# SAMHD1

Source: https://onco.cc/targets/samhd1/  
OnCo record `samhd1` (Target). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

SAMHD1 (Deoxynucleoside triphosphate triphosphohydrolase SAMHD1) is a gene whose normal job is to hold cell growth in check. The public catalogues list it as a tumour suppressor and a DNA repair gene, and it is called a cancer driver by mutation analysis of patient cohorts. Tied to Multiple myeloma.

## Summary

Protein that acts both as a host restriction factor involved in defense response to virus and as a regulator of DNA end resection at stalled replication forks. Has deoxynucleoside triphosphate (dNTPase) activity, which is required to restrict infection by viruses, such as HIV-1: dNTPase activity reduces cellular dNTP levels to levels too low for retroviral reverse transcription to occur, blocking early-stage virus replication in dendritic and other myeloid cells. Likewise, suppresses LINE-1 retrotransposon activity.

IntOGen calls it a driver in 1 cohort (0 activating, 1 loss-of-function), covering Plasma Cell Myeloma.

## Fields

- Kind: Target
- Last checked: 2026-09-23
- Also known as: SAM and HD domain containing deoxynucleoside triphosphate triphosphohydrolase 1; Deoxynucleoside triphosphate triphosphohydrolase SAMHD1; SBBI88; Mg11; HDDC1; MOP-5; AGS5
- Tags: cancer-genes-wave
- Symbol: SAMHD1
- Class: tumor-suppressor
- Biology: Protein that acts both as a host restriction factor involved in defense response to virus and as a regulator of DNA end resection at stalled replication forks. Has deoxynucleoside triphosphate (dNTPase) activity, which is required to restrict infection by viruses, such as HIV-1: dNTPase activity reduces cellular dNTP levels to levels too low for retroviral reverse transcription to occur, blocking early-stage virus replication in dendritic and other myeloid cells. Likewise, suppresses LINE-1 retrotransposon activity. Not able to restrict infection by HIV-2 virus; because restriction activity is counteracted by HIV-2 viral protein Vpx. In addition to virus restriction, dNTPase activity acts as a regulator of DNA precursor pools by regulating dNTP pools. Phosphorylation at Thr-592 acts as a switch to control dNTPase-dependent and -independent functions: it inhibits dNTPase activity and ability to restrict infection by viruses, while it promotes DNA end resection at stalled replication forks. Location: Nucleus; Chromosome (UniProt). Locus 20q11.23 (HGNC).
- Where found: Multiple myeloma: IntOGen driver in 1 cohort (PCM)

## Notes

- Written by scripts/fetch-cancer-genes.ts from CIViC, Open Targets, IntOGen, HGNC and UniProt; the function text is UniProt's, condensed and in UK spelling. Roles: IntOGen calls it a loss-of-function (LoF) driver in 1 cohort; UniProt keyword "DNA repair". Evidence tier "cohort-driver" is the strongest of those signals.
- Prevalence not recorded: none of the sources gives a positivity rate.

## Sources

- HGNC HGNC:15925: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:15925
- UniProt Q9Y3Z3: https://www.uniprot.org/uniprotkb/Q9Y3Z3/entry
- NCBI Gene 25939: https://www.ncbi.nlm.nih.gov/gene/25939
- Ensembl ENSG00000101347: https://www.ensembl.org/Homo_sapiens/Gene/Summary?g=ENSG00000101347

## Connected records

- collections: [IntOGen](https://onco.cc/collections/intogen/)
- cancers: [Multiple myeloma](https://onco.cc/cancers/multiple-myeloma/)

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JSON: https://onco.cc/api/v1/entities/samhd1.json