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UniProtKB/Swiss-Prot Q9UBM7: Variant p.Thr289Ile

7-dehydrocholesterol reductase
Gene: DHCR7
Chromosomal location: 11q13.2-q13.5
Variant information

Variant position:  289
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 Threonine (T) to Isoleucine (I) at position 289 (T289I, p.Thr289Ile).
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 (T) to medium size and hydrophobic (I)
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:  Smith-Lemli-Opitz syndrome (SLOS) [MIM:270400]: An autosomal recessive frequent inborn disorder of sterol metabolism with characteristic congenital malformations and mental retardation. Children with SLOS have elevated serum 7-dehydrocholesterol (7-DHC) levels and low serum cholesterol levels. SLOS occurs in relatively high frequency: approximately 1 in 20,000 to 30,000 births in populations of northern and central European background. Historically, a clinical distinction often was made between classic ('type I') SLOS and the more severely affected ('type II') patients. There is, in reality, a clinical and biochemical continuum from mild to severe SLOS. {ECO:0000269|PubMed:10677299, ECO:0000269|PubMed:10995508, ECO:0000269|PubMed:11175299, ECO:0000269|PubMed:11427181, ECO:0000269|PubMed:12949967, ECO:0000269|PubMed:15954111, ECO:0000269|PubMed:9653161, ECO:0000269|PubMed:9683613}. 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 SLOS.
Any additional useful information about the variant.

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



Sequence information

Variant position:  289
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  475
The length of the canonical sequence.

Location on the sequence:   AMVLVNVLQAIYVIDFFWNE  T WYLKTIDICHDHFGWYLGWG
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                         AMVLVNVLQAIYVIDFFWNETWYLKTIDICHDHFGWYLGWG

Mouse                         SMILVNVLQAIYVLDFFWNETWYLKTIDICHDHFGWYLGWG

Rat                           SMILVNVLQAIYVLDFFWNETWYLKTIDICHDHFGWYLGWG

Bovine                        SMVLVNILQAIYVLDFFWNETWYLKTIDICHDHFGWYLGWG

Xenopus laevis                SMILVNVLQAIYVVDFFWNESWYLKTIDICHDHFGWYLGWG

Xenopus tropicalis            SMILVNVLQAIYVVDFFWNESWYLKTIDICHDHFGWYLGWG

Zebrafish                     SMILVNVLQAVYVVDFFWNEAWYLKTIDICHDHFGWYLGWG

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 – 475 7-dehydrocholesterol reductase


Literature citations

Mutational spectrum in the Delta7-sterol reductase gene and genotype-phenotype correlation in 84 patients with Smith-Lemli-Opitz syndrome.
Witsch-Baumgartner M.; Fitzky B.U.; Ogorelkova M.; Kraft H.G.; Moebius F.F.; Glossmann H.; Seedorf U.; Gillessen-Kaesbach G.; Hoffmann G.F.; Clayton P.; Kelley R.I.; Utermann G.;
Am. J. Hum. Genet. 66:402-412(2000)
Cited for: VARIANTS SLOS SER-51; MET-93; PRO-99; HIS-107; PRO-109; ASP-147; MET-154; PRO-157; LEU-169; CYS-182; CYS-242; VAL-247; MET-281; ILE-289; GLY-311; TYR-311; HIS-324; LEU-326; GLN-352; TRP-352; ALA-353; CYS-362; TYR-380; ARG-380; SER-380; LEU-397; CYS-404; SER-404; HIS-408; SER-410; ARG-410; CYS-443; GLN-446; GLN-448; LYS-448 AND LEU-450;

Mutation analysis and description of sixteen RSH/Smith-Lemli-Opitz syndrome patients: polymerase chain reaction-based assays to simplify genotyping.
Krakowiak P.A.; Nwokoro N.A.; Wassif C.A.; Battaile K.P.; Nowaczyk M.J.M.; Connor W.E.; Maslen C.; Steiner R.D.; Porter F.D.;
Am. J. Med. Genet. 94:214-227(2000)
Cited for: VARIANT SLOS ILE-289;

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.