chr17-36537175-G-A

Position:

• chr17-36537175-G-A

Variant summary

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

The NM_001346754.2(PIGW):​c.74G>A​(p.Gly25Glu) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PIGW NM_001346754.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.19

Genes affected

PIGW (HGNC:23213): (phosphatidylinositol glycan anchor biosynthesis class W) The protein encoded by this gene is an inositol acyltransferase that acylates the inositol ring of phosphatidylinositol. This occurs in the endoplasmic reticulum and is a step in the biosynthesis of glycosylphosphatidylinositol (GPI), which anchors many cell surface proteins to the membrane. Defects in this gene are a cause of the age-dependent epileptic encephalopathy West syndrome as well as a syndrome exhibiting hyperphosphatasia and cognitive disability (HPMRS5). [provided by RefSeq, Jul 2017]

MYO19 (HGNC:26234): (myosin XIX) Enables actin binding activity. Involved in regulation of cytokinesis and regulation of mitochondrial fission. Acts upstream of or within mitochondrion migration along actin filament. Located in cytosol and mitochondrial outer membrane. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

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	Protein	UniProt
PIGW	NM_001346754.2	c.74G>A	p.Gly25Glu	missense_variant	2/2	ENST00000614443.2	NP_001333683.1
PIGW	NM_001346755.2	c.74G>A	p.Gly25Glu	missense_variant	2/2		NP_001333684.1
PIGW	NM_178517.5	c.74G>A	p.Gly25Glu	missense_variant	2/2		NP_848612.2
MYO19	XM_047436823.1	c.-295-3071C>T		intron_variant			XP_047292779.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIGW	ENST00000614443.2	c.74G>A	p.Gly25Glu	missense_variant	2/2	1	NM_001346754.2	ENSP00000482202	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hyperphosphatasia with intellectual disability syndrome 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 07, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with PIGW-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glycine with glutamic acid at codon 25 of the PIGW protein (p.Gly25Glu). The glycine residue is moderately conserved and there is a moderate physicochemical difference between glycine and glutamic acid. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.41
BayesDel_addAF	Pathogenic	0.16	D
BayesDel_noAF	Uncertain	0.0
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.023	.;T;T
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.62
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.69	T;.;T
M_CAP	Benign	0.023	T
MetaRNN	Uncertain	0.70	D;D;D
MetaSVM	Uncertain	-0.20	T
MutationAssessor	Uncertain	2.6	.;M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Benign	0.46	T
Sift4G	Uncertain	0.023	D;D;D
Polyphen		0.99	.;D;D
Vest4		0.73, 0.73
MutPred		0.61		Loss of catalytic residue at C27 (P = 0.1365);Loss of catalytic residue at C27 (P = 0.1365);Loss of catalytic residue at C27 (P = 0.1365);
MVP		0.59
ClinPred		0.92	D
GERP RS		4.9
Varity_R		0.63
gMVP		0.78

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-34893024;