rs587784348

Positions:

• chr22-38113482-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP3

The ENST00000332509.8(PLA2G6):​c.2202+5G>A variant causes a splice donor 5th base, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PLA2G6 ENST00000332509.8 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 7.45

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Multiple lines of computational evidence support a deleterious effect 4: Cadd, dbscSNV1_ADA, dbscSNV1_RF, max_spliceai [when BayesDel_noAF, Dann was below the threshold]

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PLA2G6	NM_003560.4	c.2202+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000332509.8	NP_003551.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PLA2G6	ENST00000332509.8	c.2202+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_003560.4	ENSP00000333142	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Infantile neuroaxonal dystrophy Uncertain:1

Uncertain significance, criteria provided, single submitter

curation

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

May 02, 2023

The heterozygous c.2202+5G>A variant in PLA2G6 was identified by our study, in the compound heterozygous state with a pathogenic variant (ClinVar Variation ID: 159749), in one individual with generalized muscle weakness, hypotonia, delayed speech and language development, gait imbalance, and inability to walk. Trio exome analysis revealed that this variant was in trans with a pathogenic variant (ClinVar Variation ID: 159749). The c.2202+5G>A variant in PLA2G6 has not been previously reported in individuals with neurodegeneration with brain iron accumulation-2A. This variant was absent from large population studies. This variant has also been reported in ClinVar (Variation ID: 159760) and has been interpreted as a variant of uncertain significance by the University of Chicago Genetic Services Laboratory and Illumina. This variant is located in the 5' splice region. Computational tools do suggest an impact to splicing. However, this information is not predictive enough to determine pathogenicity. In summary, while there is some suspicion for a pathogenic role, the clinical significance of this variant is uncertain. ACMG/AMP Criteria applied: PM2_Supporting, PM3, PP3 (Richards 2015). -

Iron accumulation in brain Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Feb 08, 2013

- -

PLA2G6-associated neurodegeneration Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Feb 06, 2020

The PLA2G6 c.2202+5G>A variant is a splice region variant. A literature search was performed for the gene and cDNA change. No publications were found based on this search. This variant is not found in the Genome Aggregation Database in a region of good sequencing coverage, so the variant is presumed to be rare. Based on the limited evidence, the c.2202+5G>A variant is classified as a variant of unknown significance for PLA2G6-associated neurodegeneration. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	29
DANN	Benign	0.97

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.88		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.52		Position offset: -46
DS_DL_spliceai		0.88		Position offset: 5

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

Publications

LitVar

Other links and lift over

dbSNP: rs587784348; hg19: chr22-38509489;