Definition

Chorionic villus sampling (CVS) is a first trimester prenatal karyotype method performed by taking placental tissue at 10 to 13 weeks of pregnancy. It has an accuracy of ~97.5 to 99.6% for detecting non-mosaic whole chromosome anomalies, and results can generally be obtained within 48 hours.

Method

Cell culture

Accepted sample types

Chorionic villus

Inheritance

Reflects the fetal-derived (placental/trophoblast) chromosome structure; confirmation with amniocentesis may be needed in some cases due to placental mosaicism.

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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