rs781325598

Variant names:

• chr2-196875774-CTGTA-C
• rs781325598
• NM_024989.4:c.1394_1397delTACA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_024989.4(PGAP1):​c.1394_1397delTACA​(p.Ile465SerfsTer4) variant causes a frameshift change. The variant allele was found at a frequency of 0.00000389 in 1,542,214 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000022 (0 hom.)
• Consequence: PGAP1 NM_024989.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 5.46

Genes affected

PGAP1 (HGNC:25712): (post-GPI attachment to proteins inositol deacylase 1) The protein encoded by this gene functions early in the glycosylphosphatidylinositol (GPI) biosynthetic pathway, catalyzing the inositol deacylation of GPI. The encoded protein is required for the production of GPI that can attach to proteins, and this may be an important factor in the transport of GPI-anchored proteins from the endoplasmic reticulum to the Golgi. Defects in this gene are a cause an autosomal recessive form of cognitive impairment. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-196875774-CTGTA-C is Pathogenic according to our data. Variant chr2-196875774-CTGTA-C is described in ClinVar as [Pathogenic]. Clinvar id is 474988.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PGAP1	NM_024989.4	c.1394_1397delTACA	p.Ile465SerfsTer4	frameshift_variant	Exon 14 of 27	ENST00000354764.9	NP_079265.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PGAP1	ENST00000354764.9	c.1394_1397delTACA	p.Ile465SerfsTer4	frameshift_variant	Exon 14 of 27	1	NM_024989.4	ENSP00000346809.3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152138 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000196

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000816 AC: 2 AN: 245128 Hom.: 0 AF XY: 0.00000755 AC XY: 1 AN XY: 132490

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000602

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000216 AC: 3 AN: 1389958 Hom.: 0 AF XY: 0.00000288 AC XY: 2 AN XY: 694376

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000232

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000190

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152256 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74448

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000196

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000264

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Intellectual disability, autosomal recessive 42 Pathogenic:2

Dec 01, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Ile465Serfs*4) in the PGAP1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PGAP1 are known to be pathogenic (PMID: 17711852, 26050939, 27848944). This variant is present in population databases (rs781325598, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with PGAP1-related conditions. ClinVar contains an entry for this variant (Variation ID: 474988). For these reasons, this variant has been classified as Pathogenic. -

Feb 20, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: PGAP1 c.1394_1397delTACA (p.Ile465SerfsX4) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 8.2e-06 in 245128 control chromosomes. To our knowledge, no occurrence of c.1394_1397delTACA in individuals affected with Intellectual Disability, Autosomal Recessive 42 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 474988). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Oct 18, 2023

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

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: rs781325598; hg19: chr2-197740498;