Genetic Variant C8B:p.Arg121Arg (chr1-56956799-G-T) – ACMG Classification: Likely_benign (-3 pts)

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_ModerateBP6_ModerateBP7

The NM_000066.4(C8B):c.361C>A(p.Arg121Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000105 in 1,613,792 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 Likely benign (★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00011 ( 0 hom. )

Consequence

C8B
NM_000066.4 synonymous

Scores

Clinical Significance

Likely benign criteria provided, single submitter B:1

Conservation

PhyloP100: 1.36

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:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (BayesDel_noAF=-0.35).

BP6

Variant 1-56956799-G-T is Benign according to our data. Variant chr1-56956799-G-T is described in ClinVar as [Likely_benign]. Clinvar id is 1523047.Status of the report is criteria_provided_single_submitter, 1 stars.

BP7

Synonymous conserved (PhyloP=1.36 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
C8B	NM_000066.4 link	c.361C>A	p.Arg121Arg	synonymous_variant	Exon 3 of 12	ENST00000371237.9	NP_000057.3	P07358
C8B	NM_001278543.2 link	c.205C>A	p.Arg69Arg	synonymous_variant	Exon 4 of 13		NP_001265472.2	B7Z555
C8B	NM_001278544.2 link	c.175C>A	p.Arg59Arg	synonymous_variant	Exon 4 of 13		NP_001265473.2	B7Z550
C8B	XM_047429957.1 link	c.361C>A	p.Arg121Arg	synonymous_variant	Exon 3 of 7		XP_047285913.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
C8B	ENST00000371237.9 link	c.361C>A	p.Arg121Arg	synonymous_variant	Exon 3 of 12	1	NM_000066.4	ENSP00000360281.4		P07358

Frequencies

GnomAD3 genomes

AF:

0.0000592

AC:

AN:

152002

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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:

0.000118

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000915

AC:

AN:

251312

Hom.:

AF XY:

0.000103

AC XY:

AN XY:

135816

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000131

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000150

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000110

AC:

161

AN:

1461790

Hom.:

Cov.:

AF XY:

0.000111

AC XY:

AN XY:

727210

show subpopulations

Gnomad4 AFR exome

AF:

0.0000896

Gnomad4 AMR exome

AF:

0.0000447

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.000220

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000118

Gnomad4 OTH exome

AF:

0.0000994

GnomAD4 genome

AF:

0.0000592

AC:

AN:

152002

Hom.:

Cov.:

AF XY:

0.0000539

AC XY:

AN XY:

74226

show subpopulations

Gnomad4 AFR

AF:

0.0000242

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:

0.000118

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000223

Hom.:

Bravo

AF:

0.0000529

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Benign:1

Dec 17, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_noAF

Benign

-0.35

CADD

Benign

DANN

Benign

0.79

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.18

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