rs1135402918

Variant names:

• chr1-207324558-G-A
• rs1135402918
• NM_000574.5:c.287-1G>A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_000574.5(CD55):​c.287-1G>A variant causes a splice acceptor, intron change involving the alteration of a non-conserved nucleotide. 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 Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: CD55 NM_000574.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 2.94
• Publications: 0 publications found

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]

CD55 Gene-Disease associations (from GenCC):

• protein-losing enteropathy

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.16753927 fraction of the gene. Cryptic splice site detected, with MaxEntScore 6.4, offset of 47, new splice context is: attctgcatccctcaaacAGcct. 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
• PP5: Variant 1-207324558-G-A is Pathogenic according to our data. Variant chr1-207324558-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 431763.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000574.5. 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
	CD55	NM_000574.5	MANE Select	c.287-1G>A		splice_acceptor intron	N/A	NP_000565.1	P08174-1
	CD55	NM_001300902.2		c.287-1G>A		splice_acceptor intron	N/A	NP_001287831.1	B1AP13
	CD55	NM_001114752.3		c.287-1G>A		splice_acceptor intron	N/A	NP_001108224.1	P08174-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CD55	ENST00000367064.9	TSL:1 MANE Select	c.287-1G>A		splice_acceptor intron	N/A	ENSP00000356031.4	P08174-1
	CD55	ENST00000367063.6	TSL:1	c.287-1G>A		splice_acceptor intron	N/A	ENSP00000356030.2	B1AP13
	CD55	ENST00000314754.12	TSL:1	c.287-1G>A		splice_acceptor intron	N/A	ENSP00000316333.8	P08174-2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Complement hyperactivation-angiopathic thrombosis-protein-losing enteropathy syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.95	D
PhyloP100		2.9
GERP RS		6.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.87
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.47		Position offset: 48
DS_AL_spliceai		0.99		Position offset: 1

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

Other links and lift over

dbSNP: rs1135402918; hg19: chr1-207497903;