16-30088756-G-GC

Variant names:

• chr16-30088756-G-GC
• rs758051786
• NM_004608.4:c.704dupG

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PP5_Moderate

The NM_004608.4(TBX6):​c.704dupG​(p.Met236HisfsTer44) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,644 control chromosomes in the GnomAD database, with no homozygous occurrence. There is a variant allele frequency bias in the population database for this variant (GnomAdExome4), which may indicate mosaicism or somatic mutations in the reference population data. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: TBX6 NM_004608.4 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.578
• Publications: 6 publications found

Genes affected

TBX6 (HGNC:11605): (T-box transcription factor 6) 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. Knockout studies in mice indicate that this gene is important for specification of paraxial mesoderm structures. [provided by RefSeq, Aug 2008]

TBX6 Gene-Disease associations (from GenCC):

• spondylocostal dysostosis 5

  Inheritance: Unknown, SD Classification: MODERATE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• autosomal dominant spondylocostal dysostosis

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital anomaly of kidney and urinary tract

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 16-30088756-G-GC is Pathogenic according to our data. Variant chr16-30088756-G-GC is described in ClinVar as Pathogenic. ClinVar VariationId is 243053.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004608.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TBX6	NM_004608.4	MANE Select	c.704dupG	p.Met236HisfsTer44	frameshift	Exon 5 of 9	NP_004599.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TBX6	ENST00000395224.7	TSL:1 MANE Select	c.704dupG	p.Met236HisfsTer44	frameshift	Exon 5 of 9	ENSP00000378650.2
	TBX6	ENST00000279386.6	TSL:1	c.704dupG	p.Met236HisfsTer44	frameshift	Exon 4 of 8	ENSP00000279386.2
	TBX6	ENST00000553607.1	TSL:1	c.704dupG	p.Met236HisfsTer44	frameshift	Exon 4 of 5	ENSP00000461223.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00 AC: 0 AN: 250890 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461644 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727102

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.0000375 AC: 2 AN: 53284

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111920

Other (OTH) AF: 0.00 AC: 0 AN: 60374

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00367175), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Spondylocostal dysostosis 5 Pathogenic:1

Nov 15, 2015

Lupski Lab, Baylor-Hopkins CMG, Baylor College of Medicine

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

This variant was observed in 1 individual with a vertebral malformation and rib abnormalities. The variant was found to be in trans with a high-risk TBX6 haplotype, T-C-A (rs2289292, rs3809624, rs3809627).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.58
Mutation Taster		=4/196	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs758051786; hg19: chr16-30100077; COSMIC: COSV54221972; COSMIC: COSV54221972;