1-22659523-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001378156.1(C1QB):​c.61G>A​(p.Asp21Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000353 in 1,613,884 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

C1QB
NM_001378156.1 missense

Scores

19

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.00

Publications

1 publications found
Variant links:
Genes affected
C1QB (HGNC:1242): (complement C1q B chain) This gene encodes the B-chain polypeptide of serum complement subcomponent C1q, which associates with C1r and C1s to yield the first component of the serum complement system. 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. C1q deficiency is associated with lupus erythematosus and glomerulonephritis. [provided by RefSeq, Dec 2016]
C1QB Gene-Disease associations (from GenCC):
  • C1Q deficiency
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16129252).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
C1QBNM_001378156.1 linkc.61G>A p.Asp21Asn missense_variant Exon 2 of 3 ENST00000509305.6 NP_001365085.1
C1QBNM_000491.5 linkc.67G>A p.Asp23Asn missense_variant Exon 2 of 3 NP_000482.3 P02746A0A024RAB9
C1QBNM_001371184.3 linkc.61G>A p.Asp21Asn missense_variant Exon 3 of 4 NP_001358113.2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
C1QBENST00000509305.6 linkc.61G>A p.Asp21Asn missense_variant Exon 2 of 3 1 NM_001378156.1 ENSP00000423689.1 D6R934

Frequencies

GnomAD3 genomes
AF:
0.0000132
AC:
2
AN:
152056
Hom.:
0
Cov.:
32
show subpopulations
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000796
AC:
20
AN:
251312
AF XY:
0.0000957
show subpopulations
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:
0.000158
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000376
AC:
55
AN:
1461828
Hom.:
0
Cov.:
32
AF XY:
0.0000371
AC XY:
27
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44712
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86250
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000450
AC:
50
AN:
1111984
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60392
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000132
AC:
2
AN:
152056
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74266
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41356
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4822
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.400
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000434
Hom.:
0
Bravo
AF:
0.0000189
ExAC
AF:
0.000132
AC:
16
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Jan 20, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.67G>A (p.D23N) alteration is located in exon 2 (coding exon 1) of the C1QB gene. This alteration results from a G to A substitution at nucleotide position 67, causing the aspartic acid (D) at amino acid position 23 to be replaced by an asparagine (N). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided Uncertain:1
Dec 05, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals with C1QB-related conditions. This sequence change replaces aspartic acid with asparagine at codon 23 of the C1QB protein (p.Asp23Asn). The aspartic acid residue is weakly conserved and there is a small physicochemical difference between aspartic acid and asparagine. This variant is present in population databases (rs555943495, ExAC 0.02%). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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 2 Uncertain:1
May 23, 2024
Fulgent Genetics, Fulgent Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.083
BayesDel_addAF
Benign
-0.27
T
BayesDel_noAF
Benign
-0.37
CADD
Benign
11
DANN
Benign
0.50
DEOGEN2
Benign
0.019
.;T;T;T
Eigen
Benign
-1.2
Eigen_PC
Benign
-1.2
FATHMM_MKL
Benign
0.12
N
LIST_S2
Benign
0.41
T;T;T;T
M_CAP
Benign
0.044
D
MetaRNN
Benign
0.16
T;T;T;T
MetaSVM
Benign
-0.62
T
MutationAssessor
Benign
1.3
.;.;.;L
PhyloP100
2.0
PrimateAI
Benign
0.27
T
PROVEAN
Benign
0.32
N;N;N;N
REVEL
Benign
0.16
Sift
Benign
0.46
T;T;T;T
Sift4G
Benign
0.49
T;T;T;T
Polyphen
0.22
.;.;.;B
Vest4
0.18, 0.15
MutPred
0.39
.;.;.;Gain of helix (P = 0.132);
MVP
0.76
MPC
0.47
ClinPred
0.039
T
GERP RS
1.2
Varity_R
0.036
gMVP
0.36
Mutation Taster
=97/3
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

Publications

Other links and lift over

dbSNP: rs555943495; hg19: chr1-22986016; COSMIC: COSV106454128; API