18-47841846-C-T

Variant names:

• chr18-47841846-C-T
• rs773849578
• NM_005901.6:c.1385G>A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_005901.6(SMAD2):​c.1385G>A​(p.Arg462His) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,190 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SMAD2 NM_005901.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.13

Genes affected

SMAD2 (HGNC:6768): (SMAD family member 2) The protein encoded by this gene belongs to the SMAD, a family of proteins similar to the gene products of the Drosophila gene 'mothers against decapentaplegic' (Mad) and the C. elegans gene Sma. SMAD proteins are signal transducers and transcriptional modulators that mediate multiple signaling pathways. This protein mediates the signal of the transforming growth factor (TGF)-beta, and thus regulates multiple cellular processes, such as cell proliferation, apoptosis, and differentiation. This protein is recruited to the TGF-beta receptors through its interaction with the SMAD anchor for receptor activation (SARA) protein. In response to TGF-beta signal, this protein is phosphorylated by the TGF-beta receptors. The phosphorylation induces the dissociation of this protein with SARA and the association with the family member SMAD4. The association with SMAD4 is important for the translocation of this protein into the nucleus, where it binds to target promoters and forms a transcription repressor complex with other cofactors. This protein can also be phosphorylated by activin type 1 receptor kinase, and mediates the signal from the activin. Alternatively spliced transcript variants have been observed for this gene. [provided by RefSeq, May 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a domain MH2 (size 193) in uniprot entity SMAD2_HUMAN there are 8 pathogenic changes around while only 0 benign (100%) in NM_005901.6
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the SMAD2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 11 curated pathogenic missense variants (we use a threshold of 10). The gene has 2 curated benign missense variants. Gene score misZ: 3.6626 (above the threshold of 3.09). Trascript score misZ: 4.4705 (above the threshold of 3.09). GenCC associations: The gene is linked to Loeys-Dietz syndrome 6, congenital heart disease, familial thoracic aortic aneurysm and aortic dissection, Loeys-Dietz syndrome, congenital heart defects, multiple types, 8, with or without heterotaxy.
• BP4: Computational evidence support a benign effect (MetaRNN=0.22339046).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMAD2	NM_005901.6	c.1385G>A	p.Arg462His	missense_variant	Exon 11 of 11	ENST00000262160.11	NP_005892.1
SMAD2	NM_001003652.4	c.1385G>A	p.Arg462His	missense_variant	Exon 11 of 11		NP_001003652.1
SMAD2	NM_001135937.3	c.1295G>A	p.Arg432His	missense_variant	Exon 10 of 10		NP_001129409.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMAD2	ENST00000262160.11	c.1385G>A	p.Arg462His	missense_variant	Exon 11 of 11	1	NM_005901.6	ENSP00000262160.6
SMAD2	ENST00000402690.6	c.1385G>A	p.Arg462His	missense_variant	Exon 11 of 11	1		ENSP00000384449.1
SMAD2	ENST00000356825.8	c.1295G>A	p.Arg432His	missense_variant	Exon 10 of 10	1		ENSP00000349282.4
SMAD2	ENST00000586040.5	c.1295G>A	p.Arg432His	missense_variant	Exon 9 of 9	5		ENSP00000466193.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152190 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74346

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000654

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Aug 15, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Uncertain	0.12	D
BayesDel_noAF	Uncertain	-0.060
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D;D;.;.
Eigen	Benign	-0.016
Eigen_PC	Benign	0.17
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	.;D;D;.
M_CAP	Benign	0.028	D
MetaRNN	Benign	0.22	T;T;T;T
MetaSVM	Uncertain	0.12	D
MutationAssessor	Benign	1.4	L;L;.;.
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.59	N;N;N;.
REVEL	Benign	0.26
Sift	Benign	0.051	T;T;D;.
Sift4G	Benign	0.11	T;T;T;T
Polyphen		0.0030	B;B;B;B
Vest4		0.35
MutPred		0.34		Loss of phosphorylation at S464 (P = 0.0632);Loss of phosphorylation at S464 (P = 0.0632);.;.;
MVP		0.85
MPC		1.3
ClinPred		0.81	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.46
gMVP		0.83

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: rs773849578; hg19: chr18-45368217;