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UniProtKB/Swiss-Prot variant pages

UniProtKB/Swiss-Prot P51787: Variant p.Val254Met

Potassium voltage-gated channel subfamily KQT member 1
Gene: KCNQ1
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Variant information Variant position: help 254 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Type of variant: help LP/P [Disclaimer] 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 Methionine (M) at position 254 (V254M, p.Val254Met). 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 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: help In LQT1; associated in cis with M-417 in a patient. Any additional useful information about the variant.
Other resources: help Links to websites of interest for the variant.


Sequence information Variant position: help 254 The position of the amino-acid change on the UniProtKB canonical protein sequence.
Protein sequence length: help 676 The length of the canonical sequence.
Location on the sequence: help QILRMLHVDRQGGTWRLLGS V VFIHRQELITTLYIGFLGLI 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                         QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

Mouse                         QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

Rat                           QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

Pig                           QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

Rabbit                        QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

Xenopus laevis                QILRMLHVDRQGGTWRLLGSVVFIHRQELITTLYIGFLGLI

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 – 676 Potassium voltage-gated channel subfamily KQT member 1
Topological domain 249 – 261 Cytoplasmic
Helix 246 – 284



Literature citations
A severe form of long-QT syndrome caused by KVLQT1 mutations located in cis (Abstract #2051).
Wedekind H.; Schulze-Bahr E.; Lange S.; Rubie C.; Haverkamp W.; Hoerdt M.; Borggrefe M.; Assmann G.; Breithardt G.; Funke H.;
Cited for: VARIANTS LQT1 MET-254 AND MET-417; KVLQT1 C-terminal missense mutation causes a forme fruste long-QT syndrome.
Donger C.; Denjoy I.; Berthet M.; Neyroud N.; Cruaud C.; Bennaceur M.; Chivoret G.; Schwartz K.; Coumel P.; Guicheney P.;
Circulation 96:2778-2781(1997)
Cited for: VARIANTS LQT1 ARG-168; CYS-174; GLN-190; MET-254; LYS-261; ASP-269; ARG-309; SER-314; SER-315; ALA-320; ARG-325; VAL-341; PHE-342; VAL-344; THR-371 AND CYS-555; Spectrum of mutations in long-QT syndrome genes. KVLQT1, HERG, SCN5A, KCNE1, and KCNE2.
Splawski I.; Shen J.; Timothy K.W.; Lehmann M.H.; Priori S.G.; Robinson J.L.; Moss A.J.; Schwartz P.J.; Towbin J.A.; Vincent G.M.; Keating M.T.;
Circulation 102:1178-1185(2000)
Cited for: VARIANTS LQT1 CYS-111; LYS-160; ARG-168; HIS-174; SER-179; SER-184; PRO-194; LEU-225; CYS-243; ARG-248; MET-254; PRO-266; ASP-269; PHE-273; ILE-310; ILE-312; ARG-325; GLU-341; VAL-341; TRP-349; GLN-366; ILE-391; ARG-448; PHE-566; CYS-583 AND GLN-594; Compendium of cardiac channel mutations in 541 consecutive unrelated patients referred for long QT syndrome genetic testing.
Tester D.J.; Will M.L.; Haglund C.M.; Ackerman M.J.;
Heart Rhythm 2:507-517(2005)
Cited for: VARIANTS LQT1 71-ALA--PRO-73 DEL; THR-73; GLY-115; TYR-122; ILE-133; PHE-136; LYS-160; ARG-168; CYS-174; GLN-190; PHE-204; LEU-225; ASN-235; ASN-242; CYS-243; MET-254; 254-VAL--PHE-256 DEL; CYS-259; LEU-259; ASP-261; PRO-266; SER-269; ASP-269; PHE-273; ARG-273; SER-276 DEL; LEU-277; HIS-278; LYS-290; ASP-292; CYS-293; VAL-302; ARG-304; SER-305; ILE-312; SER-314; ARG-314; ASP-314; CYS-315; ARG-316; ALA-322; PHE-339 DEL; VAL-341; SER-343; GLU-344; VAL-344; GLU-345; TRP-349; PRO-353; ARG-362; TRP-366; HIS-374; SER-380; TYR-389; TRP-452; GLY-524; GLU-526; TRP-539; LEU-546; CYS-555; HIS-555; TYR-566; SER-567; ARG-568; MET-587; THR-590; HIS-591; GLN-594; MET-619 AND SER-626; Spectrum and prevalence of mutations from the first 2,500 consecutive unrelated patients referred for the FAMILION long QT syndrome genetic test.
Kapplinger J.D.; Tester D.J.; Salisbury B.A.; Carr J.L.; Harris-Kerr C.; Pollevick G.D.; Wilde A.A.; Ackerman M.J.;
Heart Rhythm 6:1297-1303(2009)
Cited for: VARIANTS LQT1 VAL-2; SER-7; THR-46; 64-PRO--PRO-70 DEL; PHE-66; THR-73; CYS-111; LEU-117; LEU-127; ILE-133; PRO-134; ALA-144; MET-153; MET-162; ARG-168; MET-172; CYS-174; HIS-174; THR-178; SER-179; HIS-184; ARG-186; GLN-190; LEU-190; TRP-195; VAL-198; ALA-199; MET-204; MET-215; MET-224; LEU-225; CYS-231; HIS-231; ASN-235; GLY-241; ASN-242; CYS-243; PRO-250; MET-254; CYS-259; LEU-259; VAL-262; PRO-266; SER-268; ASP-269; SER-269; ASP-272; PHE-273; VAL-274; LEU-277; PRO-277; GLU-280; CYS-281; PRO-282; GLY-283; ASP-292; CYS-293; GLU-302; VAL-302; PRO-303; ARG-305; SER-305; ARG-306; ILE-312; CYS-314; SER-314; CYS-315; VAL-316; SER-320; ALA-322; MET-322; ARG-325; TYR-339; GLU-341; GLY-341; VAL-341; PHE-342; LEU-343; ARG-350; SER-351; ARG-354; MET-360; ARG-362; HIS-365; GLN-366; TRP-366; HIS-374; GLY-379; LYS-385; PRO-389; THR-391 INS; TRP-397; ARG-398; GLU-446; LEU-448; TRP-451; SER-460; LEU-477; TRP-511; GLN-518; ARG-520; SER-522; GLY-524; THR-525; VAL-525; TRP-533; GLN-539; TRP-539; ILE-541; LYS-543; LEU-546; ARG-547; CYS-555; HIS-555; SER-555; GLU-557; PHE-566; PRO-566; TYR-566; THR-567; ARG-568; GLU-569; LEU-571; MET-587; ASP-589; CYS-591; HIS-591; GLN-594; PRO-594; GLU-596 DEL; LYS-596; MET-600; ASN-611; HIS-614 DEL; SER-626 AND ARG-635;
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.