Definition

Autosomal dominant hypocalcemia type 1 (ADH1) results from gain-of-function variants in the CASR gene. Activating variants of the calcium-sensing receptor (CaSR) increase the receptor's sensitivity to calcium, suppressing PTH secretion and increasing urinary calcium excretion even at lower-than-normal serum calcium levels. Half of patients are mild/asymptomatic, while the other half present with paresthesia, carpopedal spasm and seizures; about 10 percent develop nephrocalcinosis/kidney stones.

Gene/region examined

CASR - Exon 1, CASR - Exon 2, CASR - Exon 3, CASR - Exon 4, CASR - Exon 5, CASR - Exon 6, CASR - Exon 7

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Hereditary, autosomal dominant (de novo cases have also been reported).

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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