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UniProtKB/Swiss-Prot P35523: Variant p.Gly270Val

Chloride channel protein 1
Gene: CLCN1
Chromosomal location: 7q35
Variant information

Variant position:  270
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 Glycine (G) to Valine (V) at position 270 (G270V, p.Gly270Val).
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 glycine (G) to medium size and hydrophobic (V)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -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

Involvement in disease:  Myotonia congenita, autosomal recessive (MCAR) [MIM:255700]: A non-dystrophic skeletal muscle disorder characterized by muscle stiffness and an inability of the muscle to relax after voluntary contraction. Most patients have symptom onset in the legs, which later progresses to the arms, neck, and facial muscles. Many patients show marked hypertrophy of the lower limb muscles. The autosomal recessive form (Becker disease) is more severe than the autosomal dominant one (Thomsen disease). {ECO:0000269|PubMed:10215406, ECO:0000269|PubMed:10644771, ECO:0000269|PubMed:11113225, ECO:0000269|PubMed:12661046, ECO:0000269|PubMed:1379744, ECO:0000269|PubMed:19697366, ECO:0000269|PubMed:22521272, ECO:0000269|PubMed:22641783, ECO:0000269|PubMed:26007199, ECO:0000269|PubMed:26096614, ECO:0000269|PubMed:26502825, ECO:0000269|PubMed:26510092, ECO:0000269|PubMed:7874130, ECO:0000269|PubMed:7951242, ECO:0000269|PubMed:7981681, ECO:0000269|PubMed:8533761, ECO:0000269|PubMed:8571958, ECO:0000269|PubMed:8845168, ECO:0000269|PubMed:9566422, ECO:0000269|PubMed:9736777}. 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 MCAR; decreased chloride channel activity.
Any additional useful information about the variant.



Sequence information

Variant position:  270
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  988
The length of the canonical sequence.

Location on the sequence:   MSVFCGVYEQPYYYSDILTV  G CAVGVGCCFGTPLGGVLFSI
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                         MSVFCGVYEQPYYYSDILTVGCAVGVGCCFGTPLGGVLFSI

                              MSMFCGVYEQPYYYTDMLTVGCAVGVGCCFGTPLGGVLFSI

Mouse                         MSMFSGVYEQPYYYTDILTVGCAVGVGCCFGTPLGGVLFSI

Rat                           MSMFSGVYEQPYYYTDILTVGCAVGVGCCFGTPLGGVLFSI

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 – 988 Chloride channel protein 1
Intramembrane 269 – 290 Helical
Mutagenesis 290 – 290 I -> CEFGKLQTVY. Changed chloride channel activity; changed gating of the channel.
Helix 263 – 279


Literature citations

Clinical, molecular, and functional characterization of CLCN1 mutations in three families with recessive myotonia congenita.
Portaro S.; Altamura C.; Licata N.; Camerino G.M.; Imbrici P.; Musumeci O.; Rodolico C.; Conte Camerino D.; Toscano A.; Desaphy J.F.;
NeuroMolecular Med. 17:285-296(2015)
Cited for: VARIANTS MCAR ALA-82; SER-190; VAL-270 AND TRP-453; CHARACTERIZATION OF VARIANTS MCAR ALA-82; SER-190; VAL-270 AND TRP-453; FUNCTION;

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.