NM_004519.4:c.1564G>A
Variant summary
Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBP6
The NM_004519.4(KCNQ3):c.1564G>A(p.Val522Ile) variant causes a missense change. The variant allele was found at a frequency of 0.0000471 in 1,591,502 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V522D) has been classified as Uncertain significance.
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: 0.0000460 AC: 7AN: 152070Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000789 AC: 18AN: 228138 AF XY: 0.0000736 show subpopulations
GnomAD4 exome AF: 0.0000472 AC: 68AN: 1439314Hom.: 0 Cov.: 30 AF XY: 0.0000392 AC XY: 28AN XY: 713940 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000460 AC: 7AN: 152188Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74408 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
not provided Uncertain:2
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Benign neonatal seizures Uncertain:1Benign:1
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This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 522 of the KCNQ3 protein (p.Val522Ile). This variant is present in population databases (rs143683496, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with KCNQ3-related conditions. ClinVar contains an entry for this variant (Variation ID: 193878). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt KCNQ3 protein function with a negative predictive value of 80%. 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. -
Inborn genetic diseases Benign:1
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Seizures, benign familial neonatal, 2 Benign: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 and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at