Definition

Mucopolysaccharidosis type VII (Sly syndrome) is an autosomal recessive lysosomal storage disease caused by beta-glucuronidase enzyme deficiency resulting from biallelic variants in the GUSB gene. Enzyme deficiency leads to accumulation of glycosaminoglycans, causing dysostosis multiplex, joint restriction, short stature, and hepatosplenomegaly; the most severe form can present prenatally/perinatally with hydrops fetalis.

Gene/region examined

GUSB - Whole Gene

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

Go to term →

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

Go to term →

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.

Go to term →

How to Read a Genetic Test Result (Positive / Negative / VUS)

A genetic test result falls into three main categories

Go to term →

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.

Go to term →