1-172441988-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Moderate PP5_Moderate

The NM_153747.2(PIGC):c.635T>C(p.Leu212Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,242 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L212R) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: PIGC NM_153747.2 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 8.79

Genes affected

PIGC (HGNC:8960): (phosphatidylinositol glycan anchor biosynthesis class C) This gene encodes an endoplasmic reticulum associated protein that is involved in glycosylphosphatidylinositol (GPI) lipid anchor biosynthesis. The GPI lipid anchor is a glycolipid found on many blood cells and serves to anchor proteins to the cell surface. The encoded protein is one subunit of the GPI N-acetylglucosaminyl (GlcNAc) transferase that transfers GlcNAc to phosphatidylinositol (PI) on the cytoplasmic side of the endoplasmic reticulum. Two alternatively spliced transcripts that encode the same protein have been found for this gene. A pseudogene on chromosome 11 has also been characterized. [provided by RefSeq, Jul 2008]

C1orf105 (HGNC:29591): (chromosome 1 open reading frame 105)

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a chain Phosphatidylinositol N-acetylglucosaminyltransferase subunit C (size 296) in uniprot entity PIGC_HUMAN there are 6 pathogenic changes around while only 2 benign (75%) in NM_153747.2
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.937
• PP5: Variant 1-172441988-A-G is Pathogenic according to our data. Variant chr1-172441988-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 471154.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr1-172441988-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIGC	NM_153747.2	c.635T>C	p.Leu212Pro	missense_variant	2/2	ENST00000344529.5
C1orf105	NM_139240.4	c.22-3085A>G		intron_variant		ENST00000367727.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIGC	ENST00000344529.5	c.635T>C	p.Leu212Pro	missense_variant	2/2	1	NM_153747.2	P1
C1orf105	ENST00000367727.9	c.22-3085A>G		intron_variant		1	NM_139240.4	P1
PIGC	ENST00000484368.1	n.96+2000T>C		intron_variant, non_coding_transcript_variant		1
PIGC	ENST00000367728.1	c.635T>C	p.Leu212Pro	missense_variant	1/1			P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.00

Gnomad OTH AF: 0.000478

GnomAD4 exome Cov.: 39

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152242 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74382

Gnomad4 AFR AF: 0.00

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: 0.00

Gnomad4 OTH AF: 0.000478

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Glycosylphosphatidylinositol biosynthesis defect 16 Pathogenic:2

Pathogenic, no assertion criteria provided	literature only	OMIM	Dec 21, 2017	- -
Likely pathogenic, criteria provided, single submitter	curation	SIB Swiss Institute of Bioinformatics	Oct 15, 2018	This variant is interpreted as Likely Pathogenic, for Glycosylphosphatidylinositol biosynthesis defect 16, autosomal recessive. The following ACMG Tag(s) were applied: PP3 => Multiple lines of computational evidence support a deleterious effect on the gene or gene product. PM2 => Absent from controls (or at extremely low frequency if recessive) in Exome Sequencing Project, 1000 Genomes Project, or Exome Aggregation Consortium. PS3-Moderate => PS3 downgraded in strength to Moderate (https://www.ncbi.nlm.nih.gov/pubmed/27694521). PM3-Supporting => PM3 downgraded in strength to Supporting. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
Cadd	Pathogenic	28
Dann	Pathogenic	1.0
DEOGEN2	Benign	0.22	T;T
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Pathogenic	0.98	D
M_CAP	Uncertain	0.12	D
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Uncertain	-0.16	T
MutationAssessor	Pathogenic	2.9	M;M
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Pathogenic	0.79
Sift	Pathogenic	0.0	D;D
Sift4G	Uncertain	0.0020	D;D
Polyphen		1.0	D;D
Vest4		0.99
MutPred		0.81		Loss of helix (P = 0.0041);Loss of helix (P = 0.0041);
MVP		0.79
MPC		0.74
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.97
gMVP		0.95

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: rs1553259602; hg19: chr1-172411128;