18-10714931-C-T

Position:

• chr18-10714931-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001378183.1(PIEZO2):​c.5257-1G>A variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000722 in 1,384,636 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 7.2e-7 (0 hom.)
• Consequence: PIEZO2 NM_001378183.1 splice_acceptor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.43

Genes affected

PIEZO2 (HGNC:26270): (piezo type mechanosensitive ion channel component 2) The protein encoded by this gene contains more than thirty transmembrane domains and likely functions as part of mechanically-activated (MA) cation channels. These channels serve to connect mechanical forces to biological signals. The encoded protein quickly adapts MA currents in somatosensory neurons. Defects in this gene are a cause of type 5 distal arthrogryposis. Several alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known. [provided by RefSeq, Feb 2014]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 6.7, offset of 1, new splice context is: aatgtctcattctcctcaAGgca. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 18-10714931-C-T is Pathogenic according to our data. Variant chr18-10714931-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 489219.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PIEZO2	NM_001378183.1	c.5257-1G>A		splice_acceptor_variant		ENST00000674853.1	NP_001365112.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PIEZO2	ENST00000674853.1	c.5257-1G>A		splice_acceptor_variant			NM_001378183.1	ENSP00000501957

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 7.22e-7 AC: 1 AN: 1384636 Hom.: 0 Cov.: 31 AF XY: 0.00000146 AC XY: 1 AN XY: 683230

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: 9.27e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Dec 07, 2017

The c.5083-1G>A variant in the PIEZO2 gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This splice site variant destroys the canonical splice acceptor site in intron 35. It is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. The c.5083-1G>A variant is not observed in large population cohorts (Lek et al., 2016). We interpret c.5083-1G>A as a pathogenic variant. -

Arthrogryposis, distal, with impaired proprioception and touch Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Undiagnosed Diseases Network, NIH

Dec 11, 2017

This splice site mutation is categorized as deleterious according to ACMG guidelines (PMID: 18414213) and was found in trans with another variant (c.1528-1G>A) in a 6-year-old female with ataxia, hypotonia, mild dysmorphic features, delayed motor development, scoliosis. It is predicted to cause abnormal gene splicing, either leading to an abnormal message that is subject to nonsense-mediated mRNA decay, or to an abnormal protein product if the message is used for protein translation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	31
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.93
FATHMM_MKL	Pathogenic	0.99	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		6.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.77		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.24		Position offset: -2
DS_AL_spliceai		0.77		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555630216; hg19: chr18-10714929;