chr19-7556710-G-A

Position:

• chr19-7556710-G-A

Variant summary

Our verdict is Pathogenic. Variant got 13 ACMG points: 13P and 0B. PM2 PP2 PP3_Moderate PP5_Very_Strong

The NM_001166114.2(PNPLA6):​c.3266G>A​(p.Arg1089Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,461,128 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 Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: PNPLA6 NM_001166114.2 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 9.99

Genes affected

PNPLA6 (HGNC:16268): (patatin like phospholipase domain containing 6) This gene encodes a phospholipase that deacetylates intracellular phosphatidylcholine to produce glycerophosphocholine. It is thought to function in neurite outgrowth and process elongation during neuronal differentiation. The protein is anchored to the cytoplasmic face of the endoplasmic reticulum in both neurons and non-neuronal cells. Mutations in this gene result in autosomal recessive spastic paraplegia, and the protein is the target for neurodegeneration induced by organophosphorus compounds and chemical warfare agents. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 13 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PNPLA6. . Gene score misZ 4.3547 (greater than the threshold 3.09). Trascript score misZ 3.5139 (greater than threshold 3.09). GenCC has associacion of gene with trichomegaly-retina pigmentary degeneration-dwarfism syndrome, ataxia-hypogonadism-choroidal dystrophy syndrome, Laurence-Moon syndrome, cerebellar ataxia-hypogonadism syndrome, retinal dystrophy-ataxia-pituitary hormone abnormality-hypogonadism syndrome, PNPLA6-related spastic paraplegia with or without ataxia, hereditary spastic paraplegia 39.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.864
• PP5: Variant 19-7556710-G-A is Pathogenic according to our data. Variant chr19-7556710-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 183693.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr19-7556710-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PNPLA6	NM_001166114.2	c.3266G>A	p.Arg1089Gln	missense_variant	26/32	ENST00000600737.6	NP_001159586.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PNPLA6	ENST00000600737.6	c.3266G>A	p.Arg1089Gln	missense_variant	26/32	1	NM_001166114.2	ENSP00000473211	P3

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000411 AC: 6 AN: 1461128 Hom.: 0 Cov.: 32 AF XY: 0.00000413 AC XY: 3 AN XY: 726948

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000360

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

Alfa AF: 0.0000312 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Trichomegaly-retina pigmentary degeneration-dwarfism syndrome Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

Feb 01, 2015

- -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Nov 01, 2019

- -

Hereditary spastic paraplegia 39 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 29, 2022

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects PNPLA6 function (PMID: 25480986, 31780887). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt PNPLA6 protein function. ClinVar contains an entry for this variant (Variation ID: 183693). This variant is also known as p.Arg1099Gln. This missense change has been observed in individual(s) with Oliver-McFarlane syndrome (PMID: 25480986). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 1051 of the PNPLA6 protein (p.Arg1051Gln). -

Ataxia-hypogonadism-choroidal dystrophy syndrome Other:1

not provided, no classification provided

literature only

GeneReviews

-

To date reported only in compound heterozygotes with Oliver-McFarlane syndrome -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.64	.;.;D;.;.;.
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Pathogenic	0.99	.;D;D;D;D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Pathogenic	0.86	D;D;D;D;D;D
MetaSVM	Uncertain	0.19	D
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-3.8	D;D;D;D;.;.
REVEL	Uncertain	0.64
Sift	Uncertain	0.0020	D;D;D;D;.;.
Sift4G	Uncertain	0.0040	D;D;D;D;D;.
Polyphen		1.0	D;.;.;D;.;.
Vest4		0.62
MVP		0.78
MPC		2.2
ClinPred		1.0	D
GERP RS		5.0
Varity_R		0.70
gMVP		0.78

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: rs786201037; hg19: chr19-7621596;