2-238848439-A-C

Position:

• chr2-238848439-A-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP3_Strong PP5

The NM_001271893.4(TWIST2):​c.224A>C​(p.Glu75Ala) variant causes a missense 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E75K) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: TWIST2 NM_001271893.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 8.88

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]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a domain bHLH (size 51) in uniprot entity TWST2_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_001271893.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr2-238848438-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 208077.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.981
• PP5: Variant 2-238848439-A-C is Pathogenic according to our data. Variant chr2-238848439-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 208076.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TWIST2	NM_001271893.4	c.224A>C	p.Glu75Ala	missense_variant	1/2	ENST00000612363.2
TWIST2	NM_057179.3	c.224A>C	p.Glu75Ala	missense_variant	1/2
TWIST2	XR_007069137.1	n.355A>C		non_coding_transcript_exon_variant	1/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TWIST2	ENST00000612363.2	c.224A>C	p.Glu75Ala	missense_variant	1/2	1	NM_001271893.4	P1
TWIST2	ENST00000448943.2	c.224A>C	p.Glu75Ala	missense_variant	1/2	1		P1
TWIST2	ENST00000710607.1	c.224A>C	p.Glu75Ala	missense_variant	1/2			P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Barber-Say syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Jul 02, 2015

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	34
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.96	D;D
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.98	D;D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Pathogenic	4.1	H;H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-5.9	D;.
REVEL	Pathogenic	0.99
Sift	Uncertain	0.0010	D;.
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.95
MutPred		0.85		Gain of MoRF binding (P = 0.0559);Gain of MoRF binding (P = 0.0559);
MVP		0.95
MPC		3.0
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.92
gMVP		0.99

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

LitVar

Other links and lift over

dbSNP: rs1553565143; hg19: chr2-239757080;