rs774753616

Variant names:

• chr20-45419351-G-A
• rs774753616
• NM_015937.6:c.550G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM2 PP3_Moderate PP5

The NM_015937.6(PIGT):​c.550G>A​(p.Glu184Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,982 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.000013 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: PIGT NM_015937.6 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 9.35
• Publications: 5 publications found

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]

PIGT Gene-Disease associations (from GenCC):

• multiple congenital anomalies-hypotonia-seizures syndrome 3

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae), G2P

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.895
• PP5: Variant 20-45419351-G-A is Pathogenic according to our data. Variant chr20-45419351-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 547166.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_015937.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGT	NM_015937.6	MANE Select	c.550G>A	p.Glu184Lys	missense	Exon 4 of 12	NP_057021.2
	PIGT	NM_001184728.3		c.382G>A	p.Glu128Lys	missense	Exon 3 of 11	NP_001171657.1	Q969N2-5
	PIGT	NM_001184729.3		c.550G>A	p.Glu184Lys	missense	Exon 4 of 11	NP_001171658.1	Q969N2-6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGT	ENST00000279036.12	TSL:1 MANE Select	c.550G>A	p.Glu184Lys	missense	Exon 4 of 12	ENSP00000279036.6	Q969N2-1
	PIGT	ENST00000372689.9	TSL:1	c.550G>A	p.Glu184Lys	missense	Exon 4 of 11	ENSP00000361774.4	Q969N2-6
	PIGT	ENST00000639235.1	TSL:1	c.439G>A	p.Glu147Lys	missense	Exon 3 of 8	ENSP00000492498.1	A0A1W2PRH2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152214 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000241

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251190 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461768 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727178

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53398

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1111948

Other (OTH) AF: 0.00 AC: 0 AN: 60394

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152214 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74364

African (AFR) AF: 0.0000241 AC: 1 AN: 41450

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4838

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000987 Hom.: 0

Bravo AF: 0.0000151

ExAC AF: 0.0000165 AC: 2

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
2	-	-	Multiple congenital anomalies-hypotonia-seizures syndrome 3 (2)
-	1	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.27	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	34
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.57	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.90	D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Pathogenic	3.8	H
PhyloP100		9.4
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.6	D
REVEL	Pathogenic	0.72
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.98
MVP		0.86
MPC		0.51
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.86
gMVP		0.92
Mutation Taster		=4/96	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: rs774753616; hg19: chr20-44047991; COSMIC: COSV54125561; COSMIC: COSV54125561;