Definition

Biallelic loss-of-function variants in the CECR1 (ADA2) gene cause adenosine deaminase 2 (ADA2) enzyme deficiency (DADA2), the first monogenic vasculitis syndrome to be described. Findings range from livedo reticularis/racemosa to polyarteritis nodosa and life-threatening stroke, along with fever and rash.

Gene/region examined

ADA2 - Exon 2, ADA2 - Exon 3, ADA2 - Exon 4, ADA2 - Exon 5, ADA2 - Exon 6, ADA2 - Exon 7, ADA2 - Exon 8, ADA2 - Exon 9, ADA2 - Exon 10

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Inherited, autosomal recessive (the classic Sneddon syndrome definition is usually sporadic; the ADA2-related subset is inherited).

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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