18-9359992-G-T

Variant names:

• chr18-9359992-G-T
• rs142770364
• NM_020648.6:c.144G>T

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_020648.6(TWSG1):​c.144G>T​(p.Pro48Pro) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,968 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. P48P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TWSG1 NM_020648.6 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.971
• Publications: 3 publications found

Genes affected

TWSG1 (HGNC:12429): (twisted gastrulation BMP signaling modulator 1) Enables transforming growth factor beta binding activity. Involved in several processes, including negative regulation of CD4-positive, alpha-beta T cell proliferation; positive regulation of pathway-restricted SMAD protein phosphorylation; and transforming growth factor beta receptor signaling pathway. Predicted to be located in extracellular region. Predicted to be active in extracellular space. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP7: Synonymous conserved (PhyloP=-0.971 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_020648.6. 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
	TWSG1	NM_020648.6	MANE Select	c.144G>T	p.Pro48Pro	synonymous	Exon 3 of 5	NP_065699.1	Q9GZX9-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TWSG1	ENST00000262120.10	TSL:1 MANE Select	c.144G>T	p.Pro48Pro	synonymous	Exon 3 of 5	ENSP00000262120.5	Q9GZX9-1
	TWSG1	ENST00000951397.1		c.144G>T	p.Pro48Pro	synonymous	Exon 3 of 6	ENSP00000621456.1
	TWSG1	ENST00000934387.1		c.144G>T	p.Pro48Pro	synonymous	Exon 3 of 5	ENSP00000604446.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251324 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: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460968 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726796

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

African (AFR) AF: 0.00 AC: 0 AN: 33464

American (AMR) AF: 0.00 AC: 0 AN: 44710

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.0000504 AC: 2 AN: 39658

South Asian (SAS) AF: 0.00 AC: 0 AN: 86174

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53332

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111426

Other (OTH) AF: 0.00 AC: 0 AN: 60328

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	1.2
DANN	Benign	0.46
PhyloP100		-0.97
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs142770364; hg19: chr18-9359990;