Definition

Mucopolysaccharidosis type I is an autosomal recessive disease characterized by accumulation of glycosaminoglycans in lysosomes due to deficiency of the alpha-L-iduronidase enzyme resulting from biallelic variants in the IDUA gene. Hurler, Hurler-Scheie, and Scheie syndromes are biochemically a single disease continuum; if left untreated, the Hurler form is fatal in early childhood due to cardiorespiratory complications.

Gene/region examined

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