1-22637736-C-A

Position:

• chr1-22637736-C-A

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 2P and 7B. PM2 BP4_Strong BP6_Moderate BP7

The NM_015991.4(C1QA):​c.120C>A​(p.Gly40=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,456,282 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: C1QA NM_015991.4 synonymous
• Clinical Significance: Likely benign criteria provided, single submitter B:1
• Conservation: PhyloP100: -1.05

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]

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.61).
• BP6: Variant 1-22637736-C-A is Benign according to our data. Variant chr1-22637736-C-A is described in ClinVar as [Likely_benign]. Clinvar id is 1991738.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP7: Synonymous conserved (PhyloP=-1.05 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
C1QA	NM_015991.4	c.120C>A	p.Gly40=	synonymous_variant	2/3	ENST00000374642.8	NP_057075.1
C1QA	NM_001347465.2	c.120C>A	p.Gly40=	synonymous_variant	2/3		NP_001334394.1
C1QA	NM_001347466.2	c.120C>A	p.Gly40=	synonymous_variant	2/3		NP_001334395.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
C1QA	ENST00000374642.8	c.120C>A	p.Gly40=	synonymous_variant	2/3	1	NM_015991.4	ENSP00000363773	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1456282 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 723966

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000229

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

ClinVar

Significance: Likely benign

Submissions summary: Benign:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 10, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.61
CADD	Benign	5.6
DANN	Benign	0.49

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

Other links and lift over

dbSNP: rs775331515; hg19: chr1-22964229;