rs199809905

Positions:

• chr18-51054933-C-A
• chr18-51054933-C-G
• chr18-51054933-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_005359.6(SMAD4):​c.607C>A​(p.Pro203Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,272 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P203A) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: SMAD4 NM_005359.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.46

Genes affected

SMAD4 (HGNC:6770): (SMAD family member 4) This gene encodes a member of the Smad family of signal transduction proteins. Smad proteins are phosphorylated and activated by transmembrane serine-threonine receptor kinases in response to transforming growth factor (TGF)-beta signaling. The product of this gene forms homomeric complexes and heteromeric complexes with other activated Smad proteins, which then accumulate in the nucleus and regulate the transcription of target genes. This protein binds to DNA and recognizes an 8-bp palindromic sequence (GTCTAGAC) called the Smad-binding element (SBE). The protein acts as a tumor suppressor and inhibits epithelial cell proliferation. It may also have an inhibitory effect on tumors by reducing angiogenesis and increasing blood vessel hyperpermeability. The encoded protein is a crucial component of the bone morphogenetic protein signaling pathway. The Smad proteins are subject to complex regulation by post-translational modifications. Mutations or deletions in this gene have been shown to result in pancreatic cancer, juvenile polyposis syndrome, and hereditary hemorrhagic telangiectasia syndrome. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SMAD4

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMAD4	NM_005359.6	c.607C>A	p.Pro203Thr	missense_variant	5/12	ENST00000342988.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMAD4	ENST00000342988.8	c.607C>A	p.Pro203Thr	missense_variant	5/12	5	NM_005359.6	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152154 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

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

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251488 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135920

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152272 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74452

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.000193

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.074
BayesDel_addAF	Pathogenic	0.19	D
BayesDel_noAF	Pathogenic	0.20
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D;D;T
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Benign	0.046	D
MetaRNN	Uncertain	0.57	D;D;D
MetaSVM	Benign	-0.48	T
MutationAssessor	Benign	1.9	L;L;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-3.4	D;D;.
REVEL	Uncertain	0.32
Sift	Uncertain	0.0070	D;D;.
Sift4G	Uncertain	0.0080	D;D;D
Polyphen		0.43	B;B;.
Vest4		0.63
MVP		0.96
MPC		0.55
ClinPred		0.55	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.32
gMVP		0.59

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: rs199809905; hg19: chr18-48581303;