chr4-533822-A-C

Variant names:

• chr4-533822-A-C
• rs745840866
• NM_001127178.3:c.2576A>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_001127178.3(PIGG):​c.2576A>C​(p.Asn859Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,814 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. N859S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: PIGG NM_001127178.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.76
• Publications: 2 publications found

Genes affected

PIGG (HGNC:25985): (phosphatidylinositol glycan anchor biosynthesis class G (EMM blood group)) This gene encodes an enzyme involved in glycosylphosphatidylinositol-anchor biosynthesis. The encoded protein, which is localized to the endoplasmic reticulum, is involved in transferring ethanoloamine phosphate to mannose 2 of glycosylphosphatidylinositol species H7 to form species H8. Allelic variants of this gene have been associated with intellectual disability, hypotonia, and early-onset seizures. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2016]

PIGG Gene-Disease associations (from GenCC):

• intellectual disability, autosomal recessive 53

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.866

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001127178.3. 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
	PIGG	NM_001127178.3	MANE Select	c.2576A>C	p.Asn859Thr	missense	Exon 12 of 13	NP_001120650.1
	PIGG	NM_017733.5		c.2552A>C	p.Asn851Thr	missense	Exon 12 of 13	NP_060203.3
	PIGG	NM_001289051.2		c.2309A>C	p.Asn770Thr	missense	Exon 12 of 13	NP_001275980.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PIGG	ENST00000453061.7	TSL:1 MANE Select	c.2576A>C	p.Asn859Thr	missense	Exon 12 of 13	ENSP00000415203.2
	PIGG	ENST00000383028.8	TSL:1	c.2177A>C	p.Asn726Thr	missense	Exon 10 of 11	ENSP00000372494.4
	PIGG	ENST00000508144.1	TSL:1	n.191A>C		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD2 exomes AF: 0.0000119 AC: 3 AN: 251334 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: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461814 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727214

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000719 AC: 8 AN: 1111950

Other (OTH) AF: 0.0000331 AC: 2 AN: 60392

GnomAD4 genome Cov.: 34

ExAC AF: 0.0000330 AC: 4

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Intellectual disability, autosomal recessive 53 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Uncertain	0.099	D
BayesDel_noAF	Uncertain	-0.080
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.30	T
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Benign	0.020	T
MetaRNN	Pathogenic	0.87	D
MetaSVM	Benign	-0.58	T
MutationAssessor	Pathogenic	3.4	M
PhyloP100		8.8
PrimateAI	Uncertain	0.57	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Uncertain	0.48
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.63		Gain of sheet (P = 0.0344)
MVP		0.62
MPC		0.70
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.87
gMVP		0.90
Mutation Taster		=8/92	disease causing

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: rs745840866; hg19: chr4-527611;