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UniProtKB/Swiss-Prot Q08357: Variant p.Asp28Asn

Sodium-dependent phosphate transporter 2
Gene: SLC20A2
Variant information

Variant position:  28
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 Aspartate (D) to Asparagine (N) at position 28 (D28N, p.Asp28Asn).
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 acidic (D) to medium size and polar (N)
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:  Basal ganglia calcification, idiopathic, 1 (IBGC1) [MIM:213600]: A form of basal ganglia calcification, an autosomal dominant condition characterized by symmetric calcification in the basal ganglia and other brain regions. Affected individuals can either be asymptomatic or show a wide spectrum of neuropsychiatric symptoms, including parkinsonism, dystonia, tremor, ataxia, dementia, psychosis, seizures, and chronic headache. Serum levels of calcium, phosphate, alkaline phosphatase and parathyroid hormone are normal. The neuropathological hallmark of the disease is vascular and pericapillary calcification, mainly of calcium phosphate, in the affected brain areas. {ECO:0000269|PubMed:15955065, ECO:0000269|PubMed:22327515, ECO:0000269|PubMed:23334463, ECO:0000269|PubMed:23406454, ECO:0000269|PubMed:23939468, ECO:0000269|PubMed:24065723, ECO:0000269|PubMed:24463626, ECO:0000269|PubMed:25284758}. 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 IBGC1; Impairs phosphate transport; no effect on retroviral receptor function.
Any additional useful information about the variant.

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



Sequence information

Variant position:  28
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  652
The length of the canonical sequence.

Location on the sequence:   WMVILGFIIAFILAFSVGAN  D VANSFGTAVGSGVVTLRQAC
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                         WMVILGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

Mouse                         WMVILGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

Rat                           WMVILGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

Bovine                        WMVILGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

Cat                           WMVILGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

Xenopus laevis                WMVIVGFIIAFVLAFSVGANDVANSFGTAVGSGVVTLRQAC

Xenopus tropicalis            WMVIVGFIIAFILAFSVGANDVANSFGTAVGSGVVTLRQAC

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 – 652 Sodium-dependent phosphate transporter 2
Topological domain 27 – 46 Cytoplasmic


Literature citations

Evolutionary and experimental analyses of inorganic phosphate transporter PiT family reveals two related signature sequences harboring highly conserved aspartic acids critical for sodium-dependent phosphate transport function of human PiT2.
Boettger P.; Pedersen L.;
FEBS J. 272:3060-3074(2005)
Cited for: FUNCTION AS SODIUM-PHOSPHATE SYMPORTER; SUBUNIT; MUTAGENESIS OF ASP-506; CHARACTERIZATION OF VARIANT IBGC1 ASN-28;

Novel SLC20A2 mutations identified in southern Chinese patients with idiopathic basal ganglia calcification.
Chen W.J.; Yao X.P.; Zhang Q.J.; Ni W.; He J.; Li H.F.; Liu X.Y.; Zhao G.X.; Murong S.X.; Wang N.; Wu Z.Y.;
Gene 529:159-162(2013)
Cited for: VARIANTS IBGC1 LEU-11; ASN-28 AND PRO-62;

Phenotypic spectrum of probable and genetically-confirmed idiopathic basal ganglia calcification.
Nicolas G.; Pottier C.; Charbonnier C.; Guyant-Marechal L.; Le Ber I.; Pariente J.; Labauge P.; Ayrignac X.; Defebvre L.; Maltete D.; Martinaud O.; Lefaucheur R.; Guillin O.; Wallon D.; Chaumette B.; Rondepierre P.; Derache N.; Fromager G.; Schaeffer S.; Krystkowiak P.; Verny C.; Jurici S.; Sauvee M.; Verin M.; Lebouvier T.; Rouaud O.; Thauvin-Robinet C.; Rousseau S.; Rovelet-Lecrux A.; Frebourg T.; Campion D.; Hannequin D.;
Brain 136:3395-3407(2013)
Cited for: VARIANTS IBGC1 ASN-28; LEU-184; SER-194 AND SER-571;

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.