rs1440750558

chrX-15321592-C-GchrX-15321592-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_002641.4(PIGA):c.1369G>C(p.Ala457Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000089 in 112,354 control chromosomes in the GnomAD database, with no homozygous occurrence. There are 1 hemizygotes in GnomAD. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A457T) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000089 (0 hom., 1 hem., cov: 23)
• Consequence: PIGA NM_002641.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.32

Genes affected

PIGA (HGNC:8957): (phosphatidylinositol glycan anchor biosynthesis class A) This gene encodes a protein required for synthesis of N-acetylglucosaminyl phosphatidylinositol (GlcNAc-PI), the first intermediate in the biosynthetic pathway of GPI anchor. The GPI anchor is a glycolipid found on many blood cells and which serves to anchor proteins to the cell surface. Paroxysmal nocturnal hemoglobinuria, an acquired hematologic disorder, has been shown to result from mutations in this gene. Alternate splice variants have been characterized. A related pseudogene is located on chromosome 12. [provided by RefSeq, Jun 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 3 uncertain in NM_002641.4
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PIGA	NM_002641.4	c.1369G>C	p.Ala457Pro	missense_variant	6/6	ENST00000333590.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PIGA	ENST00000333590.6	c.1369G>C	p.Ala457Pro	missense_variant	6/6	1	NM_002641.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000890 AC: 1 AN: 112354 Hom.: 0 Cov.: 23 AF XY: 0.0000290 AC XY: 1 AN XY: 34512

Gnomad AFR AF: 0.0000324

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: 0.00

GnomAD4 exome Cov.: 28

GnomAD4 genome AF: 0.00000890 AC: 1 AN: 112354 Hom.: 0 Cov.: 23 AF XY: 0.0000290 AC XY: 1 AN XY: 34512

Gnomad4 AFR AF: 0.0000324

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: 0.00

Bravo AF: 0.00000756

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.54
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Benign	0.18	T;T;T;.;.;.
FATHMM_MKL	Uncertain	0.96	D
M_CAP	Benign	0.019	T
MetaRNN	Uncertain	0.51	D;D;D;D;D;D
MetaSVM	Benign	-0.44	T
MutationAssessor	Pathogenic	2.9	M;M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-0.65	N;.;.;.;.;.
REVEL	Benign	0.15
Sift	Benign	0.20	T;.;.;.;.;.
Sift4G	Benign	0.20	T;T;.;T;T;.
Polyphen		1.0	D;D;.;.;D;.
Vest4		0.48
MutPred		0.54		Gain of loop (P = 0.0435);Gain of loop (P = 0.0435);.;.;.;.;
MVP		0.73
MPC		1.2
ClinPred		0.95	D
GERP RS		5.5
Varity_R		0.48
gMVP		0.96

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: rs1440750558; hg19: chrX-15339714;