rs587777028

Positions:

• chr20-45424494-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_015937.6(PIGT):​c.1401-2A>G variant causes a splice acceptor, intron change involving the alteration of a 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 risk factor (no stars).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIGT NM_015937.6 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: risk factor no assertion criteria provided O:1
• Conservation: PhyloP100: 8.57

Genes affected

PIGT (HGNC:14938): (phosphatidylinositol glycan anchor biosynthesis class T) This gene encodes a protein that is involved in glycosylphosphatidylinositol (GPI)-anchor biosynthesis. The GPI-anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. This protein is an essential component of the multisubunit enzyme, GPI transamidase. GPI transamidase mediates GPI anchoring in the endoplasmic reticulum, by catalyzing the transfer of fully assembled GPI units to proteins. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, May 2012]

PIGT (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.047783535 fraction of the gene. Cryptic splice site detected, with MaxEntScore 11, offset of 15, new splice context is: tgtggcccatctgtcctcAGcgc. Cryptic site results in inframe 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PIGT	NM_015937.6	c.1401-2A>G		splice_acceptor_variant, intron_variant		ENST00000279036.12	NP_057021.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIGT	ENST00000279036.12	c.1401-2A>G		splice_acceptor_variant, intron_variant		1	NM_015937.6	ENSP00000279036.6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: risk factor

Submissions summary: Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Paroxysmal nocturnal hemoglobinuria 2 Other:1

risk factor, no assertion criteria provided

literature only

OMIM

Aug 15, 2013

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.38
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
GERP RS		5.9

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.75		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.40		Position offset: -42
DS_AL_spliceai		0.75		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs587777028; hg19: chr20-44053134;