rs149353983
Variant summary
Our verdict is Uncertain significance. Variant got 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate
The NM_000492.4(CFTR):c.92G>A(p.Arg31His) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,612,454 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R31C) has been classified as Benign.
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 2 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.92G>A | p.Arg31His | missense_variant | Exon 2 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000132 AC: 2AN: 152056Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000558 AC: 14AN: 250924Hom.: 0 AF XY: 0.0000442 AC XY: 6AN XY: 135608
GnomAD4 exome AF: 0.0000260 AC: 38AN: 1460398Hom.: 0 Cov.: 29 AF XY: 0.0000275 AC XY: 20AN XY: 726678
GnomAD4 genome AF: 0.0000132 AC: 2AN: 152056Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74260
ClinVar
Submissions by phenotype
Cystic fibrosis Uncertain:5
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This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 31 of the CFTR protein (p.Arg31His). This variant is present in population databases (rs149353983, gnomAD 0.03%). This missense change has been observed in individual(s) with clinical features of cystic fibrosis (PMID: 25492507, 28040058). ClinVar contains an entry for this variant (Variation ID: 554829). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The histidine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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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The p.R31H variant (also known as c.92G>A), located in coding exon 2 of the CFTR gene, results from a G to A substitution at nucleotide position 92. The arginine at codon 31 is replaced by histidine, an amino acid with highly similar properties. This variant was identified in one individual with chronic pancreatitis and one individual with chronic bronchitis; a second CFTR variant was not identified in either individual (Nakano E et al. Dig. Dis. Sci., 2015 May;60:1297-307; El-Seedy A et al. Cell. Mol. Biol. (Noisy-le-grand), 2016 Nov;62:21-28). This amino acid position is not well conserved in available vertebrate species, and histidine is the reference amino acid in other vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on available evidence to date, the clinical significance of this alteration remains unclear. -
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CFTR-related disorder Uncertain:2
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not specified Uncertain:1
Variant summary: CFTR c.92G>A (p.Arg31His) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 5.6e-05 in 250924 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (5.6e-05 vs 0.013), allowing no conclusion about variant significance. c.92G>A has been reported in the literature in a compound heterozygous infant with a pathogenic allele and elevated Sweat Chloride levels (Sommerburg_2022) and as a non-informative genotype (missing second allele) in at-least two individuals, one with idiopathic chronic pancreatitis (example, Nakano_2015) and with an author assertion as "uncertain" in another with chronic bronchitis associated with hyperinflation detected in the plain chest X-ray (example, El-Seedy_2016). . These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 25492507, 28040058, 34996830, 34764021). Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all laboratories classified the variant as uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided Uncertain:1
The CFTR c.92G>A; p.Arg31His variant (rs149353983) is reported in the literature in individuals affected with chronic bronchitis or chronic pancreatitis, although a second variant was not detected (El-Seedy 2016, Nakano 2015). This variant is reported in ClinVar (Variation ID: 554829) and is found in the general population with an overall allele frequency of 0.006% (14/250924 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.193). Additionally, other variants at this codon (c.91C>T; p.Arg31Cys; c.92G>T p.Arg31Leu) have been reported in individuals with CFTR-related disorders (Bernardino 2000, Gomez-Lira 2001, McCague 2019, Munck 2020) although the clinical significance of these variants is uncertain. Due to limited information, the clinical significance of the p.Arg31His variant is uncertain at this time. References: Bernardino AL et al. Molecular analysis in Brazilian cystic fibrosis patients reveals five novel mutations. Genet Test. 2000;4(1):69-74. PMID: 10794365 El-Seedy A et al. Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene mutations in North Egyptian population: implications for the genetic diagnosis in Egypt. Cell Mol Biol (Noisy-le-grand). 2016 Nov 30;62(13):21-28. PMID: 28040058. Gomez-Lira M et al. CFTR and cationic trypsinogen mutations in idiopathic pancreatitis and neonatal hypertrypsinemia. Pancreatology. 2001;1(5):538-42. PMID: 12120234 McCague AF et al. Correlating Cystic Fibrosis Transmembrane Conductance Regulator Function with Clinical Features to Inform Precision Treatment of Cystic Fibrosis. Am J Respir Crit Care Med. 2019 May 1;199(9):1116-1126PMID: 30888834 Munck A et al. Phenotype of children with inconclusive cystic fibrosis diagnosis after newborn screening. Pediatr Pulmonol. 2020 Apr;55(4):918-928. PMID: 31916691. Nakano E et al. Targeted next-generation sequencing effectively analyzed the cystic fibrosis transmembrane conductance regulator gene in pancreatitis. Dig Dis Sci. 2015 May;60(5):1297-307. PMID: 25492507. -
Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Uncertain:1
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Congenital bilateral aplasia of vas deferens from CFTR mutation Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at