chr19-7542826-G-C

Position:

• chr19-7542826-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001166114.2(PNPLA6):​c.1428G>C​(p.Glu476Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PNPLA6 NM_001166114.2 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.02

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 Uncertain_significance. Variant got 1 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.12631392).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PNPLA6	NM_001166114.2	c.1428G>C	p.Glu476Asp	missense_variant	12/32	ENST00000600737.6	NP_001159586.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PNPLA6	ENST00000600737.6	c.1428G>C	p.Glu476Asp	missense_variant	12/32	1	NM_001166114.2	ENSP00000473211	P3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

May 12, 2017

- -

Hereditary spastic paraplegia 39 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 05, 2021

This sequence change replaces glutamic acid with aspartic acid at codon 437 of the PNPLA6 protein (p.Glu437Asp). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid and aspartic acid. This variant is not present in population databases (ExAC no frequency). This missense change has been observed in individual(s) with clinical features of hereditary spastic paraplegia (Invitae). ClinVar contains an entry for this variant (Variation ID: 448095). 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. 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	Benign	0.066
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	16
DANN	Uncertain	0.99
Eigen	Benign	-0.52
Eigen_PC	Benign	-0.43
FATHMM_MKL	Uncertain	0.83	D
LIST_S2	Benign	0.83	.;T;T;T;T
M_CAP	Benign	0.022	T
MetaRNN	Benign	0.13	T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationTaster	Benign	0.99	D;D;D;D
PrimateAI	Uncertain	0.67	T
PROVEAN	Benign	-1.2	N;N;N;N;.
REVEL	Benign	0.14
Sift	Benign	0.14	T;T;T;T;.
Sift4G	Benign	0.24	T;T;T;T;T
Polyphen		0.0020	B;.;.;B;.
Vest4		0.31
MutPred		0.21		.;.;.;.;Gain of relative solvent accessibility (P = 0.09);
MVP		0.32
MPC		0.16
ClinPred		0.13	T
GERP RS		3.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.073
gMVP		0.29

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: rs1555745911; hg19: chr19-7607712;