NM_000492.4:c.2417A>G
Variant summary
Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5
The NM_000492.4(CFTR):āc.2417A>Gā(p.Asp806Gly) variant causes a missense change. The variant allele was found at a frequency of 0.0000131 in 1,377,414 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Likely_pathogenic. Variant got 7 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.2417A>G | p.Asp806Gly | missense_variant | Exon 14 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.0000111 AC: 2AN: 179966Hom.: 0 AF XY: 0.0000105 AC XY: 1AN XY: 94970
GnomAD4 exome AF: 0.0000131 AC: 18AN: 1377414Hom.: 0 Cov.: 31 AF XY: 0.0000177 AC XY: 12AN XY: 678654
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Cystic fibrosis Pathogenic:2Uncertain:2Other:1
- -
- -
The p.D806G variant (also known as c.2417A>G), located in coding exon 14 of the CFTR gene, results from an A to G substitution at nucleotide position 2417. The aspartic acid at codon 806 is replaced by glycine, an amino acid with similar properties. This alteration has been identified in multiple individuals diagnosed with cystic fibrosis that also carried p.F508del (Strom CM et al. Genet Med;5:9-14; Petrova NV et al. Clin Genet, 2019 03;95:444-447). This alteration was also reported in trans with the p.F508del mutation in a newborn with a negative sweat test (Narzi L et al. Clin. Genet., 2007 Jul;72:39-46). This alteration has also been identified in an individual diagnosed with pancreatic cancer (Tavano F et al. Mol Med, 2023 Jan;29:14). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
This sequence change replaces aspartic acid, which is acidic and polar, with glycine, which is neutral and non-polar, at codon 806 of the CFTR protein (p.Asp806Gly). This variant is present in population databases (rs397508375, gnomAD 0.005%). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 12544470, 30548586, 32429104). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 53487). 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 expected to disrupt CFTR protein function with a positive predictive value of 80%. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
- -
not provided Pathogenic:1Uncertain:2
- -
The CFTR c.2417A>G; p.Asp806Gly variant (rs397508375; ClinVar Variation ID: 53487) is reported in the literature in the compound heterozygous state with a second pathogenic variant in individuals affected with cystic fibrosis (Petrova 2019, Strom 2003). It has also been reported with F508del in a newborn with a normal sweat chloride (Narzi 2007). One functional study showed that the variant protein has ~50% of baseline function compared to wild type (Bihler 2024). This variant is only found on two alleles in the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.929). Due to limited information, the clinical significance of this variant is uncertain at this time. References: Bihler H et al. In vitro modulator responsiveness of 655 CFTR variants found in people with cystic fibrosis. J Cyst Fibros. 2024 Jul;23(4):664-675. PMID: 38388235. Narzi L et al. Does cystic fibrosis neonatal screening detect atypical CF forms? Extended genetic characterization and 4-year clinical follow-up. Clin Genet. 2007 Jul;72(1):39-46. Petrova NV et al. Comprehensive genotyping reveals novel CFTR variants in cystic fibrosis patients from the Russian Federation. Clin Genet. 2019 Mar;95(3):444-447. PMID: 30548586. Strom CM et al. Extensive sequencing of the cystic fibrosis transmembrane regulator gene: assay validation and unexpected benefits of developing a comprehensive test. Genet Med. 2003 Jan-Feb;5(1):9-14. -
Observed with other CFTR variants, phase (cis or trans) unknown, in individuals with sweat chloride levels or nasal potential difference (NPD) within normal range (Narzi 2007, Tridello 2016); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34426522, 30938940, 30548586, 17594398, 12544470, 32429104, 33572515, 25880441, 19897426, 25735457, 27423539, 34996830, 34405919, 36717774) -
CFTR-related disorder Pathogenic:1
- -
Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
- -
Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
- -
Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
- -
Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
- -
not specified Uncertain:1
Variant summary: CFTR c.2417A>G (p.Asp806Gly) results in a non-conservative amino acid change located in the CFTR regulator domain (IPR025837) of the encoded protein sequence. Four of four in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.1e-05 in 179966 control chromosomes. c.2417A>G has been reported in (assumed) compound heterozygous individuals affected with (suspected) cystic fibrosis (Strom_2003, Picci_2010), however, it was also observed in trans with a pathogenic variant (p.F508del) in a newborn with a negative sweat test (Narzi_2007). In addition, the variant was listed to be found in cohorts of CF patients and newborns with positive screening tests, however no second variant was specified in these cases (Atag_2019, Petrova_2020, Bozdogan_2021). These data do not allow clear conclusions about variant significance. At least one publication reports experimental evidence evaluating an impact on protein function, demonstrating that the variant resulted in approximately 50% of normal chloride channel conductance relative to wild type (Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 19897426, 12544470, 17594398, 25735457, 25880441, 30548586, 30938940, 33572515, 34405919, 36717774, 38388235). ClinVar contains an entry for this variant (Variation ID: 53487). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at