1-207523952-C-A

Variant names:

• chr1-207523952-C-A
• rs199777103
• NM_000651.6:c.829C>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000651.6(CR1):​c.829C>A​(p.Arg277Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,459,506 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/19 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R277C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CR1 NM_000651.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -0.161

Genes affected

CR1 (HGNC:2334): (complement C3b/C4b receptor 1 (Knops blood group)) This gene is a member of the receptors of complement activation (RCA) family and is located in the 'cluster RCA' region of chromosome 1. The genome is polymorphic at this locus with allele-specific splice variants encoding different isoforms, based on the presence/absence of long homologous repeats (LHRs). The gene encodes a monomeric single-pass type I membrane glycoprotein found on erythrocytes, leukocytes, glomerular podocytes, and splenic follicular dendritic cells. The Knops blood group system is a system of antigens located on this protein. The protein mediates cellular binding to particles and immune complexes that have activated complement. Decreases in expression of this protein and/or mutations in this gene have been associated with gallbladder carcinomas, mesangiocapillary glomerulonephritis, systemic lupus erythematosus, sarcoidosis and Alzheimer's disease. Mutations in this gene have also been associated with a reduction in Plasmodium falciparum rosetting, conferring protection against severe malaria. [provided by RefSeq, May 2020]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.10980749).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CR1	NM_000651.6	c.829C>A	p.Arg277Ser	missense_variant	Exon 5 of 47	ENST00000367049.9	NP_000642.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CR1	ENST00000367049.9	c.829C>A	p.Arg277Ser	missense_variant	Exon 5 of 47	5	NM_000651.6	ENSP00000356016.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000407 AC: 1 AN: 245680 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 133908

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 SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1459506 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 726038

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: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000832 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.28
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.41
CADD	Benign	2.4
DANN	Benign	0.30
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.00056	N
LIST_S2	Benign	0.18	.;.;T;T
M_CAP	Benign	0.0088	T
MetaRNN	Benign	0.11	T;T;T;T
MetaSVM	Benign	-1.0	T
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-1.3	N;N;N;N
REVEL	Benign	0.14
Sift	Benign	0.74	T;T;T;T
Sift4G	Benign	0.88	T;T;T;T
Polyphen		0.0	.;.;.;B
Vest4		0.10
MutPred		0.48		Loss of MoRF binding (P = 0.0124);Loss of MoRF binding (P = 0.0124);Loss of MoRF binding (P = 0.0124);Loss of MoRF binding (P = 0.0124);
MVP		0.33
MPC		2.7
ClinPred		0.032	T
GERP RS		-1.4
gMVP		0.46

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: rs199777103; hg19: chr1-207697297;