rs1554881901

chr10-110573740-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_005445.4(SMC3):c.125T>C(p.Phe42Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMC3 NM_005445.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.00

Genes affected

SMC3 (HGNC:2468): (structural maintenance of chromosomes 3) This gene belongs to the SMC3 subfamily of SMC proteins. The encoded protein occurs in certain cell types as either an intracellular, nuclear protein or a secreted protein. The nuclear form, known as structural maintenance of chromosomes 3, is a component of the multimeric cohesin complex that holds together sister chromatids during mitosis, enabling proper chromosome segregation. Post-translational modification of the encoded protein by the addition of chondroitin sulfate chains gives rise to the secreted proteoglycan bamacan, an abundant basement membrane protein. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, SMC3
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.915

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SMC3	NM_005445.4	c.125T>C	p.Phe42Ser	missense_variant	3/29	ENST00000361804.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SMC3	ENST00000361804.5	c.125T>C	p.Phe42Ser	missense_variant	3/29	1	NM_005445.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 26

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cornelia de Lange syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 15, 2016

In summary, this variant is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a SMC3-related disease. This sequence change replaces phenylalanine with serine at codon 42 of the SMC3 protein (p.Phe42Ser). The phenylalanine residue is highly conserved and there is a large physicochemical difference between phenylalanine and serine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.45
Cadd	Pathogenic	30
Dann	Uncertain	1.0
DEOGEN2	Benign	0.41	T
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.33	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Pathogenic	0.84	D
MutationAssessor	Pathogenic	3.4	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-7.0	D
REVEL	Pathogenic	0.84
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.83
MutPred		0.71		Gain of disorder (P = 0.0133);
MVP		0.96
MPC		4.9
ClinPred		1.0	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1554881901; hg19: chr10-112333498;