NM_005445.4:c.255A>T

Variant names:

• chr10-110577477-A-T
• rs146433240
• NM_005445.4:c.255A>T

Variant summary

Our verdict is Benign. The variant received -10 ACMG points: 0P and 10B. BP4_Strong BP6 BP7 BS2

The NM_005445.4(SMC3):​c.255A>T​(p.Ser85Ser) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000161 in 1,610,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. S85S) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000016 (0 hom.)
• Consequence: SMC3 NM_005445.4 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:2
• Conservation: PhyloP100: -1.12
• Publications: 6 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: PanelApp Australia, G2P, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Benign. The variant received -10 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP6: Variant 10-110577477-A-T is Benign according to our data. Variant chr10-110577477-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 287965.
• BP7: Synonymous conserved (PhyloP=-1.12 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 24 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_005445.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMC3	NM_005445.4	MANE Select	c.255A>T	p.Ser85Ser	synonymous	Exon 5 of 29	NP_005436.1	Q9UQE7

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	SMC3	ENST00000361804.5	TSL:1 MANE Select	c.255A>T	p.Ser85Ser	synonymous	Exon 5 of 29	ENSP00000354720.5	Q9UQE7
	SMC3	ENST00000918257.1		c.255A>T	p.Ser85Ser	synonymous	Exon 5 of 29	ENSP00000588316.1
	SMC3	ENST00000966376.1		c.273A>T	p.Ser91Ser	synonymous	Exon 5 of 29	ENSP00000636435.1

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152214 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000654

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251124 AF XY: 0.00

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000165 AC: 24 AN: 1458674 Hom.: 0 Cov.: 29 AF XY: 0.0000138 AC XY: 10 AN XY: 725942

African (AFR) AF: 0.00 AC: 0 AN: 33404

American (AMR) AF: 0.00 AC: 0 AN: 44718

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26096

East Asian (EAS) AF: 0.00 AC: 0 AN: 39560

South Asian (SAS) AF: 0.00 AC: 0 AN: 86158

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53314

Middle Eastern (MID) AF: 0.000174 AC: 1 AN: 5754

European-Non Finnish (NFE) AF: 0.0000162 AC: 18 AN: 1109412

Other (OTH) AF: 0.0000830 AC: 5 AN: 60258

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152214 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74372

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41476

American (AMR) AF: 0.0000654 AC: 1 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5196

South Asian (SAS) AF: 0.00 AC: 0 AN: 4836

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68014

Other (OTH) AF: 0.00 AC: 0 AN: 2092

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.00 Hom.: 1

Bravo AF: 0.0000491

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	-	1	Cornelia de Lange syndrome 3 (1)
-	-	1	Inborn genetic diseases (1)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	3.1
DANN	Benign	0.81
PhyloP100		-1.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

Other links and lift over

dbSNP: rs146433240; hg19: chr10-112337235;