Genetic Variant PNPLA2:p.Arg221Cys (chr11-822571-C-T) – ACMG Classification: Uncertain_significance (4 pts)

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_020376.4(PNPLA2):c.661C>T(p.Arg221Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,613,954 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 (★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000082 ( 0 hom. )

Consequence

PNPLA2
NM_020376.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 3.40

Variant links:

Genes affected

PNPLA2 (HGNC:30802): (patatin like phospholipase domain containing 2) This gene encodes an enzyme which catalyzes the first step in the hydrolysis of triglycerides in adipose tissue. Mutations in this gene are associated with neutral lipid storage disease with myopathy. [provided by RefSeq, Jul 2010]

PNPLA2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.897

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNPLA2	NM_020376.4 link	c.661C>T	p.Arg221Cys	missense_variant	Exon 5 of 10	ENST00000336615.9	NP_065109.1	Q96AD5-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
PNPLA2	ENST00000336615.9 link	c.661C>T	p.Arg221Cys	missense_variant	Exon 5 of 10	1	NM_020376.4	ENSP00000337701.4	Q96AD5-1
PNPLA2	ENST00000525250.5 link	n.1267C>T		non_coding_transcript_exon_variant	Exon 3 of 6	2
PNPLA2	ENST00000531923.1 link	n.556C>T		non_coding_transcript_exon_variant	Exon 1 of 2	2

Frequencies

GnomAD3 genomes

AF:

0.0000328

AC:

AN:

152218

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000192

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000441

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000119

AC:

AN:

251326

Hom.:

AF XY:

0.0000221

AC XY:

AN XY:

135870

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000821

AC:

AN:

1461618

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

727124

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000464

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152336

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74504

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000340

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Neutral lipid storage myopathy

Uncertain:1

Jun 04, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 221 of the PNPLA2 protein (p.Arg221Cys). This variant is present in population databases (rs538014722, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with PNPLA2-related conditions. ClinVar contains an entry for this variant (Variation ID: 534194). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.81

BayesDel_addAF

Pathogenic

0.26

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.88

Eigen

Uncertain

0.32

Eigen_PC

Benign

0.13

FATHMM_MKL

Uncertain

0.92

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.52

MetaRNN

Pathogenic

0.90

MetaSVM

Uncertain

0.40

MutationAssessor

Pathogenic

3.0

PrimateAI

Uncertain

0.71

PROVEAN

Uncertain

-3.6

REVEL

Pathogenic

0.76

Sift

Uncertain

0.0080

Sift4G

Uncertain

0.0040

Polyphen

1.0

Vest4

0.93

MutPred

0.63

Loss of MoRF binding (P = 0.0094);

MVP

0.92

MPC

0.98

ClinPred

0.97

GERP RS

2.1

Varity_R

0.38

gMVP

0.84

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over