chr22-19759559-G-T

Variant names:

• chr22-19759559-G-T
• rs737868
• ENST00000332710.8:c.-85G>T

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_Strong BS2

The ENST00000332710.8(TBX1):​c.-85G>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000913 in 1,424,374 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 36)
  • Exomes 𝑓: 0.0000091 (0 hom.)
• Consequence: TBX1 ENST00000332710.8 5_prime_UTR_premature_start_codon_gain
• Scores: Splicing: ADA: 0.00002500
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.611
• Publications: 20 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: Benign. The variant received -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.7).
• BS2: High AC in GnomAdExome4 at 13 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TBX1	NM_080647.1	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 9		NP_542378.1
TBX1	NM_080646.2	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 9		NP_542377.1
TBX1	NM_005992.1	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 10		NP_005983.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TBX1	ENST00000332710.8	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 9	1		ENSP00000331791.4
TBX1	ENST00000329705.11	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 9	1		ENSP00000331176.7
TBX1	ENST00000359500.7	c.-85G>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 2 of 10	1		ENSP00000352483.3

Frequencies

GnomAD3 genomes Cov.: 36

GnomAD4 exome AF: 0.00000913 AC: 13 AN: 1424374 Hom.: 0 Cov.: 54 AF XY: 0.00000849 AC XY: 6 AN XY: 706380

African (AFR) AF: 0.00 AC: 0 AN: 32442

American (AMR) AF: 0.00 AC: 0 AN: 40276

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25550

East Asian (EAS) AF: 0.00 AC: 0 AN: 37150

South Asian (SAS) AF: 0.00 AC: 0 AN: 82148

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 44896

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5622

European-Non Finnish (NFE) AF: 0.0000118 AC: 13 AN: 1097180

Other (OTH) AF: 0.00 AC: 0 AN: 59110

GnomAD4 genome Cov.: 36

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.70
CADD	Benign	4.3
DANN	Benign	0.69
PhyloP100		-0.61

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000025
dbscSNV1_RF	Benign	0.17
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: rs737868; hg19: chr22-19747082;