Definition

A contiguous gene microdeletion spanning the NF1 gene in the 17q11.2 region and surrounding neighboring genes leads to 'NF1 microdeletion syndrome,' which presents with a more severe phenotype than classic NF1: early-onset, numerous cutaneous neurofibromas, prominent dysmorphic facial features, developmental delay, and an increased risk of malignant peripheral nerve sheath tumor. In approximately 5-10% of NF1 patients, the etiology is a whole-gene deletion.

Method

FISH analysis

Accepted sample types

Amniotic fluid, Chorionic villus, Cord blood

Inheritance

Mostly de novo; when inherited, autosomal dominant.

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 →