GENE REFERENCE / HGNC:15925

SAMHD1

SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1

protein-coding gene20q11.23Gene information

What does this gene do?

The SAMHD1 gene provides instructions for making an enzyme that helps cut (cleave) molecules called deoxynucleoside triphosphates (dNTPs) into their deoxynucleoside and triphosphate components. The dNTP molecules are needed for the replication and maintenance of DNA in the body's cells, however; invading viruses such as the human immunodeficiency virus (HIV) also need dNTPs to make copies of themselves. Therefore, the amount of available dNTPs must be tightly controlled. The SAMHD1 enzyme helps regulate the amount of available dNTPs to both meet the needs of the body's cells and control viral infections.

The SAMHD1 enzyme is also thought to play a role in DNA repair and maintaining the stability of genetic material.

Source: MedlinePlus, National Library of Medicine. Source publication: 2024-09-26. Source review: 2024-09.

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
SAMHD1-related type 1 interferonopathyMONDO:0700260 · Evaluated 2024-07-01	Autosomal recessive	DefinitiveLeukodystrophy and Leukoencephalopathy 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: 1,076
Submissions for variants in or overlapping this gene: 1,593
Submissions explicitly reporting this gene: 1,550
Alleles reported pathogenic / likely pathogenic: 166
VariationIDs with uncertain significance: 373
VariationIDs with conflicting classifications: 35

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 SAMHD1?

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 166 alleles in SAMHD1 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 SAMHD1.

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

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