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Genetics Library / Genes / TNNI2

GENE REFERENCE / HGNC:11946

TNNI2

troponin I2, fast skeletal type

protein-coding gene11p15.5Gene information

What does this gene do?

The TNNI2 gene provides instructions for making one form of a protein called troponin I. The troponin I protein produced from the TNNI2 gene is found in skeletal muscles, which are the muscles used for movement. Troponin I is one of three proteins that make up the troponin complex in muscle cells. The troponin complex, along with calcium, helps regulate muscle tensing (contraction).

The troponin complex is part of a structure called the sarcomere, which is the basic unit of muscle contraction. Sarcomeres contain thick and thin filaments. The overlapping thick and thin filaments attach (bind) to each other and release, which allows the filaments to move relative to one another so that muscles can contract.

When calcium levels are low, the troponin complex blocks the binding between the thick and thin filaments that is needed for muscle contraction. An increase in calcium levels causes structural changes in the troponin complex, which exposes the binding sites and allows the thick and thin filaments to interact, leading to muscle contraction.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2015-06.

Related condition topics

MedlinePlus mentions this gene in the condition pages below. These links alone do not show that the gene causes a condition.

ClinGen reviews

We found no matching ClinGen review in the data used here. This does not rule out a link between the gene and a condition.

ClinVar records

These numbers show what has been submitted to ClinVar. They cannot tell you how likely you are to have a condition.

Submitted alleles
165
Submissions for variants in or overlapping this gene
271
Submissions explicitly reporting this gene
221
Alleles reported pathogenic / likely pathogenic
15
VariationIDs with uncertain significance
61
VariationIDs with conflicting classifications
6

The rows count different things: alleles, submissions or VariationIDs. Their categories can overlap, so do not add them together. Pathogenic/likely pathogenic counts exclude structural variants that merely overlap a gene. A dash in the source means “not reported,” not zero.

NCBI produces the gene-summary file each week using counts recorded at the start of the month. The numbers may differ from those on the live ClinVar website. Read the field definitions ↗

View this gene in ClinVar ↗

YOUR DNA FILE

Can your DNA file tell you about TNNI2?

From a DNA test kit (such as 23andMe, AncestryDNA or MyHeritage). These kits check a fixed list of about 600,000 to 700,000 positions across your whole genome. ClinVar lists 15 alleles in TNNI2 reported as pathogenic or likely pathogenic. A kit checks only some of these positions, and often none of them.

From whole genome sequencing (a VCF file). Sequencing reads most of your genome. Your file lists the places where your DNA differs from the reference genome. Some regions are hard to sequence, including parts of some genes that have near-identical copies elsewhere, and a VCF file does not record which positions were read well.

If a variant is not in your file, that does not mean you don’t have it.

What BioDecode checks

BioDecode compares every variant in your file with ClinVar, on your own computer. For each match, it shows the ClinVar classification, the review status and the condition it was reported for. Your file is not uploaded.

A ClinVar classification applies to one particular variant and the condition it was reported for. It does not tell you about other variants in TNNI2.

BioDecode cannot fill gaps in your test, diagnose a condition or replace clinical testing.

Sources and dates

The source information on this page last changed on 2026-10-10.

HGNC Source details

Open source record ↗

Source release: Fri, 09 Oct 2026 13:40:45 GMT
Source record updated: 2023-01-20

SHA-256: e4cd9c6d7120051b80e5e61d2aeb98bd6a541ddd21f428a6eab922c11242e053

MedlinePlus Source details

Open source record ↗

Source release: Sat, 10 Oct 2026 05:16:07 GMT
Source publication: 2020-08-18
Source review: 2015-06

SHA-256: fdc8bd614310c12718379cef6569962e5d0e791cecabcc355b53a72816ac263a

ClinVar Source details

Open source record ↗

Source release: Sun, 04 Oct 2026 13:15:29 GMT

SHA-256: 126d9e5bded1d43c0380ac6684c86f9aab056d2ff2be93d743e408ed917ae558

About the library sources · Latest validated release · Record fb416430cd5a