chr1-56867686-C-T

Position:

chr1-56867686-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000562.3(C8A):c.155C>T(p.Pro52Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,613,656 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. P52P) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

C8A
NM_000562.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.38

Variant links:

Genes affected

C8A (HGNC:1352): (complement C8 alpha chain) C8 is a component of the complement system and contains three polypeptides, alpha, beta and gamma. This gene encodes the alpha subunit of C8. C8 participates in the formation of the membrane attack complex (MAC). The MAC assembles on bacterial membranes to form a pore, permitting disruption of bacterial membrane organization. Mutations in this gene cause complement C8 alpha-gamma deficiency. [provided by RefSeq, Nov 2008]

C8A links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
C8A	NM_000562.3 linkuse as main transcript	c.155C>T	p.Pro52Leu	missense_variant	2/11	ENST00000361249.4
C8A	XM_017002234.2 linkuse as main transcript	c.155C>T	p.Pro52Leu	missense_variant	2/8
C8A	XM_011542079.3 linkuse as main transcript	c.155C>T	p.Pro52Leu	missense_variant	2/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C8A	ENST00000361249.4 linkuse as main transcript	c.155C>T	p.Pro52Leu	missense_variant	2/11	1	NM_000562.3	P4

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

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:

0.0000199

AC:

AN:

251024

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135656

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000164

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:

0.00000890

AC:

AN:

1461416

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727034

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000810

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152240

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74424

show subpopulations

Gnomad4 AFR

AF:

0.0000722

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000329

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.0000330

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 15, 2023

The c.155C>T (p.P52L) alteration is located in exon 2 (coding exon 2) of the C8A gene. This alteration results from a C to T substitution at nucleotide position 155, causing the proline (P) at amino acid position 52 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 22, 2022

This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 52 of the C8A protein (p.Pro52Leu). This variant is present in population databases (rs200247116, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with C8A-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: "Probably Damaging"; Align-GVGD: "Class C15"). 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

0.11

BayesDel_addAF

Benign

-0.23

BayesDel_noAF

Benign

-0.34

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.19

Eigen

Uncertain

0.40

Eigen_PC

Uncertain

0.34

FATHMM_MKL

Benign

0.57

LIST_S2

Benign

0.78

M_CAP

Benign

0.021

MetaRNN

Uncertain

0.56

MetaSVM

Benign

-1.0

MutationAssessor

Pathogenic

3.4

MutationTaster

Benign

1.0

PrimateAI

Benign

0.36

PROVEAN

Pathogenic

-7.1

REVEL

Benign

0.23

Sift

Uncertain

0.0030

Sift4G

Uncertain

0.0030

Polyphen

1.0

Vest4

0.49

MVP

0.59

MPC

0.22

ClinPred

0.83

GERP RS

4.2

Varity_R

0.72

gMVP

0.46

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