X-15331768-G-A

Variant names:

• chrX-15331768-G-A
• rs199422233
• NM_002641.4:c.163C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_002641.4(PIGA):​c.163C>T​(p.Gln55*) variant causes a stop gained change involving the alteration of a conserved nucleotide. 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 Pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 23)
• Consequence: PIGA NM_002641.4 stop_gained
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 9.50
• Publications: 1 publications found

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]

PIGA Gene-Disease associations (from GenCC):

• multiple congenital anomalies-hypotonia-seizures syndrome 2

  Inheritance: XL Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: G2P, Illumina, Labcorp Genetics (formerly Invitae), Orphanet
• infantile spasms

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• malignant migrating partial seizures of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• ferro-cerebro-cutaneous syndrome

  Inheritance: XL Classification: SUPPORTIVE Submitted by: Orphanet
• paroxysmal nocturnal hemoglobinuria

  Inheritance: Unknown Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-15331768-G-A is Pathogenic according to our data. Variant chrX-15331768-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 9961.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_002641.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGA	NM_002641.4	MANE Select	c.163C>T	p.Gln55*	stop_gained	Exon 2 of 6	NP_002632.1
	PIGA	NM_001440789.1		c.163C>T	p.Gln55*	stop_gained	Exon 2 of 7	NP_001427718.1
	PIGA	NR_033835.1		n.279C>T		non_coding_transcript_exon	Exon 2 of 6

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGA	ENST00000333590.6	TSL:1 MANE Select	c.163C>T	p.Gln55*	stop_gained	Exon 2 of 6	ENSP00000369820.3
	PIGA	ENST00000542278.6	TSL:5	c.163C>T	p.Gln55*	stop_gained	Exon 2 of 6	ENSP00000442653.2
	PIGA	ENST00000482148.6	TSL:5	c.163C>T	p.Gln55*	stop_gained	Exon 2 of 5	ENSP00000489528.1

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

Alfa AF: 0.00 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Paroxysmal nocturnal hemoglobinuria Pathogenic:1

Dec 15, 1995

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.73	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	37
DANN	Uncertain	1.0
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		9.5
Vest4		0.94
GERP RS		6.1
Mutation Taster		=2/198	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199422233; hg19: chrX-15349890;