18-47848538-A-T

Variant names:

• chr18-47848538-A-T
• rs2144299833
• NM_005901.6:c.934T>A
• SMAD2 p.Cys312Ser

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PS1 PM2 PP2 PP3_Strong

The NM_005901.6(SMAD2):​c.934T>A​(p.Cys312Ser) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SMAD2 NM_005901.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.32
• Publications: 0 publications found

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]

SMAD2 Gene-Disease associations (from GenCC):

• congenital heart disease

  Inheritance: AD Classification: DEFINITIVE, MODERATE Submitted by: Ambry Genetics, ClinGen
• Loeys-Dietz syndrome 6

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen
• congenital heart defects, multiple types, 8, with or without heterotaxy

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: PanelApp Australia, Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• Loeys-Dietz syndrome

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• familial thoracic aortic aneurysm and aortic dissection

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PS1: Transcript NM_005901.6 (SMAD2) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• 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 congenital heart disease, Loeys-Dietz syndrome 6, congenital heart defects, multiple types, 8, with or without heterotaxy, familial thoracic aortic aneurysm and aortic dissection, Loeys-Dietz syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005901.6. 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
	SMAD2	NM_005901.6	MANE Select	c.934T>A	p.Cys312Ser	missense	Exon 8 of 11	NP_005892.1	Q15796-1
	SMAD2	NM_001003652.4		c.934T>A	p.Cys312Ser	missense	Exon 8 of 11	NP_001003652.1	Q15796-1
	SMAD2	NM_001135937.3		c.844T>A	p.Cys282Ser	missense	Exon 7 of 10	NP_001129409.1	Q15796-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMAD2	ENST00000262160.11	TSL:1 MANE Select	c.934T>A	p.Cys312Ser	missense	Exon 8 of 11	ENSP00000262160.6	Q15796-1
	SMAD2	ENST00000402690.6	TSL:1	c.934T>A	p.Cys312Ser	missense	Exon 8 of 11	ENSP00000384449.1	Q15796-1
	SMAD2	ENST00000356825.8	TSL:1	c.844T>A	p.Cys282Ser	missense	Exon 7 of 10	ENSP00000349282.4	Q15796-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461774 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727200

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111934

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D
Eigen	Pathogenic	0.77
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.20	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.1	M
PhyloP100		9.3
PrimateAI	Pathogenic	0.90	D
PROVEAN	Pathogenic	-9.8	D
REVEL	Pathogenic	0.83
Sift	Benign	0.080	T
Sift4G	Benign	0.11	T
Varity_R		0.89
gMVP		0.98
Mutation Taster		=5/95	disease causing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs2144299833;

hg19: chr18-45374909;