Definition

Karyotype analysis performed by stimulating peripheral blood lymphocytes with phytohemagglutinin and culturing them is the standard method for constitutional cytogenetic evaluation. It is used in the assessment of developmental delay, congenital anomalies, ambiguous genitalia and infertility, and in confirming known syndromes such as Turner, Klinefelter and Down syndrome.

Method

Cell culture

Accepted sample types

Peripheral blood (heparinized)

Inheritance

Reflects the germline (constitutional) chromosome structure; detects hereditary or de novo structural changes such as numerical aneuploidy, translocation and inversion.

Related Tests

Inheritance Patterns

Describes how a genetic condition is passed on within a family. There are five main patterns

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Carrier (Heterozygous / Homozygous)

Why it matters: In autosomal recessive inheritance, when each parent is a carrier (while both appear healthy), the chance of their child being born with the disease is 25% in each

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VUS (Variant of Uncertain Significance)

This is the situation where the test has detected a change in the DNA, but the role of this change in the development of disease is unconfirmed.

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How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

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Types of Genetic Tests

A genetic test is a type of medical test that detects changes in genes, chromosomes or proteins. Today there are more than 77,000 genetic tests available.

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