1-22637627-C-G

Position:

chr1-22637627-C-G

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2BP4_ModerateBS1_Supporting

The NM_015991.4(C1QA):c.11C>G(p.Pro4Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000522 in 1,613,938 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00023 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00055 ( 0 hom. )

Consequence

C1QA
NM_015991.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.246

Variant links:

Genes affected

C1QA (HGNC:1241): (complement C1q A chain) This gene encodes the A-chain polypeptide of serum complement subcomponent C1q, which associates with C1r and C1s to yield the first component of the serum complement system. C1q deficiency is associated with lupus erythematosus and glomerulonephritis. C1q is composed of 18 polypeptide chains which include 6 A-chains, 6 B-chains, and 6 C-chains. Each chain contains an N-terminal collagen-like region and a C-terminal C1q globular domain. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Nov 2016]

C1QA links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -1 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.1313951).

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.00023 (35/152164) while in subpopulation NFE AF= 0.000441 (30/68022). AF 95% confidence interval is 0.000317. There are 0 homozygotes in gnomad4. There are 10 alleles in male gnomad4 subpopulation. Median coverage is 33. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
C1QA	NM_015991.4 linkuse as main transcript	c.11C>G	p.Pro4Arg	missense_variant	2/3	ENST00000374642.8
C1QA	NM_001347465.2 linkuse as main transcript	c.11C>G	p.Pro4Arg	missense_variant	2/3
C1QA	NM_001347466.2 linkuse as main transcript	c.11C>G	p.Pro4Arg	missense_variant	2/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C1QA	ENST00000374642.8 linkuse as main transcript	c.11C>G	p.Pro4Arg	missense_variant	2/3	1	NM_015991.4	P1

Frequencies

GnomAD3 genomes

AF:

0.000230

AC:

AN:

152164

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000196

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:

0.000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000255

AC:

AN:

250862

Hom.:

AF XY:

0.000221

AC XY:

AN XY:

135652

show subpopulations

Gnomad AFR exome

AF:

0.0000617

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000529

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000553

AC:

808

AN:

1461774

Hom.:

Cov.:

AF XY:

0.000499

AC XY:

363

AN XY:

727176

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.0000895

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000678

Gnomad4 OTH exome

AF:

0.000745

GnomAD4 genome

AF:

0.000230

AC:

AN:

152164

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

74336

show subpopulations

Gnomad4 AFR

AF:

0.0000483

Gnomad4 AMR

AF:

0.000196

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000441

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000472

Hom.:

Bravo

AF:

0.000314

TwinsUK

AF:

0.000539

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000465

AC:

ExAC

AF:

0.000255

AC:

EpiCase

AF:

0.000818

EpiControl

AF:

0.000652

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 05, 2022

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 4 of the C1QA protein (p.Pro4Arg). This variant is present in population databases (rs149230484, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with C1QA-related conditions. ClinVar contains an entry for this variant (Variation ID: 1468526). 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: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

C1Q deficiency

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Aug 28, 2019

A heterozygous missense variant was identified, NM_015991.2(C1QA):c.11C>G in exon 2 of 3 of the C1QA gene. This substitution is predicted to create a major amino acid change from proline to arginine at position 4 of the protein, NP_057075.1(C1QA):p.(Pro4Arg). The proline at this position has low conservation (100 vertebrates, UCSC), and is located within the signal peptide motif. In silico software predictions of the pathogenicity of this variant are conflicting (Polyphen, SIFT, CADD, Mutation Taster). The variant is present in the gnomAD population database at a frequency of 0.02% (68 heterozygotes, 0 homozygotes). An alternative residue change to serine at the same location has been reported in the gnomAD database at a frequency of 0.0004% (1 heterozygote, 0 homozygotes). The variant has not previously been reported in clinical cases. Based on information available at the time of curation, this variant has been classified as a VARIANT of UNCERTAIN SIGNIFICANCE (VUS). -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.078

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.19

CADD

Benign

DANN

Uncertain

0.99

DEOGEN2

Benign

0.11

T;T;T

Eigen

Benign

-0.36

Eigen_PC

Benign

-0.44

FATHMM_MKL

Benign

0.16

LIST_S2

Benign

0.66

.;T;T

M_CAP

Uncertain

0.16

MetaRNN

Benign

0.13

T;T;T

MetaSVM

Uncertain

-0.16

MutationAssessor

Uncertain

2.4

M;.;M

MutationTaster

Benign

1.0

N;N

PrimateAI

Benign

0.32

PROVEAN

Benign

-0.77

N;N;N

REVEL

Uncertain

0.32

Sift

Uncertain

0.0070

D;T;D

Sift4G

Uncertain

0.0060

D;D;D

Polyphen

0.43

B;.;B

Vest4

0.36

MVP

0.85

MPC

1.1

ClinPred

0.088

GERP RS

4.0

Varity_R

0.052

gMVP

0.80

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