19-7534846-A-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BS1_Supporting

The ENST00000221249.10(PNPLA6):c.-99A>C variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00178 in 152,000 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0018 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: PNPLA6 ENST00000221249.10 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -2.13

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 Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.92).
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00178 (271/152000) while in subpopulation AFR AF= 0.00611 (253/41426). AF 95% confidence interval is 0.00549. There are 0 homozygotes in gnomad4. There are 135 alleles in male gnomad4 subpopulation. Median coverage is 32. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PNPLA6	NM_001166111.2	c.-99A>C		5_prime_UTR_variant	1/34
PNPLA6	NM_001166112.2	c.-99A>C		5_prime_UTR_variant	2/34
PNPLA6	NM_001166113.1	c.-175A>C		5_prime_UTR_variant	1/35
PNPLA6	NM_006702.5	c.-99A>C		5_prime_UTR_variant	2/35

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PNPLA6	ENST00000221249.10	c.-99A>C		5_prime_UTR_variant	2/35	1		A1
PNPLA6	ENST00000450331.7	c.-175A>C		5_prime_UTR_variant	1/35	1		A1
PNPLA6	ENST00000414982.7	c.-99A>C		5_prime_UTR_variant	1/34	2

Frequencies

GnomAD3 genomes AF: 0.00178 AC: 271 AN: 151882 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00613

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000918

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00144

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1926 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 1086

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00178 AC: 271 AN: 152000 Hom.: 0 Cov.: 32 AF XY: 0.00182 AC XY: 135 AN XY: 74292

Gnomad4 AFR AF: 0.00611

Gnomad4 AMR AF: 0.000917

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00142

Alfa AF: 0.00173 Hom.: 0

Bravo AF: 0.00196

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Hereditary spastic paraplegia 39 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.92
Cadd	Benign	0.26
Dann	Benign	0.59

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

Other links and lift over

dbSNP: rs192922627; hg19: chr19-7599732;