Definition

The PSAP gene encodes prosaposin, the precursor of four saposin proteins (SapA-D); these saposins are cofactors required for the lysosomal breakdown of sphingolipids. Involvement of both alleles leads to deficiency of prosaposin and all saposins, causing the clinical features of Gaucher, Krabbe, metachromatic leukodystrophy and Farber diseases to appear together; symptoms begin at birth or shortly after and the course is fatal in infancy.

Gene/region examined

PSAP - Full Gene

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Hereditary, autosomal recessive (AR).

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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