chr1-207322380-A-C

Position:

• chr1-207322380-A-C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_Strong PM2 PP3_Strong PP5_Moderate

The NM_000574.5(CD55):​c.101-2A>C variant causes a splice acceptor change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CD55 NM_000574.5 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.60

Genes affected

CD55 (HGNC:2665): (CD55 molecule (Cromer blood group)) This gene encodes a glycoprotein involved in the regulation of the complement cascade. Binding of the encoded protein to complement proteins accelerates their decay, thereby disrupting the cascade and preventing damage to host cells. Antigens present on this protein constitute the Cromer blood group system (CROM). Alternative splicing results in multiple transcript variants. The predominant transcript variant encodes a membrane-bound protein, but alternatively spliced transcripts may produce soluble proteins. [provided by RefSeq, Jul 2014]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.16143106 fraction of the gene. Cryptic splice site detected, with MaxEntScore 5.2, offset of -20, new splice context is: ttgatagtcatttccttcAGttc. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 1-207322380-A-C is Pathogenic according to our data. Variant chr1-207322380-A-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2631765.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CD55	NM_000574.5	c.101-2A>C		splice_acceptor_variant		ENST00000367064.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CD55	ENST00000367064.9	c.101-2A>C		splice_acceptor_variant		1	NM_000574.5	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

CD55-related disorder Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Aug 09, 2023

The CD55 c.101-2A>C variant is predicted to disrupt the AG splice acceptor site and interfere with normal splicing. To our knowledge, this variant has not been reported in the literature or in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Variants that disrupt the consensus splice acceptor site in CD55 are expected to be pathogenic. This variant is interpreted as likely pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Benign	-0.10
CADD	Pathogenic	33
DANN	Uncertain	0.98
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.95	D
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
GERP RS		5.3
RBP_binding_hub_radar		0.67
RBP_regulation_power_radar		2.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.70		Position offset: 23
DS_AL_spliceai		1.0		Position offset: 2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr1-207495725;