chr18-62082682-G-A

Position:

chr18-62082682-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_176787.5(PIGN):c.2567C>T(p.Ser856Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000019 in 1,528,862 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. S856S) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

PIGN
NM_176787.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 8.40

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIGN	NM_176787.5 linkuse as main transcript	c.2567C>T	p.Ser856Leu	missense_variant	28/31	ENST00000640252.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIGN	ENST00000640252.2 linkuse as main transcript	c.2567C>T	p.Ser856Leu	missense_variant	28/31	1	NM_176787.5	P1

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151956

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000242

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

GnomAD4 exome

AF:

0.0000196

AC:

AN:

1376906

Hom.:

Cov.:

AF XY:

0.0000264

AC XY:

AN XY:

681310

show subpopulations

Gnomad4 AFR exome

AF:

0.0000637

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000273

Gnomad4 SAS exome

AF:

0.0000513

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000151

Gnomad4 OTH exome

AF:

0.0000523

GnomAD4 genome

AF:

0.0000132

AC:

AN:

151956

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74218

show subpopulations

Gnomad4 AFR

AF:

0.0000242

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000264

ExAC

AF:

0.00000862

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Inborn genetic diseases

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 06, 2023

The c.2567C>T (p.S856L) alteration is located in exon 28 (coding exon 25) of the PIGN gene. This alteration results from a C to T substitution at nucleotide position 2567, causing the serine (S) at amino acid position 856 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Multiple congenital anomalies-hypotonia-seizures syndrome 1

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 24, 2022

This sequence change replaces serine, which is neutral and polar, with leucine, which is neutral and non-polar, at codon 856 of the PIGN protein (p.Ser856Leu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with PIGN-related conditions. ClinVar contains an entry for this variant (Variation ID: 451887). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PIGN protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Jun 28, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.22

BayesDel_addAF

Uncertain

0.13

BayesDel_noAF

Uncertain

-0.050

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.19

T;.;T;T;T;.;.;.;.;.;T;.;.;T;.;T;.;.

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.99

.;.;.;.;.;.;D;.;D;D;.;D;D;.;D;D;D;D

M_CAP

Benign

0.074

MetaRNN

Uncertain

0.62

D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D;D

MetaSVM

Benign

-0.50

MutationAssessor

Uncertain

2.9

M;.;M;M;M;.;.;.;.;.;M;.;.;M;.;M;.;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Uncertain

0.58

PROVEAN

Uncertain

-3.1

.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.

REVEL

Uncertain

0.33

Sift

Uncertain

0.020

.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.

Sift4G

Uncertain

0.026

.;.;.;D;.;.;.;.;.;.;D;.;.;.;.;.;.;.

Polyphen

1.0

D;.;D;D;D;.;.;.;.;.;D;.;.;D;.;D;.;.

Vest4

0.70, 0.70

MutPred

0.53

Loss of disorder (P = 0.0349);.;Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);.;.;Loss of disorder (P = 0.0349);.;.;Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);.;Loss of disorder (P = 0.0349);.;Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);Loss of disorder (P = 0.0349);

MVP

0.84

MPC

0.14

ClinPred

0.94

GERP RS

5.7

Varity_R

0.25

gMVP

0.31

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.040

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over