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UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot Q9NV35: Variant p.Val18Ile

Nucleotide triphosphate diphosphatase NUDT15
Gene: NUDT15
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Variant information Variant position: help 18 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant: help LB/B The variants are classified into three categories: LP/P, LB/B and US.
  • LP/P: likely pathogenic or pathogenic.
  • LB/B: likely benign or benign.
  • US: uncertain significance

Residue change: help From Valine (V) to Isoleucine (I) at position 18 (V18I, p.Val18Ile). Indicates the amino acid change of the variant. The one-letter and three-letter codes for amino acids used in UniProtKB/Swiss-Prot are those adopted by the commission on Biochemical Nomenclature of the IUPAC-IUB.
Physico-chemical properties: help Similar physico-chemical property. Both residues are medium size and hydrophobic. The physico-chemical property of the reference and variant residues and the change implicated.
BLOSUM score: help 3 The score within a Blosum matrix for the corresponding wild-type to variant amino acid change. The log-odds score measures the logarithm for the ratio of the likelihood of two amino acids appearing by chance. The Blosum62 substitution matrix is used. This substitution matrix contains scores for all possible exchanges of one amino acid with another:
  • Lowest score: -4 (low probability of substitution).
  • Highest score: 11 (high probability of substitution).
More information can be found on the following page

Polymorphism: help Polymorphic NUDT15 variants define the poor metabolism of thiopurines 2 genetic locus (THPM2) [MIM:616903]. Thiopurines are used as immunosuppressants or cytotoxic drugs and are prescribed for a variety of clinical conditions including leukemia, autoimmune disease and organ transplantation. Patients with low NUDT15 activities have an increased risk for toxic effects after receiving standard doses of thiopurine drugs. Additional information on the polymorphism described.
Variant description: help Risk factor for thiopurines toxicity; decreased thermostability; decreased diphosphatase activity towards 6-thio-dGTP and 6-thio-GTP. Any additional useful information about the variant.
Other resources: help Links to websites of interest for the variant.


Sequence information Variant position: help 18 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length: help 164 The length of the canonical sequence.
Location on the sequence: help MTASAQPRGRRPGVGVG V VVTSCKHPRCVLLGKRKGSV The residue change on the sequence. Unless the variant is located at the beginning or at the end of the protein sequence, both residues upstream (20) and downstream (20) of the variant will be shown.
Residue conservation: help The multiple alignment of the region surrounding the variant against various orthologous sequences.
Human                         MTASAQPRGRRPGVGVGVVVTSCKHPRCVLLGKRKGSV

Mouse                         MAANAEPR-RRPGVGVGVVVLSCEHPRCVLLGKRKGSF

Sequence annotation in neighborhood: help The regions or sites of interest surrounding the variant. In general the features listed are posttranslational modifications, binding sites, enzyme active sites, local secondary structure or other characteristics reported in the cited references. The "Sequence annotation in neighborhood" lines have a fixed format:
  • Type: the type of sequence feature.
  • Positions: endpoints of the sequence feature.
  • Description: contains additional information about the feature.
TypePositionsDescription
Chain 1 – 164 Nucleotide triphosphate diphosphatase NUDT15
Domain 9 – 145 Nudix hydrolase
Beta strand 15 – 21



Literature citations
NUDT15 polymorphisms alter thiopurine metabolism and hematopoietic toxicity.
Moriyama T.; Nishii R.; Perez-Andreu V.; Yang W.; Klussmann F.A.; Zhao X.; Lin T.N.; Hoshitsuki K.; Nersting J.; Kihira K.; Hofmann U.; Komada Y.; Kato M.; McCorkle R.; Li L.; Koh K.; Najera C.R.; Kham S.K.; Isobe T.; Chen Z.; Chiew E.K.; Bhojwani D.; Jeffries C.; Lu Y.; Schwab M.; Inaba H.; Pui C.H.; Relling M.V.; Manabe A.; Hori H.; Schmiegelow K.; Yeoh A.E.; Evans W.E.; Yang J.J.;
Nat. Genet. 48:367-373(2016)
Cited for: POLYMORPHISM; VARIANTS ILE-18; GLY-VAL-18 INS; CYS-139 AND HIS-139; CHARACTERIZATION OF VARIANTS ILE-18; GLY-VAL-18 INS; CYS-139 AND HIS-139; CATALYTIC ACTIVITY;
Disclaimer: Any medical or genetic information present in this entry is provided for research, educational and informational purposes only. They are not in any way intended to be used as a substitute for professional medical advice, diagnostic, treatment or care.