1-56929499-G-A

Variant names:

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_000066.4(C8B):c.1681C>T(p.Arg561Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000663 in 1,613,740 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/19 in silico tools predict a benign 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. R561H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000066 ( 0 hom. )

Consequence

C8B
NM_000066.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.61

Variant links:

Genes affected

C8B (HGNC:1353): (complement C8 beta chain) This gene encodes one of the three subunits of the complement component 8 (C8) protein. C8 is composed of equimolar amounts of alpha, beta and gamma subunits, which are encoded by three separate genes. C8 is one component of the membrane attack complex, which mediates cell lysis, and it initiates membrane penetration of the complex. This protein mediates the interaction of C8 with the C5b-7 membrane attack complex precursor. In humans deficiency of this protein is associated with increased risk of meningococcal infections. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jun 2013]

C8B links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.026305586).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
C8B	NM_000066.4 link	c.1681C>T	p.Arg561Cys	missense_variant	Exon 12 of 12	ENST00000371237.9	NP_000057.3	P07358
C8B	NM_001278543.2 link	c.1525C>T	p.Arg509Cys	missense_variant	Exon 13 of 13		NP_001265472.2	B7Z555
C8B	NM_001278544.2 link	c.1495C>T	p.Arg499Cys	missense_variant	Exon 13 of 13		NP_001265473.2	B7Z550

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
C8B	ENST00000371237.9 link	c.1681C>T	p.Arg561Cys	missense_variant	Exon 12 of 12	1	NM_000066.4	ENSP00000360281.4		P07358

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

Gnomad SAS

AF:

0.000829

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000104

AC:

AN:

250300

Hom.:

AF XY:

0.000126

AC XY:

AN XY:

135338

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000272

Gnomad SAS exome

AF:

0.000621

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000888

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000664

AC:

AN:

1461464

Hom.:

Cov.:

AF XY:

0.0000701

AC XY:

AN XY:

727044

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.0000765

Gnomad4 EAS exome

AF:

0.000126

Gnomad4 SAS exome

AF:

0.000673

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000180

Gnomad4 OTH exome

AF:

0.000149

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152276

Hom.:

Cov.:

AF XY:

0.0000940

AC XY:

AN XY:

74456

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000386

Gnomad4 SAS

AF:

0.000830

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000416

ExAC

AF:

0.000123

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Oct 18, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine with cysteine at codon 561 of the C8B protein (p.Arg561Cys). The arginine residue is weakly conserved and there is a large physicochemical difference between arginine and cysteine. This variant is present in population databases (rs567887687, ExAC 0.08%). This variant has not been reported in the literature in individuals affected with C8B-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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

0.20

BayesDel_addAF

Benign

-0.47

BayesDel_noAF

Benign

-0.55

CADD

Uncertain

DANN

Uncertain

0.99

DEOGEN2

Benign

0.12

.;T;.

Eigen

Benign

-0.15

Eigen_PC

Benign

-0.17

FATHMM_MKL

Benign

0.71

LIST_S2

Uncertain

0.91

.;D;D

M_CAP

Benign

0.0083

MetaRNN

Benign

0.026

T;T;T

MetaSVM

Benign

-1.0

PrimateAI

Benign

0.19

PROVEAN

Benign

-2.1

N;N;N

REVEL

Benign

0.041

Sift

Benign

0.068

T;T;T

Sift4G

Uncertain

0.026

D;D;D

Polyphen

0.82

.;P;P

Vest4

0.15

MutPred

0.40

Loss of MoRF binding (P = 0.0381);.;.;

MVP

0.44

MPC

0.19

ClinPred

0.083

GERP RS

2.7

gMVP

0.62

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over