7-19116735-C-T

Variant names:

• chr7-19116735-C-T
• NM_000474.4:c.587G>A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_000474.4(TWIST1):​c.587G>A​(p.Trp196*) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: TWIST1 NM_000474.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.64

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0361 CDS is truncated, and there are 1 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-19116735-C-T is Pathogenic according to our data. Variant chr7-19116735-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 1075291.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TWIST1	NM_000474.4	c.587G>A	p.Trp196*	stop_gained	Exon 1 of 2	ENST00000242261.6	NP_000465.1
TWIST1	NR_149001.2	n.902G>A		non_coding_transcript_exon_variant	Exon 1 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TWIST1	ENST00000242261.6	c.587G>A	p.Trp196*	stop_gained	Exon 1 of 2	1	NM_000474.4	ENSP00000242261.5
TWIST1	ENST00000354571.5	n.383G>A		non_coding_transcript_exon_variant	Exon 1 of 3	2		ENSP00000346582.5
TWIST1	ENST00000443687.5	n.188G>A		non_coding_transcript_exon_variant	Exon 1 of 4	4		ENSP00000416986.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Saethre-Chotzen syndrome;C4551902:TWIST1-related craniosynostosis Pathogenic:1

Jun 05, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. Loss-of-function variants in TWIST1 are known to be pathogenic (PMID: 10749989). This variant has been observed in individual(s) with craniosynostosis (Invitae). This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Trp196*) in the TWIST1 gene. It is expected to result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	42
DANN	Uncertain	0.99
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
Vest4		0.88
GERP RS		4.3

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr7-19156358;