chr20-45416269-C-T

Position:

• chr20-45416269-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_015937.6(PIGT):​c.113C>T​(p.Pro38Leu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PIGT NM_015937.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.92

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]

LOC107985405 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.919

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIGT	NM_015937.6	c.113C>T	p.Pro38Leu	missense_variant	1/12	ENST00000279036.12
LOC107985405	XR_001754640.2	n.719G>A		non_coding_transcript_exon_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIGT	ENST00000279036.12	c.113C>T	p.Pro38Leu	missense_variant	1/12	1	NM_015937.6	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1442294 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 715796

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Multiple congenital anomalies-hypotonia-seizures syndrome 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 07, 2023

ClinVar contains an entry for this variant (Variation ID: 1945195). This variant has not been reported in the literature in individuals affected with PIGT-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 38 of the PIGT protein (p.Pro38Leu). 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 PIGT 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.060
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.47	T;.;.;.;.;.;.;.;.;.;.;.;.;.;.
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.14	D
MetaRNN	Pathogenic	0.92	D;D;D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Uncertain	-0.025	T
MutationAssessor	Pathogenic	3.7	H;H;H;H;.;.;.;.;.;.;.;.;.;H;.
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Pathogenic	-8.3	D;N;D;D;.;.;.;.;.;.;.;.;.;D;.
REVEL	Uncertain	0.42
Sift	Uncertain	0.0010	D;D;D;D;.;.;.;.;.;.;.;.;.;D;.
Sift4G	Uncertain	0.0070	D;D;D;D;.;.;.;.;.;.;.;.;.;.;.
Polyphen		1.0	D;D;.;.;.;.;.;.;.;.;.;.;.;D;.
Vest4		0.72
MutPred		0.85		Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);Loss of catalytic residue at P38 (P = 0.0645);.;
MVP		0.76
MPC		0.51
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.0
Varity_R		0.84
gMVP		0.83

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: rs1218912444; hg19: chr20-44044909;