NM_020376.4:c.1433A>G

Variant names:

• chr11-824780-A-G
• rs929233099
• NM_020376.4:c.1433A>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_020376.4(PNPLA2):​c.1433A>G​(p.Gln478Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000115 in 1,386,332 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Q478Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: PNPLA2 NM_020376.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.66
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• neutral lipid storage myopathy

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, ClinGen, G2P, Labcorp Genetics (formerly Invitae), Orphanet

ENSG00000255108 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.1300596).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNPLA2	NM_020376.4	c.1433A>G	p.Gln478Arg	missense_variant	Exon 10 of 10	ENST00000336615.9	NP_065109.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PNPLA2	ENST00000336615.9	c.1433A>G	p.Gln478Arg	missense_variant	Exon 10 of 10	1	NM_020376.4	ENSP00000337701.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.0000115 AC: 16 AN: 1386332 Hom.: 0 Cov.: 42 AF XY: 0.0000102 AC XY: 7 AN XY: 684700

African (AFR) AF: 0.00 AC: 0 AN: 31638

American (AMR) AF: 0.00 AC: 0 AN: 35962

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 24982

East Asian (EAS) AF: 0.00 AC: 0 AN: 35984

South Asian (SAS) AF: 0.00 AC: 0 AN: 79680

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 34164

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5690

European-Non Finnish (NFE) AF: 0.0000148 AC: 16 AN: 1080308

Other (OTH) AF: 0.00 AC: 0 AN: 57924

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neutral lipid storage myopathy Uncertain:1

Apr 09, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glutamine with arginine at codon 478 of the PNPLA2 protein (p.Gln478Arg). The glutamine residue is weakly conserved and there is a small physicochemical difference between glutamine and arginine. 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. 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 tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PNPLA2-related disease. While this variant is not present in population databases, the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.067
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.51
CADD	Benign	12
DANN	Benign	0.73
DEOGEN2	Benign	0.18	T
Eigen	Benign	-0.95
Eigen_PC	Benign	-0.94
FATHMM_MKL	Benign	0.21	N
LIST_S2	Benign	0.23	T
M_CAP	Benign	0.015	T
MetaRNN	Benign	0.13	T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.0	N
PhyloP100		1.7
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-0.78	N
REVEL	Benign	0.096
Sift	Pathogenic	0.0	D
Sift4G	Benign	0.32	T
Polyphen		0.047	B
Vest4		0.28
MutPred		0.057		Gain of glycosylation at P477 (P = 0.05);
MVP		0.19
MPC		0.24
ClinPred		0.21	T
GERP RS		1.6
Varity_R		0.10
gMVP		0.21
Mutation Taster		=97/3	polymorphism

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: rs929233099; hg19: chr11-824780;