Total submissions: 2
| Submitter | RCV | SCV | Clinical significance | Condition | Last evaluated | Review status | Method | Comment |
|---|---|---|---|---|---|---|---|---|
| Invitae | RCV000536733 | SCV000625729 | uncertain significance | Cystic fibrosis | 2017-05-06 | criteria provided, single submitter | clinical testing | In summary, this variant is a rare missense change with uncertain impact on protein function. While it is absent from the population and reported in an affected individual, the available evidence is currently insufficient to determine its role in disease. Therefore, it has been classified as a Variant of Uncertain Significance. This variant has been observed with a second pathogenic variant in an individual in the Cystic Fibrosis Mutation Database who was found to have elevated sweat chloride levels and a positive IRT test on newborn screening (http://www.genet.sickkids.on.ca/). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with proline at codon 594 of the CFTR protein (p.Leu594Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. |
| Ambry Genetics | RCV000536733 | SCV002710361 | pathogenic | Cystic fibrosis | 2017-01-20 | criteria provided, single submitter | clinical testing | The p.L594P pathogenic mutation (also known as c.1781T>C), located in coding exon 14 of the CFTR gene, results from a T to C substitution at nucleotide position 1781. The leucine at codon 594 is replaced by proline, an amino acid with similar properties. In our internal cohort, this mutation has been confirmed in trans with another CFTR mutation in a patient with elevated sweat chloride levels, lung disease, and pancreatic insufficiency. Based on our internal structural analysis, this proline is located in the first nucleotide binding domain (NBD1) of the protein, and it is structurally more destabilizing than known pathogenic variants within this domain. This variant was not reported in the ExAC database, with coverage at this position. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. |