chr19-6677923-C-A

Position:

• chr19-6677923-C-A

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM2 PP2 BP4_Strong

The NM_000064.4(C3):​c.4951G>T​(p.Ala1651Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,356 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: C3 NM_000064.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -1.25

Genes affected

C3 (HGNC:1318): (complement C3) Complement component C3 plays a central role in the activation of complement system. Its activation is required for both classical and alternative complement activation pathways. The encoded preproprotein is proteolytically processed to generate alpha and beta subunits that form the mature protein, which is then further processed to generate numerous peptide products. The C3a peptide, also known as the C3a anaphylatoxin, modulates inflammation and possesses antimicrobial activity. Mutations in this gene are associated with atypical hemolytic uremic syndrome and age-related macular degeneration in human patients. [provided by RefSeq, Nov 2015]

ACMG classification

Verdict is Likely_benign. Variant got -1 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), C3. . Gene score misZ 2.7489 (greater than the threshold 3.09). Trascript score misZ 4.431 (greater than threshold 3.09). GenCC has associacion of gene with complement component 3 deficiency, C3 glomerulonephritis, atypical hemolytic-uremic syndrome with C3 anomaly.
• BP4: Computational evidence support a benign effect (MetaRNN=0.046157718).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
C3	NM_000064.4	c.4951G>T	p.Ala1651Ser	missense_variant	41/41	ENST00000245907.11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C3	ENST00000245907.11	c.4951G>T	p.Ala1651Ser	missense_variant	41/41	1	NM_000064.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000660 AC: 1 AN: 151528 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

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461828 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727208

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000660 AC: 1 AN: 151528 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 73980

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: 0.00000378

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

Labcorp Genetics (formerly Invitae), Labcorp

Oct 13, 2023

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 1651 of the C3 protein (p.Ala1651Ser). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with C3-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt C3 protein function. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
BayesDel_addAF	Benign	-0.23	T
BayesDel_noAF	Benign	-0.56
CADD	Benign	0.033
DANN	Benign	0.52
DEOGEN2	Benign	0.035	T;T
Eigen	Benign	-2.0
Eigen_PC	Benign	-2.0
FATHMM_MKL	Benign	0.079	N
LIST_S2	Benign	0.13	T;T
M_CAP	Uncertain	0.12	D
MetaRNN	Benign	0.046	T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.11	N;.
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.35	T
PROVEAN	Benign	0.35	N;.
REVEL	Benign	0.049
Sift	Benign	0.52	T;.
Sift4G	Benign	0.49	T;D
Polyphen		0.0	B;.
Vest4		0.043
MutPred		0.34		Gain of disorder (P = 0.0071);.;
MVP		0.36
MPC		0.53
ClinPred		0.028	T
GERP RS		-5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.11
gMVP		0.48

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: rs756442896; hg19: chr19-6677934;