22-19765921-G-T

Variant names:

• chr22-19765921-G-T
• rs41298838
• NM_001379200.1:c.955G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP6_Moderate

The NM_001379200.1(TBX1):​c.955G>T​(p.Gly319Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000000723 in 1,383,434 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely benign (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G319A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: TBX1 NM_001379200.1 missense
• Clinical Significance: Likely benign criteria provided, single submitter U:1 B:1
• Conservation: PhyloP100: 5.03
• Publications: 29 publications found

Genes affected

TBX1 (HGNC:11592): (T-box transcription factor 1) This gene is a member of a phylogenetically conserved family of genes that share a common DNA-binding domain, the T-box. T-box genes encode transcription factors involved in the regulation of developmental processes. This gene product shares 98% amino acid sequence identity with the mouse ortholog. DiGeorge syndrome (DGS)/velocardiofacial syndrome (VCFS), a common congenital disorder characterized by neural-crest-related developmental defects, has been associated with deletions of chromosome 22q11.2, where this gene has been mapped. Studies using mouse models of DiGeorge syndrome suggest a major role for this gene in the molecular etiology of DGS/VCFS. Several alternatively spliced transcript variants encoding different isoforms have been described for this gene. [provided by RefSeq, Jul 2008]

TBX1 Gene-Disease associations (from GenCC):

• conotruncal heart malformations

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• DiGeorge syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• velocardiofacial syndrome

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics
• 22q11.2 deletion syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP6: Variant 22-19765921-G-T is Benign according to our data. Variant chr22-19765921-G-T is described in ClinVar as Likely_benign. ClinVar VariationId is 455794.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBX1	NM_001379200.1	c.955G>T	p.Gly319Cys	missense_variant	Exon 6 of 7	ENST00000649276.2	NP_001366129.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBX1	ENST00000649276.2	c.955G>T	p.Gly319Cys	missense_variant	Exon 6 of 7		NM_001379200.1	ENSP00000497003.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.23e-7 AC: 1 AN: 1383434 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 682132

African (AFR) AF: 0.00 AC: 0 AN: 30444

American (AMR) AF: 0.00 AC: 0 AN: 34576

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24642

East Asian (EAS) AF: 0.00 AC: 0 AN: 34058

South Asian (SAS) AF: 0.00 AC: 0 AN: 78166

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 45450

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5114

European-Non Finnish (NFE) AF: 9.31e-7 AC: 1 AN: 1073748

Other (OTH) AF: 0.00 AC: 0 AN: 57236

GnomAD4 genome Cov.: 33

Alfa AF: 0.0000253 Hom.: 1

Bravo AF: 0.00000756

ClinVar

Significance: Likely benign

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

TBX1-related disorder Uncertain:1

Jan 05, 2024

PreventionGenetics, part of Exact Sciences

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

The TBX1 c.928G>T variant is predicted to result in the amino acid substitution p.Gly310Cys. To our knowledge, this variant has not been reported in the literature. This variant is reported in 0.0065% of alleles in individuals of European (Non-Finnish) descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

DiGeorge syndrome Benign:1

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.060
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.54	.;D;.;.
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.84	T;T;T;T
M_CAP	Pathogenic	0.90	D
MetaRNN	Uncertain	0.72	D;D;D;D
MetaSVM	Uncertain	0.47	D
MutationAssessor	Benign	0.90	L;L;L;.
PhyloP100		5.0
PrimateAI	Pathogenic	0.80	T
PROVEAN	Benign	-1.9	N;N;N;.
REVEL	Uncertain	0.62
Sift	Uncertain	0.0010	D;D;D;.
Sift4G	Uncertain	0.010	D;D;D;.
Polyphen		1.0	.;D;.;.
Vest4		0.59
MutPred		0.40		Gain of catalytic residue at P309 (P = 0.0135);Gain of catalytic residue at P309 (P = 0.0135);Gain of catalytic residue at P309 (P = 0.0135);.;
MVP		0.62
MPC		1.5
ClinPred		0.91	D
GERP RS		3.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.18
gMVP		0.55
Mutation Taster		=51/49	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs41298838; hg19: chr22-19753444;