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UniProtKB/Swiss-Prot Q9UMR3: Variant p.Ile121Met

T-box transcription factor TBX20
Gene: TBX20
Chromosomal location: 7p14-p15
Variant information

Variant position:  121
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 Isoleucine (I) to Methionine (M) at position 121 (I121M, p.Ile121Met).
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:  Similar physico-chemical property. Both residues are medium size and hydrophobic.
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:  Atrial septal defect 4 (ASD4) [MIM:611363]: A congenital heart malformation characterized by incomplete closure of the wall between the atria resulting in blood flow from the left to the right atria. Patients show other heart abnormalities including defects in septation, chamber growth and valvulogenesis. The disease is not associated with defects in the cardiac conduction system or with non-cardiac abnormalities. {ECO:0000269|PubMed:17668378, ECO:0000269|PubMed:19762328}. 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 ASD4; significant gain of function in sequence-specific DNA binding transcription factor activity; gain of function in sequence-specific DNA binding transcription factor activity in the presence of cotranscription factors NKX2-5 and GATA4 or GATA5.
Any additional useful information about the variant.

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



Sequence information

Variant position:  121
The position of the amino-acid change on the UniProtKB canonical protein sequence.

Protein sequence length:  447
The length of the canonical sequence.

Location on the sequence:   ACSLETKELWDKFHELGTEM  I ITKSGRRMFPTIRVSFSGVD
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                         ACSLETKELWDKFHELGTEMIITKSGRRMFPTIRVSFSGVD

Mouse                         ACSLETKELWDKFHELGTEMIITKSGRRMFPTIRVSFSGVD

Chicken                       SCSLETKELWDKFHELGTEMIITKSGRRMFPTIRVSFSGVD

Xenopus laevis                SCSLETKELWDKFHDLGTEMIITKSGRRMFPTIRVSFSGVD

Xenopus tropicalis            SCSLETKELWDKFHDLGTEMIITKSGRRMFPTIRVSFSGVD

Zebrafish                     SCSLETKELWDKFHELGTEMIITKSGRRMFPTIRVSFSGVD

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 – 447 T-box transcription factor TBX20
DNA binding 109 – 288 T-box


Literature citations

A gain-of-function TBX20 mutation causes congenital atrial septal defects, patent foramen ovale and cardiac valve defects.
Posch M.G.; Gramlich M.; Sunde M.; Schmitt K.R.; Lee S.H.; Richter S.; Kersten A.; Perrot A.; Panek A.N.; Al Khatib I.H.; Nemer G.; Megarbane A.; Dietz R.; Stiller B.; Berger F.; Harvey R.P.; Ozcelik C.;
J. Med. Genet. 47:230-235(2010)
Cited for: VARIANTS ASD4 MET-121 AND MET-152; CHARACTERIZATION OF VARIANTS ASD4 MET-121 AND MET-152;

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.