6-31927967-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000063.6(C2):c.59C>T(p.Ser20Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,950 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. S20S) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: C2 NM_000063.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.327

Genes affected

C2 (HGNC:1248): (complement C2) Component C2 is a serum glycoprotein that functions as part of the classical pathway of the complement system. Activated C1 cleaves C2 into C2a and C2b. The serine proteinase C2a then combines with complement factor 4b to create the C3 or C5 convertase. Deficiency of C2 has been reported to associated with certain autoimmune diseases and SNPs in this gene have been associated with altered susceptibility to age-related macular degeneration. This gene localizes within the class III region of the MHC on the short arm of chromosome 6. Alternative splicing results in multiple transcript variants encoding distinct isoforms. Additional transcript variants have been described in publications but their full-length sequence has not been determined.[provided by RefSeq, Mar 2009]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11295763).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
C2	NM_000063.6	c.59C>T	p.Ser20Leu	missense_variant	2/18	ENST00000299367.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C2	ENST00000299367.10	c.59C>T	p.Ser20Leu	missense_variant	2/18	1	NM_000063.6	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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

GnomAD3 exomes AF: 0.0000119 AC: 3 AN: 251478 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135920

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461786 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727212

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74336

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 20, 2022

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. This variant has not been reported in the literature in individuals affected with C2-related conditions. This variant is present in population databases (rs756248699, gnomAD 0.003%). This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 20 of the C2 protein (p.Ser20Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.083
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.34
Cadd	Benign	10
Dann	Uncertain	0.98
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.91
FATHMM_MKL	Benign	0.061	N
LIST_S2	Benign	0.64	T;T;T;T;T;T
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.11	T;T;T;T;T;T
MetaSVM	Benign	-0.91	T
MutationTaster	Benign	1.0	N;N;N;N;N;N
PrimateAI	Benign	0.34	T
PROVEAN	Benign	-1.6	N;N;N;N;N;N
REVEL	Benign	0.078
Sift	Benign	0.085	T;T;T;T;T;T
Sift4G	Uncertain	0.012	D;D;D;D;D;D
Polyphen		0.11, 0.049	.;B;.;B;.;.
Vest4		0.14, 0.12, 0.11, 0.12
MutPred		0.43		Loss of disorder (P = 0.0195);Loss of disorder (P = 0.0195);Loss of disorder (P = 0.0195);Loss of disorder (P = 0.0195);Loss of disorder (P = 0.0195);Loss of disorder (P = 0.0195);
MVP		0.73
MPC		0.27
ClinPred		0.082	T
GERP RS		3.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0
Varity_R		0.053
gMVP		0.24

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs756248699; hg19: chr6-31895744;