chr1-110603751-A-AC
Variant names:
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PVS1PM2
The NM_004974.4(KCNA2):c.1031dupG(p.Ser344ArgfsTer10) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).
Frequency
Genomes: not found (cov: 32)
Consequence
KCNA2
NM_004974.4 frameshift
NM_004974.4 frameshift
Scores
Not classified
Clinical Significance
Conservation
PhyloP100: 7.91
Genes affected
KCNA2 (HGNC:6220): (potassium voltage-gated channel subfamily A member 2) Potassium channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, members of which allow nerve cells to efficiently repolarize following an action potential. The coding region of this gene is intronless, and the gene is clustered with genes KCNA3 and KCNA10 on chromosome 1. [provided by RefSeq, Jul 2008]
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ACMG classification
Classification made for transcript
Verdict is Pathogenic. Variant got 10 ACMG points.
PVS1
Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 26 pathogenic variants in the truncated region.
PM2
Very rare variant in population databases, with high coverage;
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes
GnomAD3 genomes
Cov.:
32
GnomAD4 exome Cov.: 34
GnomAD4 exome
Cov.:
34
GnomAD4 genome
GnomAD4 genome
Cov.:
32
ClinVar
Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link
Submissions by phenotype
Developmental and epileptic encephalopathy, 32 Uncertain:1
| Uncertain significance, criteria provided, single submitter | clinical testing | Labcorp Genetics (formerly Invitae), Labcorp | Apr 09, 2023 | This variant has not been reported in the literature in individuals affected with KCNA2-related conditions. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. ClinVar contains an entry for this variant (Variation ID: 542663). This premature translational stop signal has been observed in at least one individual who was not affected with KCNA2-related conditions (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Ser344Argfs*10) in the KCNA2 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 156 amino acid(s) of the KCNA2 protein. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
Splicing
Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at