rs121908680

Positions:

• chr22-38112212-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_003560.4(PLA2G6):​c.2370T>G​(p.Tyr790Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000122 in 1,609,764 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 0.000059 (0 hom., cov: 33)
  • Exomes 𝑓: 0.00013 (0 hom.)
• Consequence: PLA2G6 NM_003560.4 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:22 U:1
• Conservation: PhyloP100: 0.103

Genes affected

PLA2G6 (HGNC:9039): (phospholipase A2 group VI) The protein encoded by this gene is an A2 phospholipase, a class of enzyme that catalyzes the release of fatty acids from phospholipids. The encoded protein may play a role in phospholipid remodelling, arachidonic acid release, leukotriene and prostaglandin synthesis, fas-mediated apoptosis, and transmembrane ion flux in glucose-stimulated B-cells. Several transcript variants encoding multiple isoforms have been described, but the full-length nature of only three of them have been determined to date. [provided by RefSeq, Dec 2010]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 6 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-38112212-A-C is Pathogenic according to our data. Variant chr22-38112212-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 6195.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=19, Likely_pathogenic=1, Uncertain_significance=1}. Variant chr22-38112212-A-C is described in Lovd as [Pathogenic]. Variant chr22-38112212-A-C is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PLA2G6	NM_003560.4	c.2370T>G	p.Tyr790Ter	stop_gained	17/17	ENST00000332509.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PLA2G6	ENST00000332509.8	c.2370T>G	p.Tyr790Ter	stop_gained	17/17	1	NM_003560.4	P3

Frequencies

GnomAD3 genomes AF: 0.0000591 AC: 9 AN: 152158 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.0000483

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000822 AC: 20 AN: 243312 Hom.: 0 AF XY: 0.0000759 AC XY: 10 AN XY: 131812

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000148

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000337

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.000128

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000129 AC: 188 AN: 1457606 Hom.: 0 Cov.: 32 AF XY: 0.000130 AC XY: 94 AN XY: 724812

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000113

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000702

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.000150

Gnomad4 OTH exome AF: 0.000133

GnomAD4 genome AF: 0.0000591 AC: 9 AN: 152158 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74322

Gnomad4 AFR AF: 0.0000483

Gnomad4 AMR AF: 0.0000655

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000111 Hom.: 0

Bravo AF: 0.0000982

TwinsUK AF: 0.000270 AC: 1

ALSPAC AF: 0.000519 AC: 2

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.0000495 AC: 6

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:22 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Infantile neuroaxonal dystrophy Pathogenic:9

Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The stop gained c.2370T>G (p.Y790*) in PLA2G6 (NM_003560.4) has been observed in the homozygous and compound heterozygous state in individuals affected with PLA2G6-related conditions (Morgan NV et al; Blake RB et al). Experimental studies have shown that this variant disrupts PLA2G6 enzymatic activity in vitro (Engel LA et al). The observed variant has been reported to ClinVar as Conflicting Interpretations Of Pathogenicity. This variant is predicted to cause loss of normal protein function through protein truncation. For these reasons, this variant has been classified as Pathogenic -
Pathogenic, no assertion criteria provided	literature only	OMIM	Jul 01, 2006	- -
Pathogenic, criteria provided, single submitter	clinical testing	Centogene AG - the Rare Disease Company	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Institute of Human Genetics Munich, Klinikum Rechts Der Isar, TU München	Dec 27, 2018	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genomic Research Center, Shahid Beheshti University of Medical Sciences	Dec 03, 2017	- -
Pathogenic, no assertion criteria provided	curation	Department Of Genetics, Sultan Qaboos University Hospital, Sultan Qaboos University	Dec 30, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 04, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Sep 01, 2017	This variant has been previously reported as disease-causing and was found twice in our laboratory with another variant in affected individuals: a 2-year-old male with regression, hearing loss, hypotonia, failure to thrive, cerebellar atrophy, vision loss; a 5-year-old female with regression, dystonia, epilepsy, microcephaly, failure to thrive, cerebellar atrophy. Heterozygotes would be expected to be asymptomatic carriers. -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 29, 2024	This sequence change creates a premature translational stop signal (p.Tyr790*) in the PLA2G6 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 17 amino acid(s) of the PLA2G6 protein. This variant is present in population databases (rs121908680, gnomAD 0.01%). This premature translational stop signal has been observed in individuals with clinical features of PLA2G6-related conditions (PMID: 16783378, 27378808; Invitae). ClinVar contains an entry for this variant (Variation ID: 6195). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects PLA2G6 function (PMID: 20886109). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Jul 01, 2022	PLA2G6: PVS1, PM2 -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 30, 2021	Functional studies demonstrate that this variant significantly impairs catalytic activity of the PLA2G6 protein (Engel et al., 2010); Nonsense variant in the C-terminus predicted to result in protein truncation, as the last 17 amino acids are lost, and other loss-of-function variants have been reported downstream in the Human Gene Mutation Database (Stenson et al., 2014); This variant is associated with the following publications: (PMID: 18359254, 20886109, 16783378, 27378808, 28600779, 24800972, 18443314, 24847269, 18570303, 24745848, 30537300, 30340910, 20619503, 33101984, 31589614) -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Oct 22, 2019	- -

