TBX20

Non syndromic associated CHDs overview

VSD (1, 20%)

Mitral valvar stenosis - congenital (1, 20%)

ASD (3, 60%)

[edit] Synopsys

Thus far, one study showed the presence of mutations in this gene in 2 families with a variety of heart defects: septal defects, and mitral valve defects as well as cardiomyopathies. This transcription factor is a member of the family of TATA-box binding proteins, and several members of this family have been implicated in heart development: mutations in TBX1 and TBX5 are associated with human (mostly syndromic) heart defects, while TBX2 and TBX3 have been implicated in heart development through studies in animal models.

External references for TBX20

• ensembl: ENSG00000164532
• OMIM: 606061
• Search miRBase for TBX20
• Expression patterns from 4DXPress: TBX20
• MGI: MGI:1888496
• ZFIN: ZDB-GENE-000427-7
• Wikipedia: TBX20
• Search Wikiproteins: TBX20
• Search Genetic Association Database: TBX20
• Search GeneTests: TBX20
• CHeartED:

Known phenotypes for TBX20

Non-syndromic

ASD

Support: confirmed: 2 or more independent reports > 1% incidence References: PMID:17668378 (population study with screening of similar CHD patients and normal controls ) PMID:19762328 (unspecified or mispecified ) Inheritence: autosomal dominant inheritance in 2 small families. Variable expression of mutations, 3 out 7 mutation carriers have an ASD. Incidence: Rare cause of ASD (Kirk EP et al., 2007). Comments: Studies: (2) [ show ] [ hide ] Reference: PMID:17668378 Incidence: 2/175 patients Comments: Mutations were found in two patients with a positive family history. A third patient carries a mutation that was absent from >300 normal controls. Although this patient had a positive familiy history, the mutation did not segregate with the phenotype, rendering it's causality obscure (Kirk EP et al., 2007). Reference: PMID:19762328 Incidence: 1/170 patients Comments: Posch MG et al. performed mutation analysis of the TBX20 gene in 170 patients with atrial septal defect type secundum. One heterozygous mutation was detected in a patient with an isolated atrial septal defect. The proband's sister and mother both showed a large patent foramen ovale and were positive for the mutation. Add another study.

Mitral valvar stenosis - congenital

Support: likely: 2 or more patients (with CHD and a mutation in the candidate gene) References: PMID:17668378 (population study with screening of similar CHD patients and normal controls ) Inheritence: autosomal dominant inheritance in 2 small families. Variable expression. Incidence: Comments: Studies: (1) [ show ] [ hide ] Reference: PMID:17668378 Incidence: 1/1 patients Comments: Mutations were found in 2 separate families with ASD, VSD, mitral valve disease and cardiomyopathy. In one family, a patient with a TBX20 mutation presented with mitral valve stenosis (Kirk EP et al., 2007). Add another study.

VSD

Support: unconfirmed: a single case report References: PMID:17668378 (population study with screening of similar CHD patients and normal controls ) Inheritence: autosomal dominant inheritance in 2 small families. Variable expression of mutations, 1 family member has a VSD. Incidence: Rare cause of VSD, since mutations were absent in 63 patients with VSD Comments: Studies: (1) [ show ] [ hide ] Reference: PMID:17668378 Incidence: 1/1 patients Comments: Mutations were found in 2 separate families with ASD, VSD, mitral valve disease and cardiomyopathy. In one family, a patient with a TBX20 mutation presented with VSD (Kirk EP et al., 2007). Add another study.

Add another phenotype.

Syndromic

Add another phenotype.

Protein interaction partners

Patients reports for TBX20

• case 1491 Clinical data Phenotype

Translocations

Add another translocation.

Mutations in TBX20

Mutation (DNA)	Mutation (peptide)	CHD	Reference	Other features	Inheritence	Additional info.
374C>G (NM_020417)	I121M	ASD	PMID:19762328	Isolated atrial septal defect type secundum	Dominant Familial	show hide Genetic evidence Segregating The proband's sister and mother both showed a large patent foramen ovale and were positive for the mutation. in silico prediction Two in silico tools (Polyphen and SIFT) predicted functional consequeces for the variant. Functional studies The affected residue lies in the T-box DNA-binding region and is highly conserved among species. Tertiary hydrophobic interactions within the mutant TBX20 T-box were significantly altered leading to a more dynamich structure of the protein. Moreover, Tbx20-I121M resulted in a significantly enhanced transcriptional activity. Comments These data suggest that human ASD type 2 may be related to loss-of-function as well as gain-of-function mutations in the TBX20 gene.
456C>G	I152M	ASD	PMID:17668378		Dominant Familial	show hide Genetic evidence Segregating in silico prediction Functional studies Comments
456C>G	I152M	ASD	PMID:17668378		Dominant Familial	show hide Genetic evidence Segregating in silico prediction Functional studies Comments
583C>T	Q195X	ASD	PMID:17668378		Dominant Familial	show hide Genetic evidence Segregating in silico prediction Functional studies Comments

Representation of protein TBX20

Heart expression domain of TBX20

No specified expression domain for TBX20

Add a new domain where gene TBX20 is expressed

Associated CHDs found by automated text mining

AGeneApart Method

• Totally anomalous pulmonary venous connection (04.08.05) (sig = 2.951)

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• Atrial septum defect (05.04.01) (sig = 2.162)

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• Tetralogy of Fallot (01.01.01) (sig = 1.953)

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Huge Navigator (Genopedia)

See complete results on Genopedia (including non CHD)

Heart defects

• 4-31 congenital anomalies of the heart

This page contributors

• Jeroen Breckpot - CME Leuven (Belgium) (association, study)