rs797045070

Positions:

• chr10-110581962-T-C

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_005445.4(SMC3):​c.587T>C​(p.Ile196Thr) 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. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMC3 NM_005445.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.62

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 Pathogenic. Variant got 13 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), SMC3. . Gene score misZ 6.3999 (greater than the threshold 3.09). Trascript score misZ 7.6232 (greater than threshold 3.09). GenCC has associacion of gene with Cornelia de Lange syndrome, Cornelia de Lange syndrome 3.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.893
• PP5: Variant 10-110581962-T-C is Pathogenic according to our data. Variant chr10-110581962-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 209193.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SMC3	NM_005445.4	c.587T>C	p.Ile196Thr	missense_variant	9/29	ENST00000361804.5	NP_005436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
SMC3	ENST00000361804.5	c.587T>C	p.Ile196Thr	missense_variant	9/29	1	NM_005445.4	ENSP00000354720	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Sep 18, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 30158690, 26633545) -

Cornelia de Lange syndrome 3 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Aug 30, 2014

Likely pathogenicity based on finding it once in our laboratory de novo in an 18-year-old male with autism, intellectual disability, hearing loss, dysmorphisms, hyperextensibility, short stature, mild scoliosis, platyspondyly, arachnodactyly, narrow hands. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.39	T
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.53	D
MetaRNN	Pathogenic	0.89	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.8	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-4.6	D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.82
MutPred		0.51		Loss of stability (P = 0.0282);
MVP		0.94
MPC		3.5
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.87
gMVP		0.96

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: rs797045070; hg19: chr10-112341720;