NM_005445.4:c.1964G>A

Variant names:

• chr10-110596398-G-A
• rs587784425
• NM_005445.4:c.1964G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP2 PP3 PP5_Moderate

The NM_005445.4(SMC3):​c.1964G>A​(p.Gly655Asp) variant causes a missense, splice region 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. 15/24 in silico tools predict a damaging outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: SMC3 NM_005445.4 missense, splice_region
• Scores: Splicing: ADA: 0.9982
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 9.50
• Publications: 4 publications found

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]

SMC3 Gene-Disease associations (from GenCC):

• Cornelia de Lange syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• Cornelia de Lange syndrome 3

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_005445.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the SMC3 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 44 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 6.3999 (above the threshold of 3.09). Trascript score misZ: 7.6232 (above the threshold of 3.09). GenCC associations: The gene is linked to Cornelia de Lange syndrome 3, Cornelia de Lange syndrome.
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
• PP5: Variant 10-110596398-G-A is Pathogenic according to our data. Variant chr10-110596398-G-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 159970.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMC3	NM_005445.4	c.1964G>A	p.Gly655Asp	missense_variant, splice_region_variant	Exon 19 of 29	ENST00000361804.5	NP_005436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMC3	ENST00000361804.5	c.1964G>A	p.Gly655Asp	missense_variant, splice_region_variant	Exon 19 of 29	1	NM_005445.4	ENSP00000354720.5
SMC3	ENST00000684988.1	n.2609G>A		splice_region_variant, non_coding_transcript_exon_variant	Exon 17 of 25
SMC3	ENST00000692792.1	n.2083G>A		splice_region_variant, non_coding_transcript_exon_variant	Exon 19 of 19

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Cornelia de Lange syndrome 3 Pathogenic:2

Jan 13, 2014

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 01, 2015

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.68	D
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.93	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		9.5
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.61		Gain of solvent accessibility (P = 0.1583);
MVP		0.99
MPC		2.6
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.97
gMVP		0.98
Mutation Taster		=33/67	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.83
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs587784425; hg19: chr10-112356156;