Definition

This is the most common chromosomal abnormality seen in CLL; the deletion at 13q14 may encompass the RB1 tumor suppressor gene and/or the nearby miR-15a/16-1 cluster. When found alone (isolated), it defines a subgroup in which CLL generally follows an indolent course. In patients with isolated del(13q), median overall survival is 17 years, the best prognosis group in the Dohner hierarchy, although the true prognostic determinant has been shown to be the deletion burden (clone size).

Method

FISH analysis

Accepted Sample Types

Peripheral blood, Bone marrow (heparin), Fresh tumor tissue, FFPE

Description

RB and MM diagnosis and monitoring.

Inheritance

This is a somatic chromosomal deletion acquired later in the leukemic clone; it is not a hereditary predisposition.

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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