GENE REFERENCE / HGNC:1160

TWNK

twinkle mtDNA helicase

protein-coding gene10q24.31Gene information

What does this gene do?

The TWNK gene provides instructions for making two very similar proteins called Twinkle and Twinky. These proteins are found in the mitochondria, which are structures in which a process called oxidative phosphorylation occurs to convert the energy from food into a form that cells can use.

Mitochondria each contain a small amount of DNA, known as mitochondrial DNA (mtDNA), which is essential for the normal function of these structures. The Twinkle protein is involved in the production and maintenance of mtDNA. It functions as a mitochondrial DNA helicase, which means it binds to DNA and temporarily unwinds the two spiral strands (double helix) of the DNA molecule. This unwinding is necessary for copying (replicating) mtDNA. The function of the Twinky protein is unknown.

Source: MedlinePlus, National Library of Medicine. Source publication: 2020-08-18. Source review: 2014-12.

ClinGen reviews

ClinGen reviews the evidence linking a particular gene to a condition. Each rating below describes the strength of that link. It does not classify a variant in your DNA file.

Condition	Inheritance	Evidence
Perrault syndrome 5MONDO:0014504 · Evaluated 2026-01-21	Autosomal recessive	DefinitiveHearing Loss Gene Curation Expert Panel

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: 716
Submissions for variants in or overlapping this gene: 1,436
Submissions explicitly reporting this gene: 1,398
Alleles reported pathogenic / likely pathogenic: 80
VariationIDs with uncertain significance: 365
VariationIDs with conflicting classifications: 65

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 TWNK?

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 80 alleles in TWNK 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 TWNK.

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

Buy BioDecode See a sample report →Check file compatibility →