17-39685992-T-C

Variant names:

• chr17-39685992-T-C
• rs146132289
• NM_033419.5:c.209A>G

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_033419.5(PGAP3):​c.209A>G​(p.Tyr70Cys) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,460,912 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y70F) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PGAP3 NM_033419.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.03
• Publications: 0 publications found

Genes affected

PGAP3 (HGNC:23719): (post-GPI attachment to proteins phospholipase 3) This gene encodes a glycosylphosphatidylinositol (GPI)-specific phospholipase that primarily localizes to the Golgi apparatus. This ubiquitously expressed gene is predicted to encode a seven-transmembrane protein that removes unsaturated fatty acids from the sn-2 position of GPI. The remodeling of the constituent fatty acids on GPI is thought to be important for the proper association between GPI-anchored proteins and lipid rafts. The tethering of proteins to plasma membranes via posttranslational GPI-anchoring is thought to play a role in protein sorting and trafficking. Mutations in this gene cause an autosomal recessive form of neurologic hyperphosphatasia with cognitive disability (HPMRS4). Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2017]

PGAP3 Gene-Disease associations (from GenCC):

• hyperphosphatasia with intellectual disability syndrome 4

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, ClinGen, Labcorp Genetics (formerly Invitae)
• hyperphosphatasia-intellectual disability syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_033419.5. 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
	PGAP3	NM_033419.5	MANE Select	c.209A>G	p.Tyr70Cys	missense	Exon 2 of 8	NP_219487.3
	PGAP3	NM_001291728.2		c.209A>G	p.Tyr70Cys	missense	Exon 2 of 7	NP_001278657.1
	PGAP3	NM_001291726.2		c.209A>G	p.Tyr70Cys	missense	Exon 2 of 7	NP_001278655.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	PGAP3	ENST00000300658.9	TSL:1 MANE Select	c.209A>G	p.Tyr70Cys	missense	Exon 2 of 8	ENSP00000300658.4
	PGAP3	ENST00000429199.6	TSL:2	c.209A>G	p.Tyr70Cys	missense	Exon 2 of 7	ENSP00000415765.2
	PGAP3	ENST00000378011.8	TSL:2	c.209A>G	p.Tyr70Cys	missense	Exon 2 of 7	ENSP00000367250.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1460912 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726718

⚠️ 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: 33456

American (AMR) AF: 0.00 AC: 0 AN: 44686

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39658

South Asian (SAS) AF: 0.00 AC: 0 AN: 86240

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53316

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5762

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111368

Other (OTH) AF: 0.00 AC: 0 AN: 60324

⚠️ 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.: 31

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.87	D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.97	D
M_CAP	Uncertain	0.13	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Uncertain	0.38	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		7.0
PrimateAI	Uncertain	0.78	T
PROVEAN	Pathogenic	-8.2	D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.91		Loss of ubiquitination at K69 (P = 0.2139)
MVP		0.64
MPC		1.2
ClinPred		1.0	D
GERP RS		5.2
Varity_R		0.95
gMVP		0.91
Mutation Taster		=11/89	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs146132289; hg19: chr17-37842245;