rs775719725

Variant names:

• chr1-56929468-G-A
• rs775719725
• NM_000066.4:c.1712C>T

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000066.4(C8B):​c.1712C>T​(p.Pro571Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: C8B NM_000066.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.60
• Publications: 0 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 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.845

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000066.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C8B	NM_000066.4	MANE Select	c.1712C>T	p.Pro571Leu	missense	Exon 12 of 12	NP_000057.3	P07358
	C8B	NM_001278543.2		c.1556C>T	p.Pro519Leu	missense	Exon 13 of 13	NP_001265472.2
	C8B	NM_001278544.2		c.1526C>T	p.Pro509Leu	missense	Exon 13 of 13	NP_001265473.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	C8B	ENST00000371237.9	TSL:1 MANE Select	c.1712C>T	p.Pro571Leu	missense	Exon 12 of 12	ENSP00000360281.4	P07358
	C8B	ENST00000696164.1		c.1712C>T	p.Pro571Leu	missense	Exon 13 of 13	ENSP00000512454.1	A0A8Q3WL56
	C8B	ENST00000875298.1		c.1712C>T	p.Pro571Leu	missense	Exon 13 of 13	ENSP00000545357.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251000 AF XY: 0.00000737

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460896 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 726764

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33432

American (AMR) AF: 0.00 AC: 0 AN: 44700

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

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86198

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5114

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111894

Other (OTH) AF: 0.00 AC: 0 AN: 60310

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Uncertain	0.097	D
BayesDel_noAF	Benign	-0.10
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.50	T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Benign	0.039	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Uncertain	-0.26	T
PhyloP100		7.6
PrimateAI	Benign	0.40	T
PROVEAN	Pathogenic	-9.0	D
REVEL	Uncertain	0.54
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.77
MutPred		0.55		Loss of glycosylation at P571 (P = 0.0189)
MVP		0.81
MPC		0.28
ClinPred		1.0	D
GERP RS		3.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
gMVP		0.86
Mutation Taster		=52/48	polymorphism

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

Other links and lift over

dbSNP: rs775719725; hg19: chr1-57395141;