7-117535383-G-A
Variant summary
Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1PM2PP3
The NM_000492.4(CFTR):c.715G>A(p.Gly239Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000551 in 1,613,986 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 Uncertain significance (★★).
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 5 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.715G>A | p.Gly239Arg | missense_variant | Exon 6 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000526 AC: 8AN: 152124Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000756 AC: 19AN: 251404Hom.: 0 AF XY: 0.0000589 AC XY: 8AN XY: 135876
GnomAD4 exome AF: 0.0000554 AC: 81AN: 1461862Hom.: 0 Cov.: 32 AF XY: 0.0000523 AC XY: 38AN XY: 727236
GnomAD4 genome AF: 0.0000526 AC: 8AN: 152124Hom.: 0 Cov.: 32 AF XY: 0.0000538 AC XY: 4AN XY: 74296
ClinVar
Submissions by phenotype
Cystic fibrosis Uncertain:4Other:1
The p.G239R variant (also known as c.715G>A), located in coding exon 6 of the CFTR gene, results from a G to A substitution at nucleotide position 715. The glycine at codon 239 is replaced by arginine, an amino acid with dissimilar properties. This variant was detected in an 80-year-old individual with chronic bronchorrhea and sinusitis; a second CFTR variant was not identified (Bienvenu T et al. Hum. Hered.;45:53-4). This variant was also reported in an adult with cystic fibrosis without a second CFTR variant identified (Gilljam M et al. Chest, 2004 Oct;126:1215-24). This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear. -
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This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 239 of the CFTR protein (p.Gly239Arg). This variant is present in population databases (rs397508788, gnomAD 0.02%). This missense change has been observed in individual(s) with cystic fibrosis or bronchiestasis (PMID: 7534748, 10445602, 15486385, 29944384). ClinVar contains an entry for this variant (Variation ID: 54046). 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 CFTR protein function with a negative predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
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not provided Uncertain:3
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not specified Uncertain:2
The CFTR c.715G>A; p.Gly239Arg variant (rs397508788) has been reported in individuals affected with mild cystic fibrosis and pancreatic sufficiency (Bienvenu 1995, Gilljam 2004, SickKids CFTR database) and one individual with symptomatic diffuse bronchiectasis (Puechal 1999). This variant is reported in ClinVar (Variation ID: 54046), and is found in the general population with an overall allele frequency of 0.007% (21/282,796 alleles) in the Genome Aggregation Database. The glycine at codon 239 is weakly conserved, and computational algorithms (PolyPhen-2, SIFT) predict that this variant is tolerated. Due to limited information, the clinical significance of the p.Gly239Arg variant is uncertain at this time. References: SickKids CFTR database: http://www.genet.sickkids.on.ca/cftr/MutationDetailPage.external?sp=146 Bienvenu T et al. Identification of a novel missense mutation G239R in exon 6a of the CFTR gene. Hum Hered. 1995; 45(1):53-4. Gilljam M et al. Clinical manifestations of cystic fibrosis among patients with diagnosis in adulthood. Chest. 2004 Oct;126(4):1215-24. Puechal X et al. Increased frequency of cystic fibrosis deltaF508 mutation in bronchiectasis associated with rheumatoid arthritis. Eur Respir J. 1999 Jun;13(6):1281-7. -
Variant summary: CFTR c.715G>A (p.Gly239Arg) results in a non-conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 7.6e-05 in 251404 control chromosomes (gnomAD). This frequency is not higher than predicted for a pathogenic variant in CFTR causing Cystic Fibrosis (7.6e-05 vs 0.013), allowing no conclusion about variant significance c.715G>A has been reported in the literature in individuals affected with Cystic Fibrosis (e.g., Gilljam_2004, Desai_2018), bronchiectasis (e.g., Puechal_1999), and chronic bronchorrhea and sinusitis with a sweat chloride level of 60 mmol/l (Bienvenu_1995), however no second variant was reported in these individuals. These reports therefore do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect resulted in approximately 58% of normal chloride channel conductance relative to wild type (e.g., Bihler_2023 (bioRxiv preprint, no PMID)). The following publications have been ascertained in the context of this evaluation (PMID: 7534748, 29944384, 15486385, 10445602, 34996830). ClinVar contains an entry for this variant (Variation ID: 54046). Based on the evidence outlined above, the variant was classified as uncertain significance. -
CFTR-related disorder Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at