19-49861609-C-G
Variant summary
Our verdict is Uncertain significance. The variant received 0 ACMG points: 1P and 1B. PP5BP4
The NM_007254.4(PNKP):c.1385G>C(p.Arg462Pro) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000404 in 1,558,160 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R462Q) has been classified as Likely benign.
Frequency
Consequence
NM_007254.4 missense, splice_region
Scores
Clinical Significance
Conservation
Publications
- ataxia - oculomotor apraxia type 4Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, G2P, Laboratory for Molecular Medicine
- microcephaly, seizures, and developmental delayInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae)
- Charcot-Marie-Tooth disease type 2B2Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
- genetic developmental and epileptic encephalopathyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Uncertain_significance. The variant received 0 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000395 AC: 6AN: 151974Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.000149 AC: 24AN: 161108 AF XY: 0.000126 show subpopulations
GnomAD4 exome AF: 0.0000405 AC: 57AN: 1406186Hom.: 0 Cov.: 38 AF XY: 0.0000374 AC XY: 26AN XY: 694576 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000395 AC: 6AN: 151974Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74234 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Pathogenic:1Uncertain:1
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Observed in a patient with ataxia and oculomotor apraxia type 4 who also harbored a second PNKP variant in trans (PMID: 27066586); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 31436889, 29891053, 22508754, 27232581, 27066586, 30956058, 39509559) -
Microcephaly, seizures, and developmental delay Uncertain:1Other:1
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. -
Variant interpretted as Likely pathogenic and reported on 04-19-2017 by Lab or GTR ID 61756. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
Inborn genetic diseases Pathogenic:1
The c.1385G>C (p.R462P) alteration is located in exon 15 (coding exon 14) of the PNKP gene. This alteration results from a G to C substitution at nucleotide position 1385, causing the arginine (R) at amino acid position 462 to be replaced by a proline (P). Based on data from gnomAD, the C allele has an overall frequency of 0.013% (25/192352) total alleles studied. The highest observed frequency was 0.229% (20/8732) of Ashkenazi Jewish alleles. This variant has been identified in the homozygous state and/or in conjunction with other PNKP variant(s) in individual(s) with features consistent with PNKP-related neurological disorder; in at least one instance, the variants were identified in trans (Paucar, 2016; Nair, 2016; Ambry internal data). This amino acid position is highly conserved in available vertebrate species. The in silico prediction for this alteration is inconclusive. Based on the available evidence, this alteration is classified as likely pathogenic. -
Developmental and epileptic encephalopathy, 12 Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 462 of the PNKP protein (p.Arg462Pro). This variant is present in population databases (rs376854895, gnomAD 0.2%). This missense change has been observed in individuals with PNKP-related conditions (PMID: 27066586, 27232581; internal data). ClinVar contains an entry for this variant (Variation ID: 206414). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at