10-110567823-A-G

Variant names:

• chr10-110567823-A-G
• rs1860796091
• NM_005445.4:c.7A>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_005445.4(SMC3):​c.7A>G​(p.Ile3Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,461,192 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I3R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: SMC3 NM_005445.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.93
• Publications: 0 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: Uncertain_significance. The variant received 4 ACMG points.

• 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: MetaRNN computational evidence supports a deleterious effect, 0.784

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SMC3	NM_005445.4	c.7A>G	p.Ile3Val	missense_variant	Exon 1 of 29	ENST00000361804.5	NP_005436.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SMC3	ENST00000361804.5	c.7A>G	p.Ile3Val	missense_variant	Exon 1 of 29	1	NM_005445.4	ENSP00000354720.5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461192 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 726938

African (AFR) AF: 0.00 AC: 0 AN: 33468

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39692

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53064

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111758

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cornelia de Lange syndrome 3 Uncertain:1

Aug 12, 2019

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was classified as: Uncertain significance. The available evidence on this variant's pathogenicity is insufficient or conflicting. The following ACMG criteria were applied in classifying this variant: PM2,PP2,PP3. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.34
BayesDel_addAF	Uncertain	0.097	D
BayesDel_noAF	Benign	-0.10
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.19	T
Eigen	Uncertain	0.62
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	D
M_CAP	Pathogenic	0.52	D
MetaRNN	Pathogenic	0.78	D
MetaSVM	Uncertain	0.023	D
MutationAssessor	Uncertain	2.7	M
PhyloP100		4.9
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.66	N
REVEL	Uncertain	0.48
Sift	Uncertain	0.0080	D
Sift4G	Benign	0.24	T
Polyphen		1.0	D
Vest4		0.58
MutPred		0.76		Loss of catalytic residue at I3 (P = 0.0787);
MVP		0.74
MPC		2.8
ClinPred		0.94	D
GERP RS		5.1
PromoterAI		0.11	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.45
gMVP		0.48
Mutation Taster		=88/12	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.31		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.31		Position offset: -5

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

Other links and lift over

dbSNP: rs1860796091; hg19: chr10-112327581;