Definition

Immunodeficiency 75 with lymphoproliferation (IMD75) is an autosomal recessive immunological disorder resulting from homozygous pathogenic variants in the TET2 gene. Loss of TET2 function leads to abnormal differentiation and immune dysregulation in hematopoietic cells; patients usually present in infancy with severe recurrent infections, and hepatosplenomegaly, lymphadenopathy and lymphoproliferative disease/lymphomas can develop.

Gene/region examined

TET2 - Exon 3, TET2 - Exon 4, TET2 - Exon 5, TET2 - Exon 6, TET2 - Exon 7, TET2 - Exon 8, TET2 - Exon 9, TET2 - Exon 10, TET2 - Exon 11

Method

Sequence analysis

Accepted sample types

EDTA blood, AF, CVS

Inheritance

Hereditary, autosomal recessive (note: somatic variants in TET2 are also associated separately with clonal hematopoiesis and myeloid malignancy, but the variants causing IMD75 are germline/hereditary).

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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