Neurodegeneration with brain iron accumulation 2B Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jan 01, 2018	This variant was determined to be pathogenic according to ACMG Guidelines, 2015 [PMID:25741868]. This variant has been previously reported as disease-causing [PMID 16783378, 27378808, 20886109] -
Pathogenic, criteria provided, single submitter	clinical testing	Neuberg Centre For Genomic Medicine, NCGM	-	The stop gained variant c.2370T>G (p.Tyr790Ter) in PLA2G6 gene has been reported in at least eight studies in a total of 11 probands with PLA2G6-associated neurodegeneration (Morgan NV et.al.,2006). Functional studies demonstrate that this variant significantly impairs catalytic activity of the PLA2G6 protein (Engel et al., 2010). This variant has been reported to the ClinVar database as Pathogenic.The variant is novel (not in any individuals) in 1000 Genomes and allele frequency of 0.009102% is reported in gnomAD. The nucleotide change in PLA2G6 is predicted as conserved by PhyloP across 100 vertebrates.For these reasons, this variant has been classified as Pathogenic -

PLA2G6-associated neurodegeneration Pathogenic:2

Pathogenic, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 24, 2023	The p.Tyr790Ter variant in PLA2G6 has been reported in >10 individuals with PLA2G6-associated neurodegeneration (PMID: 33101984, 18359254, 18799783, 27378808, 30293248, 28716262, 16783378, 28600779, 30340910, 32860008, 34602496, 35122944, Miryounesi 2018, 30868093, 34622992, 30537300, 33619735, 29859652, Silva 2014), segregated with disease in 2 affected relatives from 2 families (PMID: 28716262, 31196701), and has been identified in 0.02% (19/125174) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs121908680). Although this variant has been seen in the general population in a heterozygous state, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID#: 6195) and has been interpreted as pathogenic and likely pathogenic by multiple submitters, as well as a variant of uncertain significance by the Institute for Medical Genetics and Human Genetics (Charité - Universitätsmedizin Berlin). Of the 26 affected individuals, 12 of those were homozygotes, and 5 were compound heterozygotes that carried reported likely pathogenic variants in trans or with unknown phase, which increases the likelihood that the p.Tyr790Ter variant is pathogenic (Variant ID: 159741, 265448; PMID: 33101984, 18359254, 18799783, 27378808, 30293248, 28716262, 16783378, 28600779, 30340910, 32860008, 34602496, 35122944, Miryounesi 2018). In vitro functional studies provide some evidence that the p.Tyr790Ter variant impacts protein function (PMID: 20886109, 35122944). However, these types of assays may not accurately represent biological function. This nonsense variant leads to a premature termination codon at position 790. This alteration occurs within the last exon and is more likely to escape nonsense mediated decay (NMD) and result in a truncated protein. Loss of function of the PLA2G6 gene is an established disease mechanism in autosomal recessive PLA2G6-associated neurodegeneration. In summary, this variant meets criteria to be classified as pathogenic for autosomal recessive PLA2G6-associated neurodegeneration. ACMG/AMP Criteria applied: PVS1_moderate, PM3_very-strong, PP1, PS3_moderate (Richards 2015). -
Pathogenic, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Oct 18, 2018	The PLA2G6 c.2370T>G (p.Tyr790Ter) variant is a stop-gained variant and has been reported in at least eight studies in a total of 11 probands with PLA2G6-associated neurodegeneration, including in at least five in a homozygous state, in five in a compound heterozygous state, and in one in a heterozygous state (Morgan et al. 2006; Carrilho et al. 2008; Gregory et al. 2008; Pinto et al. 2010; Paisan-Ruiz 2012; Illingworth et al. 2014; Blake et al. 2016; Erro et al. 2016). Of note, another variant, c.2370_2371delTG, which also results in p.Tyr790Ter, has been reported in both a homozygous and compound heterozygous state in other probands. Control data are not available for the p.Tyr790Ter variant, which is reported at a frequency of 0.000148 in the Latino from the Genome Aggregation Database. In vitro studies examining the catalytic function of the p.Tyr790Ter variant demonstrated <10% phospholipase activity compared to wildtype in the presence of two different substrates (Engel et al. 2010). Based on the collective evidence, the p.Tyr790Ter variant is classified as pathogenic for PLA2G6-associated neurodegeneration. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

