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UniProtKB/Swiss-Prot P35499: Variant p.Thr704Met

Sodium channel protein type 4 subunit alpha
Gene: SCN4A
Variant information

Variant position:  704
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Type of variant:  Disease [Disclaimer]
The variants are classified into three categories: Disease, Polymorphism and Unclassified.
  • Disease: Variants implicated in disease according to literature reports.
  • Polymorphism: Variants not reported to be implicated in disease.
  • Unclassified: Variants with uncertain implication in disease according to literature reports. Evidence against or in favor of a pathogenic role is limited and/or conflicting.

Residue change:  From Threonine (T) to Methionine (M) at position 704 (T704M, p.Thr704Met).
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:  Change from medium size and polar (T) to medium size and hydrophobic (M)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -1
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

Variant description:  In HYPP and PMC.
Any additional useful information about the variant.

Other resources:  
Links to websites of interest for the variant.



Sequence information

Variant position:  704
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  1836
The length of the canonical sequence.

Location on the sequence:   PTLNMLIKIIGNSVGALGNL  T LVLAIIVFIFAVVGMQLFGK
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: 
The multiple alignment of the region surrounding the variant against various orthologous sequences.

Human                         PTLNMLIKIIGNSVGALGNLTLVLAIIVFIFAVVGMQLFGK

Mouse                         PTLNMLIKIIGNSVGALGNLTLVLAIIVFIFAVVGMQLFGK

Rat                           PTLNMLIKIIGNSVGALGNLTLVLAIIVFIFAVVGMQLFGK

Horse                         PTLNMFIRIIGNSGGGLGNLTLVLAIIVVNFSVVGMQLFGK

Sequence annotation in neighborhood:  
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 – 1836 Sodium channel protein type 4 subunit alpha
Transmembrane 699 – 717 Helical; Name=S5 of repeat II
Repeat 560 – 832 II
Helix 703 – 726


Literature citations

Identification of a mutation in the gene causing hyperkalemic periodic paralysis.
Ptacek L.J.; George A.L. Jr.; Griggs R.C.; Tawil R.; Kallen R.G.; Barchi R.L.; Robertson M.; Leppert M.F.;
Cell 67:1021-1027(1991)
Cited for: VARIANT HYPP MET-704;

What causes paramyotonia in the United Kingdom? Common and new SCN4A mutations revealed.
Matthews E.; Tan S.V.; Fialho D.; Sweeney M.G.; Sud R.; Haworth A.; Stanley E.; Cea G.; Davis M.B.; Hanna M.G.;
Neurology 70:50-53(2008)
Cited for: VARIANTS PMC LYS-270; MET-704; ALA-1306; GLU-1306; MET-1313; PRO-1436; CYS-1448; HIS-1448; LEU-1448; GLU-1456; SER-1473 AND MET-1589;

Tubular aggregates in paralysis periodica paramyotonica with T704M mutation of SCN4A.
Luan X.; Chen B.; Liu Y.; Zheng R.; Zhang W.; Yuan Y.;
Neuropathology 29:579-584(2009)
Cited for: VARIANT PMC MET-704;

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.