17-5433128-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_001212.4(C1QBP):c.736C>T(p.Arg246Ter) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000205 in 1,461,838 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: C1QBP NM_001212.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.01

Genes affected

C1QBP (HGNC:1243): (complement C1q binding protein) The human complement subcomponent C1q associates with C1r and C1s in order to yield the first component of the serum complement system. The protein encoded by this gene is known to bind to the globular heads of C1q molecules and inhibit C1 activation. This protein has also been identified as the p32 subunit of pre-mRNA splicing factor SF2, as well as a hyaluronic acid-binding protein. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-5433128-G-A is Pathogenic according to our data. Variant chr17-5433128-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 1453425.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
C1QBP	NM_001212.4	c.736C>T	p.Arg246Ter	stop_gained	6/6	ENST00000225698.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
C1QBP	ENST00000225698.8	c.736C>T	p.Arg246Ter	stop_gained	6/6	1	NM_001212.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461838 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727222

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.00 AC: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jul 02, 2021

For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the C1QBP protein in which other variant(s) (p.Leu275Phe) have been determined to be pathogenic (PMID: 28942965, 33344382). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. This variant has not been reported in the literature in individuals affected with C1QBP-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change creates a premature translational stop signal (p.Arg246*) in the C1QBP gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 37 amino acid(s) of the C1QBP protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
Cadd	Pathogenic	38
Dann	Uncertain	1.0
Eigen	Uncertain	0.57
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.93	D
MutationTaster	Benign	1.0	D;D
Vest4		0.90
GERP RS		4.7
RBP_binding_hub_radar		0.92
RBP_regulation_power_radar		2.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs746170176; hg19: chr17-5336448;