Neurodegeneration with brain iron accumulation Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 24, 2022

Variant summary: PLA2G6 c.2370T>G (p.Tyr790X) located in the last exon results in a premature termination codon, predicted to cause a truncation of the encoded protein, which is a commonly known mechanism for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 8.2e-05 in 243312 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in PLA2G6 (8.2e-05 vs 0.00085), allowing no conclusion about variant significance. c.2370T>G has been reported in the literature as homozygous and compound heterozygous genotypes in multiple individuals affected with features of PLA2G6-associated neurodegeneration (PLAN), predominantly as infantile neuroaxonal dystrophy (INAD) (example, Carrilho_2008, Gregory_2008, Darling_2019). These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal Phospholipase and lysophospholipase catalytic activities in-vitro (example, Engel_2010). Twelve clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Inborn genetic diseases Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 20, 2016

- -

PLA2G6-related disorder Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Sep 23, 2023

The PLA2G6 c.2370T>G variant is predicted to result in premature protein termination (p.Tyr790*). This variant has been reported in the homozygous or compound heterozygous state in multiple individuals with infantile neuroaxonal dystrophy or neurodegeneration with brain iron accumulation (see for example, Gitiaux et al. 2018. PubMed ID: 29859652; AlBanji et al. 2020. PubMed ID: 33101984; Table S1, Brunet et al. 2021. PubMed ID: 33619735). An in vitro experimental study suggests this variant decreases enzymatic activity to less that 10% of wildtype activity (Figure 3, Engel et al. 2010. PubMed ID: 20886109). This variant is reported in 0.015% of alleles in individuals of European (Non-Finnish) descent in gnomAD (http://gnomad.broadinstitute.org/variant/22-38508219-A-C). Nonsense variants in PLA2G6 are expected to be pathogenic. This variant is interpreted as pathogenic. -

Abnormality of the nervous system Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Kariminejad - Najmabadi Pathology & Genetics Center

Jul 10, 2021

- -

Iron accumulation in brain Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Mar 17, 2014

- -

Infantile neuroaxonal dystrophy;C1857747:Neurodegeneration with brain iron accumulation 2B;C2751842:Autosomal recessive Parkinson disease 14 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Oct 31, 2018

- -

Autism;C0036572:Seizure Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Institute for Medical Genetics and Human Genetics, Charité - Universitätsmedizin Berlin

-

We were able to detect the known pathogenic mutation c.2370T>G in the PLA2G6 gene in the patient in a heterozygous state. The variant was also detected in the mother of the patient in heterozygous state. The PLA2G6 gene codes for phospholipase A2 of group 6 (MIM *603604). Biallelic pathogenic sequence variants in PLA2G6 have been described with three clinical manifestations of autosomal recessively inherited PLA2G6-associated neurodegeneration: 1) infantile neuroaxonal dystrophy (INAD, MIM: 256600), 2) neurodegeneration with iron accumulation in the brain (NBIA, MIM: 610217) and 3) PLA2G6-dependent dystonia parkinsonism (MIM: 612953). Clinical symptoms include psychomotor regression, symmetrical pyramidal trajectory signs, pronounced trunk hypotension, spastic quadriplegia, visual disturbances and dementia. The clinical course may be variable. The above variation leads to the formation of a premature stop codon and thus most likely to the premature termination of protein biosynthesis. The variant has already been reported in numerous patients in homozygous or compound-heterozygous condition (HGMD: CM063050). The sequence variant is listed in gnomAD 25x in heterozygous state and occurs in the European subpopulation with an allele frequency of 0.015%. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	33
DANN	Uncertain	0.98
Eigen	Benign	0.0057
Eigen_PC	Benign	-0.30
FATHMM_MKL	Benign	0.74	D
MutationTaster	Benign	1.0	A;A;A;A
Vest4		0.73
GERP RS		-5.9

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs121908680; hg19: chr22-38508219;