4-145553802-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PP2 PP3

The NM_005900.3(SMAD1):c.1016T>G(p.Val339Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,636 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: SMAD1 NM_005900.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.02

Genes affected

SMAD1 (HGNC:6767): (SMAD family member 1) 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 signals of the bone morphogenetic proteins (BMPs), which are involved in a range of biological activities including cell growth, apoptosis, morphogenesis, development and immune responses. In response to BMP ligands, this protein can be phosphorylated and activated by the BMP receptor kinase. The phosphorylated form of this protein forms a complex with SMAD4, which is important for its function in the transcription regulation. This protein is a target for SMAD-specific E3 ubiquitin ligases, such as SMURF1 and SMURF2, and undergoes ubiquitination and proteasome-mediated degradation. Alternatively spliced transcript variants encoding the same protein have been observed. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PP2: Missense variant where missense usually causes diseases, SMAD1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.786

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMAD1	NM_005900.3	c.1016T>G	p.Val339Gly	missense_variant	6/7	ENST00000302085.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMAD1	ENST00000302085.9	c.1016T>G	p.Val339Gly	missense_variant	6/7	1	NM_005900.3	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251106 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135704

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461636 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727154

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 24, 2023

The c.1016T>G (p.V339G) alteration is located in exon 6 (coding exon 5) of the SMAD1 gene. This alteration results from a T to G substitution at nucleotide position 1016, causing the valine (V) at amino acid position 339 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.35
Cadd	Pathogenic	28
Dann	Benign	0.95
DEOGEN2	Pathogenic	0.97	D;D;D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.40
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.79	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.6	M;M;M
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-6.5	D;D;D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;D;D
Sift4G	Benign	0.40	T;T;T
Polyphen		0.88	P;P;P
Vest4		0.67
MutPred		0.53		Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);Loss of stability (P = 0.0036);
MVP		0.95
MPC		2.4
ClinPred		0.98	D
GERP RS		5.8
Varity_R		0.95
gMVP		0.79

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: rs1168211211; hg19: chr4-146474954;