1-56867634-G-A

Position:

chr1-56867634-G-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBP6

The NM_000562.3(C8A):c.103G>A(p.Ala35Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000502 in 1,613,656 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000049 ( 0 hom. )

Consequence

C8A
NM_000562.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:1

Conservation

PhyloP100: -1.18

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 Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.035909444).

BP6

Variant 1-56867634-G-A is Benign according to our data. Variant chr1-56867634-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2063157.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
C8A	NM_000562.3 linkuse as main transcript	c.103G>A	p.Ala35Thr	missense_variant	2/11	ENST00000361249.4
C8A	XM_017002234.2 linkuse as main transcript	c.103G>A	p.Ala35Thr	missense_variant	2/8
C8A	XM_011542079.3 linkuse as main transcript	c.103G>A	p.Ala35Thr	missense_variant	2/8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C8A	ENST00000361249.4 linkuse as main transcript	c.103G>A	p.Ala35Thr	missense_variant	2/11	1	NM_000562.3	P4

Frequencies

GnomAD3 genomes

AF:

0.0000657

AC:

AN:

152096

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000966

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:

0.0000944

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000637

AC:

AN:

251000

Hom.:

AF XY:

0.0000737

AC XY:

AN XY:

135634

show subpopulations

Gnomad AFR exome

AF:

0.000185

Gnomad AMR exome

AF:

0.0000580

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000273

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000486

AC:

AN:

1461442

Hom.:

Cov.:

AF XY:

0.0000550

AC XY:

AN XY:

727048

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000504

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000396

Gnomad4 OTH exome

AF:

0.0000663

GnomAD4 genome

AF:

0.0000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000403

AC XY:

AN XY:

74414

show subpopulations

Gnomad4 AFR

AF:

0.0000963

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.0000944

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000579

Hom.:

Bravo

AF:

0.0000718

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.0000577

AC:

EpiCase

AF:

0.0000546

EpiControl

AF:

0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 13, 2023

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 35 of the C8A protein (p.Ala35Thr). This variant is present in population databases (rs201034819, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with C8A-related conditions. ClinVar contains an entry for this variant (Variation ID: 2063157). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Not Available"; PolyPhen-2: "Benign"; Align-GVGD: "Not Available". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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. -

not specified

Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 05, 2024

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.064

BayesDel_addAF

Benign

-0.52

BayesDel_noAF

Benign

-0.68

CADD

Benign

0.045

DANN

Benign

0.48

DEOGEN2

Benign

0.010

Eigen

Benign

-1.8

Eigen_PC

Benign

-1.8

FATHMM_MKL

Benign

0.0072

LIST_S2

Benign

0.14

M_CAP

Benign

0.012

MetaRNN

Benign

0.036

MetaSVM

Benign

-1.0

MutationAssessor

Benign

-0.65

MutationTaster

Benign

1.0

PrimateAI

Benign

0.22

PROVEAN

Benign

-0.31

REVEL

Benign

0.12

Sift

Benign

0.63

Sift4G

Benign

0.66

Polyphen

0.0010

Vest4

0.17

MVP

0.50

MPC

0.031

ClinPred

0.0056

GERP RS

-8.4

Varity_R

0.053

gMVP

0.19

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