromosomal Microarray (CMA), is now recommended for individuals with Autism Spectrum Disorder (ASD), 'Mental retardation' (Intellectual Disability) is the more fundamental and historically established indication for a broad cytogenetic workup. There is significant overlap, as testing in ASD is often prompted by co-occurring intellectual disability or dysmorphic features.
Option B: Schizophrenia is a complex, polygenic psychiatric disorder. Its diagnosis is based on clinical evaluation of symptoms, not on cytogenetic tests. While research has identified genetic risk factors, these are not detectable by standard karyotyping or microarray for diagnostic purposes.
Option D: Mania is a state of elevated mood and energy, characteristic of bipolar disorder. Like schizophrenia, it is a psychiatric condition diagnosed clinically. Cytogenetic testing has no role in its routine diagnosis or management.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Indications for Cytogenetic Testing as background academic context rather than a clinical decision trigger.
Nurses are often the first to observe developmental delays or dysmorphic features in children, making their role in identifying potential candidates for genetic evaluation crucial.
A nurse's understanding of testing indications is vital for patient education, managing parental expectations, and facilitating referrals to genetic counselors and specialists.
It is important to use current and respectful terminology. 'Mental retardation' has been replaced by 'Intellectual Disability' (ID) to reduce stigma and provide a more accurate functional description.

How to Approach the Question

First, understand the question's core: It asks for the primary condition for which 'cytogenetic tests' are used.
Define 'cytogenetic tests' in your mind: These are tests for chromosomal abnormalities (e.g., wrong number, large deletions/additions).
Evaluate each option's connection to large-scale chromosomal errors:
Autism: Known to have a genetic component, and testing is increasingly common, making it a plausible distractor.
Schizophrenia/Mania: These are psychiatric diagnoses. While genetics play a role, they are not typically diagnosed via chromosome analysis.
Mental retardation (Intellectual Disability): This is a classic, textbook indication for investigating a potential chromosomal cause, as many genetic syndromes (like Down syndrome) present with ID.

Concept Tested & Keywords

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