chr1-56929457-T-C

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.1723A>G(p.Asn575Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000143 in 1,612,980 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 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. N575N) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

C8B
NM_000066.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 1.04

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=0.029913992).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
C8B	NM_000066.4 link	c.1723A>G	p.Asn575Asp	missense_variant	Exon 12 of 12	ENST00000371237.9	NP_000057.3	P07358
C8B	NM_001278543.2 link	c.1567A>G	p.Asn523Asp	missense_variant	Exon 13 of 13		NP_001265472.2	B7Z555
C8B	NM_001278544.2 link	c.1537A>G	p.Asn513Asp	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.1723A>G	p.Asn575Asp	missense_variant	Exon 12 of 12	1	NM_000066.4	ENSP00000360281.4		P07358

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152172

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000771

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000438

AC:

AN:

251124

Hom.:

AF XY:

0.0000442

AC XY:

AN XY:

135732

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000544

Gnomad SAS 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:

0.0000130

AC:

AN:

1460690

Hom.:

Cov.:

AF XY:

0.0000138

AC XY:

AN XY:

726652

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000428

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152290

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74454

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000773

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000619

Hom.:

Bravo

AF:

0.0000340

ExAC

AF:

0.0000577

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Aug 27, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine with aspartic acid at codon 575 of the C8B protein (p.Asn575Asp). The asparagine residue is moderately conserved and there is a small physicochemical difference between asparagine and aspartic acid. This variant is present in population databases (rs190080984, ExAC 0.07%). 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 (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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

0.10

BayesDel_addAF

Benign

-0.57

BayesDel_noAF

Benign

-0.72

CADD

Benign

DANN

Benign

0.97

DEOGEN2

Benign

0.055

.;T;.

Eigen

Benign

-0.63

Eigen_PC

Benign

-0.65

FATHMM_MKL

Benign

0.68

LIST_S2

Benign

0.70

.;T;T

M_CAP

Benign

0.0020

MetaRNN

Benign

0.030

T;T;T

MetaSVM

Benign

-0.98

PrimateAI

Benign

0.34

PROVEAN

Uncertain

-2.6

D;D;D

REVEL

Benign

0.070

Sift

Benign

0.16

T;T;T

Sift4G

Benign

0.25

T;T;T

Polyphen

0.0010

.;B;B

Vest4

0.18

MVP

0.40

MPC

0.042

ClinPred

0.042

GERP RS

-0.12

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

gMVP

0.58

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