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UniProtKB/Swiss-Prot P51787: Variant p.Leu273Phe

Potassium voltage-gated channel subfamily KQT member 1
Gene: KCNQ1
Variant information

Variant position:  273
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 Leucine (L) to Phenylalanine (F) at position 273 (L273F, p.Leu273Phe).
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 hydrophobic (L) to large size and aromatic (F)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  0
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

Involvement in disease:  Long QT syndrome 1 (LQT1) [MIM:192500]: A heart disorder characterized by a prolonged QT interval on the ECG and polymorphic ventricular arrhythmias. They cause syncope and sudden death in response to exercise or emotional stress, and can present with a sentinel event of sudden cardiac death in infancy. {ECO:0000269|PubMed:10024302, ECO:0000269|PubMed:10220144, ECO:0000269|PubMed:10220146, ECO:0000269|PubMed:10367071, ECO:0000269|PubMed:10409658, ECO:0000269|PubMed:10482963, ECO:0000269|PubMed:10728423, ECO:0000269|PubMed:10973849, ECO:0000269|PubMed:11799244, ECO:0000269|PubMed:12442276, ECO:0000269|PubMed:15840476, ECO:0000269|PubMed:16414944, ECO:0000269|PubMed:16922724, ECO:0000269|PubMed:18165683, ECO:0000269|PubMed:18400097, ECO:0000269|PubMed:19540844, ECO:0000269|PubMed:19716085, ECO:0000269|PubMed:19808498, ECO:0000269|PubMed:21241800, ECO:0000269|PubMed:24184248, ECO:0000269|PubMed:24269949, ECO:0000269|PubMed:24713462, ECO:0000269|PubMed:25037568, ECO:0000269|PubMed:25139741, ECO:0000269|PubMed:25705178, ECO:0000269|PubMed:8528244, ECO:0000269|PubMed:8818942, ECO:0000269|PubMed:8872472, ECO:0000269|PubMed:9024139, ECO:0000269|PubMed:9272155, ECO:0000269|PubMed:9302275, ECO:0000269|PubMed:9312006, ECO:0000269|PubMed:9323054, ECO:0000269|PubMed:9386136, ECO:0000269|PubMed:9482580, ECO:0000269|PubMed:9570196, ECO:0000269|PubMed:9641694, ECO:0000269|PubMed:9693036, ECO:0000269|PubMed:9702906, ECO:0000269|PubMed:9799083, ECO:0000269|PubMed:9927399, ECO:0000269|Ref.31}. Note=The disease is caused by mutations affecting the gene represented in this entry.
The name and a short description of the disease associated with the variant. For more information about the disease, the user can refer to OMIM, following the link provided after the disease acronym.

Variant description:  In LQT1; functional channel with reduced macroscopic conductance (homomultimers); alteration of normal KVLQT1 function (mut/wt homomultimers).
Any additional useful information about the variant.

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



Sequence information

Variant position:  273
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  676
The length of the canonical sequence.

Location on the sequence:   SVVFIHRQELITTLYIGFLG  L IFSSYFVYLAEKDAVNESGR
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                         SVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGR

Mouse                         SVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGR

Rat                           SVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGR

Rabbit                        SVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAVNESGR

Xenopus laevis                SVVFIHRQELITTLYIGFLGLIFSSYFVYLAEKDAIDSSGE

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 – 676 Potassium voltage-gated channel subfamily KQT member 1
Transmembrane 262 – 282 Helical; Name=Segment S5
Glycosylation 289 – 289 N-linked (GlcNAc...) asparagine
Helix 259 – 284


Literature citations

Dominant-negative KvLQT1 mutations underlie the LQT1 form of long QT syndrome.
Shalaby F.Y.; Levesque P.C.; Yang W.-P.; Little W.A.; Conder M.L.; Jenkins-West T.; Blanar M.A.;
Circulation 96:1733-1736(1997)
Cited for: CHARACTERIZATION OF VARIANTS LQT1 PRO-178; PHE-273 AND ILE-312;

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 of pathogenic mutations and associated polymorphisms in a cohort of 44 unrelated patients with long QT syndrome.
Millat G.; Chevalier P.; Restier-Miron L.; Da Costa A.; Bouvagnet P.; Kugener B.; Fayol L.; Gonzalez Armengod C.; Oddou B.; Chanavat V.; Froidefond E.; Perraudin R.; Rousson R.; Rodriguez-Lafrasse C.;
Clin. Genet. 70:214-227(2006)
Cited for: VARIANTS LQT1 CYS-231; PRO-243; CYS-259; HIS-259; PHE-273; SER-314; GLU-316; VAL-341; VAL-344 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.