16-574503-G-T

Variant names:

• chr16-574503-G-T
• rs33997204
• NM_004204.5:c.429G>T
• PIGQ p.Leu143Leu

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_004204.5(PIGQ):​c.429G>T​(p.Leu143Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,455,318 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. Synonymous variant affecting the same amino acid position (i.e. L143L) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: PIGQ NM_004204.5 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -3.27
• Publications: 0 publications found

Genes affected

PIGQ (HGNC:14135): (phosphatidylinositol glycan anchor biosynthesis class Q) This gene is involved in the first step 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 gene encodes a N-acetylglucosaminyl transferase component that is part of the complex that catalyzes transfer of N-acetylglucosamine (GlcNAc) from UDP-GlcNAc to phosphatidylinositol (PI). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2012]

PIGQ Gene-Disease associations (from GenCC):

• developmental and epileptic encephalopathy, 77

  Inheritance: AR Classification: DEFINITIVE, STRONG, MODERATE, LIMITED Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P
• genetic developmental and epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000282907 (HGNC:):

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.87).
• BP7: Synonymous conserved (PhyloP=-3.27 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_004204.5. 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
	PIGQ	NM_004204.5	MANE Select	c.429G>T	p.Leu143Leu	synonymous	Exon 2 of 11	NP_004195.2
	PIGQ	NM_148920.4		c.429G>T	p.Leu143Leu	synonymous	Exon 2 of 10	NP_683721.1	Q9BRB3-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGQ	ENST00000321878.10	TSL:1 MANE Select	c.429G>T	p.Leu143Leu	synonymous	Exon 2 of 11	ENSP00000326674.6	Q9BRB3-2
	PIGQ	ENST00000026218.9	TSL:1	c.429G>T	p.Leu143Leu	synonymous	Exon 2 of 10	ENSP00000026218.5	Q9BRB3-1
	PIGQ	ENST00000470411.2	TSL:1	c.429G>T	p.Leu143Leu	synonymous	Exon 2 of 3	ENSP00000439650.1	Q9BRB3-3

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455318 Hom.: 0 Cov.: 40 AF XY: 0.00 AC XY: 0 AN XY: 723536

⚠️ 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: 33408

American (AMR) AF: 0.00 AC: 0 AN: 44236

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25984

East Asian (EAS) AF: 0.00 AC: 0 AN: 39492

South Asian (SAS) AF: 0.00 AC: 0 AN: 85342

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51166

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5688

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1109906

Other (OTH) AF: 0.00 AC: 0 AN: 60096

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.87
CADD	Benign	0.0060
DANN	Benign	0.44
PhyloP100		-3.3

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs33997204;

hg19: chr16-624503;