Cytogenetic diagnosis — which conditions can be detected by karyotyping as an unbalanced chromosomal complement?

Introduction / Context:
Karyotyping visualizes whole chromosomes to detect numerical abnormalities and large structural rearrangements. It remains a cornerstone for diagnosing aneuploidies and sex chromosome disorders.

Given Data / Assumptions:

• We are asked about conditions resulting from unbalanced complements.
• Examples include autosomal trisomy and sex chromosome aneuploidies.
• Karyotyping’s resolution is on the order of several megabases, not tiny microdeletions.

Concept / Approach:

Down’s (47, +21), Turner’s (45, X), and Klinefelter’s (47, XXY) are classic diagnoses by karyotype, clearly showing gains or losses of whole chromosomes or sex chromosomal complements.

Step-by-Step Solution:

Verification / Alternative check:

Clinical cytogenetics routinely confirms these diagnoses with karyogram analysis; additional techniques (FISH, microarrays) complement but are not required for whole-chromosome changes.

Why Other Options Are Wrong:

“Only microdeletions below 100 kb” are generally below karyotype resolution and require higher-resolution methods.

Common Pitfalls:

Confusing karyotyping’s strengths (aneuploidy) with its limitations (small CNVs).

Final Answer:

All of these