Total submissions: 2
| Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
|---|---|---|---|---|---|---|---|---|
| Gene |
RCV000478601 | SCV000569099 | uncertain significance | not provided | 2016-01-05 | criteria provided, single submitter | clinical testing | A variant of uncertain significance has been identified in the CHRNA4 gene. The S426F variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. It was not observed in approximately 6,400 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The S426F variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size, and/or other properties. However, this substitution occurs at a position that is not conserved. Additionally, this amino acid substitution is not predicted to occur within the transmembrane region of the protein, where the vast majority of pathogenic missense variants have been identified in association with epilepsy (Steinlein et al., 2010). In silico analysis is inconsistent in its predictions as to whether or not the variant is damaging to the protein structure/function. Therefore, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant. |
| Invitae | RCV003766676 | SCV004683764 | uncertain significance | Autosomal dominant nocturnal frontal lobe epilepsy | 2023-03-26 | criteria provided, single submitter | clinical testing | This variant has not been reported in the literature in individuals affected with CHRNA4-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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt CHRNA4 protein function. ClinVar contains an entry for this variant (Variation ID: 420311). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 426 of the CHRNA4 protein (p.Ser426Phe). |