rs977989588
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_004519.4(KCNQ3):c.2123G>T(p.Ser708Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,614,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_004519.4 missense
Scores
Clinical Significance
Conservation
Publications
- seizures, benign familial neonatal, 2Inheritance: AD Classification: STRONG, MODERATE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
- benign familial infantile epilepsyInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- benign neonatal seizuresInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
- genetic developmental and epileptic encephalopathyInheritance: AR Classification: LIMITED Submitted by: Ambry Genetics
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ACMG classification
Our verdict: Likely_benign. The variant received -3 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152178Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251376 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.0000103 AC: 15AN: 1461886Hom.: 0 Cov.: 32 AF XY: 0.0000110 AC XY: 8AN XY: 727246 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152178Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74354 show subpopulations ⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
ClinVar
Submissions by phenotype
not provided Uncertain:3
Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -
The KCNQ3 p.Ser588Ile variant was not identified in the literature nor was it identified in LOVD 3.0. The variant was identified in dbSNP (ID: rs977989588) and in ClinVar (classified as likely benign by Invitae and as uncertain significance by CeGaT (Germany)). The variant was identified in control databases in 2 of 282774 chromosomes at a frequency of 0.000007073 (Genome Aggregation Database March 6, 2019, v2.1.1). The variant was observed in the European (non-Finnish) population in 2 of 129126 chromosomes (freq: 0.000015), but was not observed in the African, Latino, Ashkenazi Jewish, East Asian, European (Finnish), Other, or South Asian populations. The p.Ser588 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and 3 of 4 in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information the clinical significance of this variant cannot be determined with certainty at this time. This variant is classified as a variant of uncertain significance. -
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Benign neonatal seizures Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at