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UniProtKB/Swiss-Prot P35523: Variant p.Gln552Arg

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

Variant position:  552
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 Glutamine (Q) to Arginine (R) at position 552 (Q552R, p.Gln552Arg).
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 (Q) to large size and basic (R)
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

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.

Involvement in disease:  Myotonia congenita, autosomal dominant (MCAD) [MIM:160800]: 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 dominant form (Thomsen disease) is less common and less severe than the autosomal recessive one (Becker disease). A milder form of autosomal dominant myotonia is characterized by isolated myotonia without muscle weakness, hypotrophy, or hypertrophy (myotonia levior). {ECO:0000269|PubMed:12661046, ECO:0000269|PubMed:26096614, ECO:0000269|PubMed:27653901, ECO:0000269|PubMed:27666773, ECO:0000269|PubMed:7581380, ECO:0000269|PubMed:7981750, ECO:0000269|PubMed:8112288, ECO:0000269|PubMed:8533761, ECO:0000269|PubMed:8845168, ECO:0000269|PubMed:9122265, 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 MCAD and MCAR; also found in myotonia levior; reduced chloride transport; changed calcium channel activity; changed channel gating; weak dominant negative effect.
Any additional useful information about the variant.

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



Sequence information

Variant position:  552
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:   LTGAVSHTVSTAVICFELTG  Q IAHILPMMVAVILANMVAQS
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                         LTGAVSHTVSTAVICFELTGQIAHILPMMVAVILANMVAQS

                              LTGAVSHTVSTAVICFELTGQIAHILPMMVAVILANMVAQS

Mouse                         LTGAVSHTVSTAVICFELTGQIAHILPMMVAVILANMVAQS

Rat                           LTGAVSHTVSTAVICFELTGQIAHILPMMVAVILANMVAQS

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 522 – 554 Helical


Literature citations

A novel alteration of muscle chloride channel gating in myotonia levior.
Ryan A.; Ruedel R.; Kuchenbecker M.; Fahlke C.;
J. Physiol. (Lond.) 545:345-354(2002)
Cited for: FUNCTION; SUBCELLULAR LOCATION; CHARACTERIZATION OF VARIANT MYOTONIA LEVIOR ARG-552;

Myotonia levior is a chloride channel disorder.
Lehmann-Horn F.; Mailaender V.; Heine R.; George A.L. Jr.;
Hum. Mol. Genet. 4:1397-1402(1995)
Cited for: VARIANT MCAD MET-290; VARIANT MYOTONIA LEVIOR ARG-552; VARIANT TRP-118;

Mutations in dominant human myotonia congenita drastically alter the voltage dependence of the CIC-1 chloride channel.
Pusch M.; Steinmeyer K.; Koch M.C.; Jentsch T.J.;
Neuron 15:1455-1463(1995)
Cited for: VARIANT MCAD MET-290; VARIANT MCAR LYS-291; CHARACTERIZATION OF VARIANTS MCAD MET-290; GLN-317 AND LEU-480; CHARACTERIZATION OF VARIANT MCAR LYS-291; CHARACTERIZATION OF VARIANT MYOTONIA LEVIOR ARG-552; MUTAGENESIS OF ILE-290 AND GLU-291;

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.