chr2-238848379-GC-G

Variant names:

• chr2-238848379-GC-G
• rs1574742341
• NM_001271893.4:c.168delC

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_001271893.4(TWIST2):​c.168delC​(p.Ser57AlafsTer45) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TWIST2 NM_001271893.4 frameshift
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 1.36
• Publications: 2 publications found

Genes affected

TWIST2 (HGNC:20670): (twist family bHLH transcription factor 2) The protein encoded by this gene is a basic helix-loop-helix type transcription factor and shares similarity with Twist. This protein may inhibit osteoblast maturation and maintain cells in a preosteoblast phenotype during osteoblast development. This gene may be upregulated in certain cancers. Mutations in this gene cause focal facial dermal dysplasia 3, Setleis type. Two transcript variants encoding the same protein have been found. [provided by RefSeq, Apr 2014]

TWIST2 Gene-Disease associations (from GenCC):

• ablepharon macrostomia syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet
• Barber-Say syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• focal facial dermal dysplasia type III

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: G2P, Labcorp Genetics (formerly Invitae), Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 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 2-238848379-GC-G is Pathogenic according to our data. Variant chr2-238848379-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 39840.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001271893.4. 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
	TWIST2	NM_001271893.4	MANE Select	c.168delC	p.Ser57AlafsTer45	frameshift	Exon 1 of 2	NP_001258822.1	Q8WVJ9
	TWIST2	NM_057179.3		c.168delC	p.Ser57AlafsTer45	frameshift	Exon 1 of 2	NP_476527.1	Q8WVJ9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TWIST2	ENST00000612363.2	TSL:1 MANE Select	c.168delC	p.Ser57AlafsTer45	frameshift	Exon 1 of 2	ENSP00000482581.1	Q8WVJ9
	TWIST2	ENST00000448943.2	TSL:1	c.168delC	p.Ser57AlafsTer45	frameshift	Exon 1 of 2	ENSP00000405176.2	Q8WVJ9
	TWIST2	ENST00000710607.1		c.168delC	p.Ser57AlafsTer45	frameshift	Exon 1 of 2	ENSP00000518373.1	Q8WVJ9

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Focal facial dermal dysplasia type III (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		1.4
Mutation Taster		=6/194	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: rs1574742341; hg19: chr2-239757020;