Definition

The RAPSN gene encodes the rapsyn adaptor protein, which anchors acetylcholine receptors to the cytoskeleton at the neuromuscular junction. Impaired AChR clustering leads to fatigable muscle weakness from birth, hypotonia, ptosis, and feeding difficulty; in severe cases it can extend to fetal akinesia/arthrogryposis. It generally responds to cholinesterase inhibitors.

Gene/region examined

RAPSN - Exon 1, RAPSN - Exon 2, RAPSN - Exon 3, RAPSN - Exon 4, RAPSN - Exon 5, RAPSN - Exon 6, RAPSN - Exon 7, RAPSN - Exon 8

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Hereditary, autosomal recessive.

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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