NM_176787.5:c.1173-8A>G

Variant names:

• chr18-62114647-T-C
• rs76321419
• NM_176787.5:c.1173-8A>G

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM2 BP4_Strong BP6_Moderate

The NM_176787.5(PIGN):​c.1173-8A>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000168 in 1,370,706 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★).

• Frequency:
  • Genomes: 𝑓 0.000059 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000011 (0 hom.)
• Consequence: PIGN NM_176787.5 splice_region, intron
• Clinical Significance: Likely benign criteria provided, single submitter B:2
• Conservation: PhyloP100: 1.33
• Publications: 0 publications found

Genes affected

PIGN (HGNC:8967): (phosphatidylinositol glycan anchor biosynthesis class N) 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 expressed in the endoplasmic reticulum and transfers phosphoethanolamine (EtNP) to the first mannose of the GPI anchor. Two alternatively spliced variants, which encode an identical isoform, have been reported. [provided by RefSeq, Jul 2008]

PIGN Gene-Disease associations (from GenCC):

• multiple congenital anomalies-hypotonia-seizures syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, Orphanet, ClinGen, PanelApp Australia
• Fryns syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_benign. The variant received -4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.84).
• BP6: Variant 18-62114647-T-C is Benign according to our data. Variant chr18-62114647-T-C is described in ClinVar as Likely_benign. ClinVar VariationId is 539564.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIGN	NM_176787.5	c.1173-8A>G		splice_region_variant, intron_variant	Intron 14 of 30	ENST00000640252.2	NP_789744.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIGN	ENST00000640252.2	c.1173-8A>G		splice_region_variant, intron_variant	Intron 14 of 30	1	NM_176787.5	ENSP00000492233.1
PIGN	ENST00000400334.7	c.1173-8A>G		splice_region_variant, intron_variant	Intron 13 of 29	1		ENSP00000383188.2
PIGN	ENST00000638424.1	n.1173-8A>G		splice_region_variant, intron_variant	Intron 12 of 28	5		ENSP00000491963.1

Frequencies

GnomAD3 genomes AF: 0.0000592 AC: 9 AN: 151956 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000193

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000233 AC: 3 AN: 128604 AF XY: 0.0000292

Gnomad AFR exome AF: 0.000296

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000114

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000115 AC: 14 AN: 1218630 Hom.: 0 Cov.: 17 AF XY: 0.00000822 AC XY: 5 AN XY: 608500

African (AFR) AF: 0.000110 AC: 3 AN: 27232

American (AMR) AF: 0.00 AC: 0 AN: 30684

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23622

East Asian (EAS) AF: 0.0000289 AC: 1 AN: 34562

South Asian (SAS) AF: 0.00 AC: 0 AN: 71388

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46136

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4958

European-Non Finnish (NFE) AF: 0.00000970 AC: 9 AN: 928302

Other (OTH) AF: 0.0000193 AC: 1 AN: 51746

GnomAD4 genome AF: 0.0000592 AC: 9 AN: 152076 Hom.: 0 Cov.: 32 AF XY: 0.0000672 AC XY: 5 AN XY: 74350

African (AFR) AF: 0.000193 AC: 8 AN: 41520

American (AMR) AF: 0.00 AC: 0 AN: 15264

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10548

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67968

Other (OTH) AF: 0.00 AC: 0 AN: 2104

Alfa AF: 0.0000850 Hom.: 0

Bravo AF: 0.0000945

ClinVar

Significance: Likely benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple congenital anomalies-hypotonia-seizures syndrome 1 Benign:1

Dec 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

PIGN-related disorder Benign:1

Apr 06, 2021

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: no assertion criteria provided

Collection Method: clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.84
CADD	Benign	1.7
DANN	Benign	0.56
PhyloP100		1.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs76321419; hg19: chr18-59781880;