rs121908790
Variant summary
Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2
The NM_000492.4(CFTR):c.164+12T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00024 in 1,260,782 control chromosomes in the GnomAD database, including 5 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Genomes: 𝑓 0.00011 ( 0 hom., cov: 32)
Exomes 𝑓: 0.00026 ( 5 hom. )
Consequence
CFTR
NM_000492.4 intron
NM_000492.4 intron
Scores
2
Clinical Significance
Conservation
PhyloP100: -0.181
Genes affected
CFTR (HGNC:1884): (CF transmembrane conductance regulator) This gene encodes a member of the ATP-binding cassette (ABC) transporter superfamily. The encoded protein functions as a chloride channel, making it unique among members of this protein family, and controls ion and water secretion and absorption in epithelial tissues. Channel activation is mediated by cycles of regulatory domain phosphorylation, ATP-binding by the nucleotide-binding domains, and ATP hydrolysis. Mutations in this gene cause cystic fibrosis, the most common lethal genetic disorder in populations of Northern European descent. The most frequently occurring mutation in cystic fibrosis, DeltaF508, results in impaired folding and trafficking of the encoded protein. Multiple pseudogenes have been identified in the human genome. [provided by RefSeq, Aug 2017]
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ACMG classification
Classification made for transcript
Verdict is Benign. Variant got -9 ACMG points.
BP4
?
Computational evidence support a benign effect (BayesDel_noAF=-0.89).
BP6
?
Variant 7-117504375-T-C is Benign according to our data. Variant chr7-117504375-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 53302.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=5, Likely_benign=3, not_provided=1, Benign=1}.
BS2
?
High Homozygotes in GnomAdExome at 2 AR gene
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
CFTR | NM_000492.4 | c.164+12T>C | intron_variant | ENST00000003084.11 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
CFTR | ENST00000003084.11 | c.164+12T>C | intron_variant | 1 | NM_000492.4 | P2 |
Frequencies
GnomAD3 genomes ? AF: 0.000112 AC: 17AN: 152222Hom.: 0 Cov.: 32
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GnomAD3 exomes AF: 0.000343 AC: 85AN: 247964Hom.: 2 AF XY: 0.000485 AC XY: 65AN XY: 134022
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ClinVar
Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:5Other:1
Revision: criteria provided, conflicting classifications
LINK: link
Submissions by phenotype
Cystic fibrosis Uncertain:3Benign:3Other:1
Uncertain significance, criteria provided, single submitter | clinical testing | Genome-Nilou Lab | Jul 22, 2021 | - - |
not provided, no classification provided | literature only | ClinVar Staff, National Center for Biotechnology Information (NCBI) | - | - - |
Benign, criteria provided, single submitter | clinical testing | Invitae | Jan 25, 2024 | - - |
Uncertain significance, criteria provided, single submitter | curation | Institute of Human Genetics, University of Leipzig Medical Center | Sep 05, 2022 | This variant was identified in 1 patient with a clinically confirmed diagnosis of cystic fibrosis. The variant was classified in the context of a project re-classifying variants in the German Cystic Fibrosis Registry (Muko.e.V.). Link: https://www.muko.info/angebote/qualitaetsmanagement/register/cf-einrichtungen/mukoweb. Criteria applied: PM3, PP4, BS2, BP2, BP4 - |
Uncertain significance, criteria provided, single submitter | clinical testing | Illumina Laboratory Services, Illumina | Nov 21, 2017 | The CFTR c.164+12T>C variant, which is often referred to as c.296+12T>C, has been reported in at least three studies and is found in a homozygous state in four individuals, three of whom were diagnosed with cystic fibrosis (CF) (Malone et al. 1998; Trujillano et al. 2015; Banjar et al. 2017). In a 6-year-old girl of Saudi descent, the c.164+12T>C variant was identified with a frameshift variant in a double homozygous state. The girl was reported to exhibit an earlier age of onset and lower BMI compared with other affected individuals (Banjar et al. 2017). The variant was shown to segregate with the disease in two families. The c.164+12T>C variant was absent from controls but is reported in a homozygous state in Exome Aggregation Consortium and Genome Aggregation Database. This variant is reported at a frequency of 0.019417 in the Gujarati Indian in Houston, Texas population of the 1000 Genomes Project, which is high but could be consistent with disease under-diagnosis in non-Caucasian populations. The evidence for this variant is limited. The c.164+12T>C variant is classified as unknown significance but suspicious for pathogenicity for CFTR-related disorders. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. - |
Likely benign, no assertion criteria provided | clinical testing | Natera, Inc. | Jan 03, 2020 | - - |
Likely benign, criteria provided, single submitter | clinical testing | Ambry Genetics | Jun 28, 2023 | This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. - |
not provided Uncertain:1Benign:1
Uncertain significance, criteria provided, single submitter | clinical testing | Eurofins Ntd Llc (ga) | Apr 10, 2017 | - - |
Likely benign, criteria provided, single submitter | clinical testing | ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories | Feb 24, 2023 | - - |
CFTR-related condition Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | PreventionGenetics, part of Exact Sciences | Feb 22, 2024 | The CFTR c.164+12T>C variant is predicted to interfere with splicing. This variant has been previously reported in homozygous state in individuals with cystic fibrosis (see for example: Trujillano et al. 2015. PubMed ID: 26436105 and Banjar et al. 2017. PubMed ID: 30805499). In one individual this variant was described as double homozygous, along with a second homozygous CFTR pathogenic variant (Banjar et al. 2017. PubMed ID: 30805499; ClinVarID:53841). This variant is reported in 0.26% of alleles in individuals of South Asian descent in gnomAD. At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. - |
not specified Benign:1
Likely benign, criteria provided, single submitter | clinical testing | Women's Health and Genetics/Laboratory Corporation of America, LabCorp | Jul 13, 2022 | Variant summary: CFTR c.164+12T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 4/4 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.00034 in 247964 control chromosomes, predominantly at a frequency of 0.0026 within the South Asian subpopulation in the gnomAD database, including 2 homozygotes. This frequency is not higher than expected for a pathogenic variant in CFTR causing Cystic Fibrosis (0.0026 vs 0.013), allowing no conclusion about variant significance. c.164+12T>C was reported in the homozygous state in two unrelated Cystic Fibrosis patients of Pakistani origin born to consanguineous parents (Malone_1998). However, due to the use of older mutational scanning technologies in this study, the possibility of missed co-occurrences with pathogenic variants in these patients cannot be ruled out. A more recent study reported the variant in one patient of Saudi Arabian descent with classic CF in homozygous state. However, the patient was also homozygous for another pathogenic CFTR variant (c.3889dupT, p.Ser1297PhefsX5) present in cis with the variant of interest (Banjar_2017), providing supporting evidence for a benign role. Another recent study (Lascano-Vaca_2020), reported the variant in heterozygous state in 2 pediatric CF patients from Ecuador with a detailed genotype provided for one of the patients who also had known pathogenic variants F508del and W1098X, providing further supporting evidence for a benign role. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two ClinVar submitters (evaluation after 2014) cite the variant as benign/likely benign and three ClinVar submitters (evaluation after 2014) cite it as uncertain significance. Based on the evidence outlined above, the variant was classified as likely benign. - |
Computational scores
Source:
Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
Cadd
Benign
Dann
Benign
Splicing
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SpliceAI score (max)
Details are displayed if max score is > 0.2
Find out detailed SpliceAI scores and Pangolin per-transcript scores at