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UniProtKB/Swiss-Prot P02489: Variant p.Arg21Leu

Alpha-crystallin A chain
Variant information

Variant position:  21
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 Arginine (R) to Leucine (L) at position 21 (R21L, p.Arg21Leu).
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 large size and basic (R) to medium size and hydrophobic (L)
The physico-chemical property of the reference and variant residues and the change implicated.

BLOSUM score:  -2
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:  Cataract 9, multiple types (CTRCT9) [MIM:604219]: An opacification of the crystalline lens of the eye that frequently results in visual impairment or blindness. Opacities vary in morphology, are often confined to a portion of the lens, and may be static or progressive. In general, the more posteriorly located and dense an opacity, the greater the impact on visual function. CTRCT9 includes nuclear, zonular central nuclear, anterior polar, cortical, embryonal, anterior subcapsular, fan-shaped, and total cataracts, among others. In some cases cataract is associated with microcornea without any other systemic anomaly or dysmorphism. Microcornea is defined by a corneal diameter inferior to 10 mm in both meridians in an otherwise normal eye. {ECO:0000269|PubMed:11123904, ECO:0000269|PubMed:14512969, ECO:0000269|PubMed:16453125, ECO:0000269|PubMed:18302245, ECO:0000269|PubMed:18407550, ECO:0000269|PubMed:23508780, ECO:0000269|PubMed:9467006}. 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 CTRCT9; associated with macular hypoplasia and a generally hypopigmented fundus.
Any additional useful information about the variant.

Sequence information

Variant position:  21
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  173
The length of the canonical sequence.

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.













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.

Chain 1 – 173 Alpha-crystallin A chain
Chain 1 – 172 Alpha-crystallin A(1-172)
Chain 1 – 168 Alpha-crystallin A(1-168)
Chain 1 – 162 Alpha-crystallin A(1-162)
Region 1 – 63 Required for complex formation with BFSP1 and BFSP2
Site 1 – 1 Susceptible to oxidation
Site 18 – 18 Susceptible to oxidation
Site 34 – 34 Susceptible to oxidation
Modified residue 1 – 1 N-acetylmethionine
Modified residue 6 – 6 Deamidated glutamine; partial

Literature citations

Congenital cataract and macular hypoplasia in humans associated with a de novo mutation in CRYAA and compound heterozygous mutations in P.
Graw J.; Klopp N.; Illig T.; Preising M.N.; Lorenz B.;
Graefes Arch. Clin. Exp. Ophthalmol. 244:912-919(2006)
Cited for: VARIANT CTRCT9 LEU-21;

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.