2-218342149-G-C

Variant names:

• chr2-218342149-G-C
• rs757255934
• NM_015488.5:c.781+5G>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_015488.5(PNKD):​c.781+5G>C variant causes a splice region, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,459,476 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: PNKD NM_015488.5 splice_region, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.21
• Publications: 0 publications found

Genes affected

PNKD (HGNC:9153): (PNKD metallo-beta-lactamase domain containing) This gene is thought to play a role in the regulation of myofibrillogenesis. Mutations in this gene have been associated with the movement disorder paroxysmal non-kinesigenic dyskinesia. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2010]

CATIP-AS2 (HGNC:41079): (CATIP antisense RNA 2)

MIR6810 (HGNC:49987): (microRNA 6810) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PNKD	NM_015488.5	c.781+5G>C		splice_region_variant, intron_variant	Intron 7 of 9	ENST00000273077.9	NP_056303.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PNKD	ENST00000273077.9	c.781+5G>C		splice_region_variant, intron_variant	Intron 7 of 9	1	NM_015488.5	ENSP00000273077.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000121 AC: 3 AN: 248852 AF XY: 0.0000223

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

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: 0.00000274 AC: 4 AN: 1459476 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 726094

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 51522

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5742

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111584

Other (OTH) AF: 0.0000166 AC: 1 AN: 60354

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Paroxysmal nonkinesigenic dyskinesia Uncertain:1

Nov 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 7 of the PNKD gene. It does not directly change the encoded amino acid sequence of the PNKD protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs757255934, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with PNKD-related conditions. ClinVar contains an entry for this variant (Variation ID: 574579). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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
BayesDel_noAF	Benign	-0.20
CADD	Uncertain	25
DANN	Uncertain	0.98
PhyloP100		9.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.96
SpliceAI score (max)		0.59		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.59		Position offset: -5

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

Other links and lift over

dbSNP: rs757255934; hg19: chr2-219206872;