chr1-56956799-G-C

Variant names:

• chr1-56956799-G-C
• rs150022116
• NM_000066.4:c.361C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The ENST00000371237.9(C8B):​c.361C>G​(p.Arg121Gly) 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 1,613,792 control chromosomes in the GnomAD database, with no homozygous occurrence. 12/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R121R) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: C8B ENST00000371237.9 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.36
• Publications: 6 publications found

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 Gene-Disease associations (from GenCC):

• type II complement component 8 deficiency

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000371237.9. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C8B	NM_000066.4	MANE Select	c.361C>G	p.Arg121Gly	missense	Exon 3 of 12	NP_000057.3
	C8B	NM_001278543.2		c.205C>G	p.Arg69Gly	missense	Exon 4 of 13	NP_001265472.2
	C8B	NM_001278544.2		c.175C>G	p.Arg59Gly	missense	Exon 4 of 13	NP_001265473.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C8B	ENST00000371237.9	TSL:1 MANE Select	c.361C>G	p.Arg121Gly	missense	Exon 3 of 12	ENSP00000360281.4
	C8B	ENST00000696164.1		c.361C>G	p.Arg121Gly	missense	Exon 4 of 13	ENSP00000512454.1
	C8B	ENST00000695842.1		c.361C>G	p.Arg121Gly	missense	Exon 3 of 11	ENSP00000512214.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152002 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: 1461790 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 727210

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000360 AC: 4 AN: 1111942

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152002 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74226

African (AFR) AF: 0.00 AC: 0 AN: 41396

American (AMR) AF: 0.00 AC: 0 AN: 15262

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5148

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10576

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68022

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 1

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.15	T
BayesDel_noAF	Benign	-0.45
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Benign	0.028	T
Eigen	Benign	-0.12
Eigen_PC	Benign	-0.011
FATHMM_MKL	Benign	0.33	N
LIST_S2	Uncertain	0.88	D
M_CAP	Benign	0.0072	T
MetaRNN	Uncertain	0.51	D
MetaSVM	Benign	-1.1	T
PhyloP100		1.4
PrimateAI	Benign	0.40	T
PROVEAN	Uncertain	-2.6	D
REVEL	Benign	0.18
Sift	Benign	0.15	T
Sift4G	Benign	0.40	T
Polyphen		0.98	D
Vest4		0.54
MutPred		0.67		Loss of MoRF binding (P = 0.082)
MVP		0.55
MPC		0.13
ClinPred		0.83	D
GERP RS		5.4
gMVP		0.63
Mutation Taster		=82/18	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs150022116; hg19: chr1-57422472;