rs148173473
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1PM2BP4
The NM_000492.4(CFTR):c.1606A>G(p.Lys536Glu) variant causes a missense change. The variant allele was found at a frequency of 0.0000174 in 1,610,426 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign 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 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.1606A>G | p.Lys536Glu | missense_variant | Exon 12 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000797 AC: 20AN: 250922Hom.: 0 AF XY: 0.0000664 AC XY: 9AN XY: 135616
GnomAD4 exome AF: 0.0000185 AC: 27AN: 1458232Hom.: 0 Cov.: 28 AF XY: 0.0000152 AC XY: 11AN XY: 725710
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152194Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74338
ClinVar
Submissions by phenotype
not provided Uncertain:5
The CFTR c.1606A>G; p.Lys536Glu variant (rs148173473) has been identified in newborn screening programs, and is reported in a newborn with a positive sweat chloride test with no second CFTR variant identified (Bozdogan 2021, Ibarra-Gonzalez 2018). This variant is also reported in ClinVar (Variation ID: 595238). It is observed in the Admixed American population with an allele frequency of 0.06% (21/35302 alleles) in the Genome Aggregation Database (v2.1.1). Computational analyses are uncertain whether this variant is neutral or deleterious (REVEL: 0.689). Due to limited information, the clinical significance of this variant is uncertain at this time. References: Bozdogan ST et al. Current Status of Genetic Diagnosis Laboratories and Frequency of Genetic Variants Associated with Cystic Fibrosis through a Newborn-Screening Program in Turkey. Genes (Basel). 2021 Jan 31;12(2):206. PMID: 33572515. Ibarra-Gonzalez I et al. Newborn cystic fibrosis screening in southeastern Mexico: Birth prevalence and novel CFTR gene variants. J Med Screen. 2018 Sep;25(3):119-125. PMID: 28992757. -
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The CFTR c.1606A>G (p.Lys536Glu) variant has been reported in the published literature in an individual with cystic fibrosis (PMID: 28992757 (2018)) and in a newborn screening study (PMID: 33572515 (2021)). The frequency of this variant in the general population, 0.00059 (21/35302 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant. -
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Cystic fibrosis Uncertain:3
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This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 536 of the CFTR protein (p.Lys536Glu). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with cystic fibrosis (PMID: 28992757). ClinVar contains an entry for this variant (Variation ID: 595238). 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. -
The p.K536E variant (also known as c.1606A>G), located in coding exon 12 of the CFTR gene, results from an A to G substitution at nucleotide position 1606. The lysine at codon 536 is replaced by glutamic acid, an amino acid with similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
CFTR-related disorder Uncertain:2
The CFTR c.1606A>G variant is predicted to result in the amino acid substitution p.Lys536Glu. This variant has been reported in an individual with a positive sweat test without an identified second mutation (Ibarra-González et al 2018. PubMed ID: 28992757) and in an individual identified through newborn screening (Bozdogan ST et al 2021. PubMed ID: 33572515). This variant is reported in 0.059% of alleles in individuals of Latino descent in gnomAD and is interpreted as uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/595238/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
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not specified Uncertain:1
Variant summary: CFTR c.1606A>G (p.Lys536Glu) results in a conservative amino acid change located in the ABC transporter-like, ATP-binding domain of the encoded protein sequence. Two of four in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 8e-05 in 250922 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (8e-05 vs 0.013), allowing no conclusion about variant significance. c.1606A>G has been reported in the literature a patient with a positive sweat test without a second mutation detected (example, Ibarra-Gonzalez_2017), and during a newborn screening program, without strong evidence for causality provided (example, Bozdogan_2021). These reports do not provide unequivocal conclusions about association of the variant with Cystic Fibrosis. 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: 33572515, 28992757, 25735457). ClinVar contains an entry for this variant (Variation ID: 595238). Based on the evidence outlined above, the variant was classified as uncertain significance. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at