1-207506000-G-C

Variant names:

• chr1-207506000-G-C
• rs1387422169
• NM_000651.6:c.218G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000651.6(CR1):​c.218G>C​(p.Cys73Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. C73F) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: CR1 NM_000651.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.88
• Publications: 0 publications found

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

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.968

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000651.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CR1	NM_000651.6	MANE Select	c.218G>C	p.Cys73Ser	missense	Exon 2 of 47	NP_000642.3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CR1	ENST00000367049.9	TSL:5 MANE Select	c.218G>C	p.Cys73Ser	missense	Exon 2 of 47	ENSP00000356016.4	E9PDY4
	CR1	ENST00000400960.7	TSL:1	c.218G>C	p.Cys73Ser	missense	Exon 2 of 39	ENSP00000383744.2	P17927
	CR1	ENST00000367050.8	TSL:1	n.339G>C		non_coding_transcript_exon	Exon 2 of 13

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 6.84e-7 AC: 1 AN: 1461672 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727128

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53402

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111850

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Uncertain	24
DANN	Uncertain	0.99
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.47
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.80	T
M_CAP	Uncertain	0.097	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	0.97	D
PhyloP100		3.9
PrimateAI	Uncertain	0.50	T
PROVEAN	Pathogenic	-4.6	D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.59
MutPred		0.85		Gain of disorder (P = 0.0049)
MVP		0.97
MPC		0.44
ClinPred		0.99	D
GERP RS		4.1
gMVP		0.95
Mutation Taster		=35/65	disease causing

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

Other links and lift over

dbSNP: rs1387422169; hg19: chr1-207679345;