rs750559671
Variant summary
Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2
The NM_000492.4(CFTR):c.4297G>A(p.Glu1433Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000149 in 1,613,864 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. E1433D) has been classified as Uncertain significance.
Frequency
Consequence
NM_000492.4 missense
Scores
Clinical Significance
Conservation
Publications
- cystic fibrosisInheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, Orphanet
- congenital bilateral absence of vas deferensInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- hereditary chronic pancreatitisInheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Uncertain_significance. The variant received 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.4297G>A | p.Glu1433Lys | missense_variant | Exon 27 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152116Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000239 AC: 6AN: 250854 AF XY: 0.0000295 show subpopulations
GnomAD4 exome AF: 0.0000137 AC: 20AN: 1461748Hom.: 0 Cov.: 31 AF XY: 0.0000151 AC XY: 11AN XY: 727166 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152116Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74324 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Cystic fibrosis Uncertain:4
This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 1433 of the CFTR protein (p.Glu1433Lys). This variant is present in population databases (rs750559671, gnomAD 0.009%). This missense change has been observed in individual(s) with congenital absence of vas deferens and/or cystic fibrosis (PMID: 28546993, 32777524). ClinVar contains an entry for this variant (Variation ID: 558250). 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 tolerated. 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.E1433K variant (also known as c.4297G>A), located in coding exon 27 of the CFTR gene, results from a G to A substitution at nucleotide position 4297. The glutamic acid at codon 1433 is replaced by lysine, an amino acid with similar properties. This alteration was identified in an individual with a clinical diagnosis of cystic fibrosis however no specific clinical data was provided. A second CFTR alteration was not identified in this individual (Behar DM et al. Mol Genet Genomic Med, 2017 May;5:223-236). This alteration was also identified in an individual diagnosed with congenital absence of the vas deferens (CAVD) (Luo S et al. Gene, 2021 Jan;765:145045). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -
not specified Uncertain:1
Variant summary: CFTR c.4297G>A (p.Glu1433Lys) results in a conservative amino acid change located in the ABC transporter-like, ATP-binding domain (IPR003439) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2.4e-05 in 250854 control chromosomes. c.4297G>A has been reported in the literature as a non-informative genotype (second allele not specified) in at-least one individual each with Cystic Fibrosis/cohort of CBAVD/cohort of smokers with chronic bronchitis (example, Behar_2017, Luo_2021, Saferali_2022, Cheng_2022). These report(s) 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 (Gt channel conductance) 23% of normal chloride channel conductance relative to wild type (e.g., Bihler_2024). The following publications have been ascertained in the context of this evaluation (PMID: 28546993, 35119551, 32777524, 34996830, 38388235). ClinVar contains an entry for this variant (Variation ID: 558250). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -
CFTR-related disorder Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at