Definition

Biallelic variants in the QARS1 gene, which is responsible for attaching an amino acid to its own tRNA during protein synthesis, disrupt the gene's function and lead to severe developmental epileptic encephalopathy; the clinical picture includes treatment-resistant multifocal seizures beginning in the neonatal period, severe developmental delay, microcephaly, and cerebral/cerebellar atrophy.

Gene/region examined

BRAT1 - Exon 1, BRAT1 - Exon 2, BRAT1 - Exon 3, BRAT1 - Exon 4, BRAT1 - Exon 5, BRAT1 - Exon 6, BRAT1 - Exon 7, BRAT1 - Exon 8, BRAT1 - Exon 9, BRAT1 - Exon 10, BRAT1 - Exon 11, BRAT1 - Exon 12, BRAT1 - Exon 13, BRAT1 - Exon 14

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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