1-77166809-G-T

Variant names:

• chr1-77166809-G-T
• rs374050300
• NM_005482.3:c.397C>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_005482.3(PIGK):​c.397C>A​(p.Arg133Arg) variant causes a synonymous change. The variant allele was found at a frequency of 0.0000014 in 1,432,256 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PIGK NM_005482.3 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.25
• Publications: 0 publications found

Genes affected

PIGK (HGNC:8965): (phosphatidylinositol glycan anchor biosynthesis class K) This gene encodes a member of the cysteine protease family C13 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 a member of the multisubunit enzyme, GPI transamidase and is thought to be its enzymatic component. GPI transamidase mediates GPI anchoring in the endoplasmic reticulum, by catalyzing the transfer of fully assembled GPI units to proteins. [provided by RefSeq, Jul 2008]

PIGK Gene-Disease associations (from GenCC):

• neurodevelopmental disorder with hypotonia and cerebellar atrophy, with or without seizures

  Inheritance: AR Classification: STRONG, MODERATE Submitted by: PanelApp Australia, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.47).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PIGK	NM_005482.3	c.397C>A	p.Arg133Arg	synonymous_variant	Exon 5 of 11	ENST00000370812.8	NP_005473.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PIGK	ENST00000370812.8	c.397C>A	p.Arg133Arg	synonymous_variant	Exon 5 of 11	1	NM_005482.3	ENSP00000359848.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000140 AC: 2 AN: 1432256 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 713444

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 32408

American (AMR) AF: 0.00 AC: 0 AN: 41706

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25704

East Asian (EAS) AF: 0.00 AC: 0 AN: 39354

South Asian (SAS) AF: 0.00 AC: 0 AN: 82662

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53312

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5712

European-Non Finnish (NFE) AF: 0.00000183 AC: 2 AN: 1092022

Other (OTH) AF: 0.00 AC: 0 AN: 59376

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.47
CADD	Benign	9.6
DANN	Benign	0.45
PhyloP100		4.3
Mutation Taster		=100/0	polymorphism

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: rs374050300; hg19: chr1-77632494;