Our verdict is Uncertain significance. Variant got 0 ACMG points: 1P and 1B. PP3BP6
The NM_001161352.2(KCNMA1):c.3147G>A(p.Ala1049=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000372 in 1,613,258 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 predicting alterations to normal splicing. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
KCNMA1 (HGNC:6284): (potassium calcium-activated channel subfamily M alpha 1) This gene encodes the alpha subunit of calcium-activated BK channel. The encoded protein is involved in several physiological processes including smooth muscle contraction, neurotransmitter release and neuronal excitability. Mutations in this gene are associated with a spectrum of neurological disorders including Paroxysmal Nonkinesigenic Dyskinesia 3, Idiopathic Generalized Epilepsy 16 and Liang-Wang syndrome. [provided by RefSeq, Aug 2022]
Verdict is Uncertain_significance. Variant got 0 ACMG points.
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.
BP6
Variant 10-76909966-C-T is Benign according to our data. Variant chr10-76909966-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 532941.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=2}.
Likely benign, criteria provided, single submitter
clinical testing
CeGaT Center for Human Genetics Tuebingen
Jun 01, 2023
KCNMA1: BP4 -
Uncertain significance, criteria provided, single submitter
clinical testing
GeneDx
Jun 15, 2021
Has not been previously published as pathogenic or benign to our knowledge; In-silico analysis, which includes splice predictors and evolutionary conservation, is inconclusive as to whether the variant alters gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 27535533) -
Uncertain significance, criteria provided, single submitter
clinical testing
Invitae
Nov 13, 2023
This sequence change affects codon 991 of the KCNMA1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the KCNMA1 protein. This variant also falls at the last nucleotide of exon 24, which is part of the consensus splice site for this exon. This variant is present in population databases (rs201397661, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with KCNMA1-related conditions. ClinVar contains an entry for this variant (Variation ID: 532941). 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 is not likely to affect RNA splicing. 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. -