chr7-19116946-C-A

Variant names:

• chr7-19116946-C-A
• rs121909188
• NM_000474.4:c.376G>T

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000474.4(TWIST1):​c.376G>T​(p.Glu126*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,600 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TWIST1 NM_000474.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.77
• Publications: 6 publications found

Genes affected

TWIST1 (HGNC:12428): (twist family bHLH transcription factor 1) This gene encodes a basic helix-loop-helix (bHLH) transcription factor that plays an important role in embryonic development. The encoded protein forms both homodimers and heterodimers that bind to DNA E box sequences and regulate the transcription of genes involved in cranial suture closure during skull development. This protein may also regulate neural tube closure, limb development and brown fat metabolism. This gene is hypermethylated and overexpressed in multiple human cancers, and the encoded protein promotes tumor cell invasion and metastasis, as well as metastatic recurrence. Mutations in this gene cause Saethre-Chotzen syndrome in human patients, which is characterized by craniosynostosis, ptosis and hypertelorism. [provided by RefSeq, Jul 2020]

TWIST1 Gene-Disease associations (from GenCC):

• Saethre-Chotzen syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P, Orphanet, Laboratory for Molecular Medicine
• TWIST1-related craniosynostosis

  Inheritance: AD Classification: STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, ClinGen
• isolated brachycephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated plagiocephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• isolated scaphocephaly

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Sweeney-Cox syndrome

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-19116946-C-A is Pathogenic according to our data. Variant chr7-19116946-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 7977.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000474.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TWIST1	NM_000474.4	MANE Select	c.376G>T	p.Glu126*	stop_gained	Exon 1 of 2	NP_000465.1	Q15672
	TWIST1	NR_149001.2		n.691G>T		non_coding_transcript_exon	Exon 1 of 3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TWIST1	ENST00000242261.6	TSL:1 MANE Select	c.376G>T	p.Glu126*	stop_gained	Exon 1 of 2	ENSP00000242261.5	Q15672
	TWIST1	ENST00000354571.5	TSL:2	n.172G>T		non_coding_transcript_exon	Exon 1 of 3	ENSP00000346582.5	H7BY00
	TWIST1	ENST00000443687.5	TSL:4	n.-24G>T		upstream_gene	N/A	ENSP00000416986.1	H7C4D7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461600 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727128

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26118

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53230

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111958

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	Saethre-Chotzen syndrome (2)
1	-	-	not provided (1)
1	-	-	Saethre-Chotzen syndrome;C4551902:TWIST1-related craniosynostosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	45
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.97	D
PhyloP100		7.8
Vest4		0.93
GERP RS		4.7
Mutation Taster		=1/199	disease causing (ClinVar)

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: rs121909188; hg19: chr7-19156569;