19-7542578-C-A

Variant names:

• chr19-7542578-C-A
• rs763561590
• NM_001166114.2:c.1270C>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001166114.2(PNPLA6):​c.1270C>A​(p.Arg424Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,392 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R424C) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: PNPLA6 NM_001166114.2 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.28
• Publications: 2 publications found

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]

PNPLA6 Gene-Disease associations (from GenCC):

• ataxia-hypogonadism-choroidal dystrophy syndrome

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Orphanet
• PNPLA6-related spastic paraplegia with or without ataxia

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• retinal dystrophy-ataxia-pituitary hormone abnormality-hypogonadism syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• hereditary spastic paraplegia 39

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• cerebellar ataxia-hypogonadism syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Laurence-Moon syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• trichomegaly-retina pigmentary degeneration-dwarfism syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the PNPLA6 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 29 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 4.3547 (above the threshold of 3.09). Trascript score misZ: 3.5139 (above the threshold of 3.09). GenCC associations: The gene is linked to retinal dystrophy-ataxia-pituitary hormone abnormality-hypogonadism syndrome, cerebellar ataxia-hypogonadism syndrome, PNPLA6-related spastic paraplegia with or without ataxia, ataxia-hypogonadism-choroidal dystrophy syndrome, trichomegaly-retina pigmentary degeneration-dwarfism syndrome, hereditary spastic paraplegia 39, Laurence-Moon syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3487728).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNPLA6	NM_001166114.2	c.1270C>A	p.Arg424Ser	missense_variant	Exon 11 of 32	ENST00000600737.6	NP_001159586.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PNPLA6	ENST00000600737.6	c.1270C>A	p.Arg424Ser	missense_variant	Exon 11 of 32	1	NM_001166114.2	ENSP00000473211.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249182 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461392 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 727002

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.0000224 AC: 1 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53044

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111904

Other (OTH) AF: 0.00 AC: 0 AN: 60390

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Uncertain	0.012	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.53	.;.;D;.;.
Eigen	Benign	-0.10
Eigen_PC	Benign	0.061
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Pathogenic	0.97	.;D;D;D;D
M_CAP	Benign	0.064	D
MetaRNN	Benign	0.35	T;T;T;T;T
MetaSVM	Benign	-0.97	T
PhyloP100		1.3
PrimateAI	Uncertain	0.65	T
PROVEAN	Benign	-1.8	N;N;N;N;.
REVEL	Benign	0.18
Sift	Benign	0.35	T;T;T;T;.
Sift4G	Benign	0.74	T;T;T;T;T
Polyphen		0.14	B;.;.;B;.
Vest4		0.70
MutPred		0.26		.;.;.;.;Loss of catalytic residue at R424 (P = 0.0286);
MVP		0.30
MPC		0.21
ClinPred		0.38	T
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.31
gMVP		0.70
Mutation Taster		=68/32	polymorphism

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

Other links and lift over

dbSNP: rs763561590; hg19: chr19-7607464;