rs387906360
Variant summary
Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong
The NM_000492.4(CFTR):c.1021_1022dupTC(p.Phe342HisfsTer28) variant causes a frameshift change. The variant allele was found at a frequency of 0.0000849 in 1,614,034 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Variant results in nonsense mediated mRNA decay.
Frequency
Consequence
NM_000492.4 frameshift
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: Pathogenic. The variant received 16 ACMG points.
Transcripts
RefSeq
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
|---|---|---|---|---|---|---|---|---|
| CFTR | NM_000492.4 | c.1021_1022dupTC | p.Phe342HisfsTer28 | frameshift_variant | Exon 8 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152212Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000279 AC: 7AN: 251226 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000924 AC: 135AN: 1461822Hom.: 0 Cov.: 31 AF XY: 0.0000825 AC XY: 60AN XY: 727202 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152212Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1AN XY: 74368 show subpopulations
ClinVar
Submissions by phenotype
Cystic fibrosis Pathogenic:11
Variant summary: CFTR c.1021_1022dupTC (p.Phe342HisfsX28) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.8e-05 in 251226 control chromosomes (gnomAD). c.1021_1022dupTC has been reported in the literature in numerous individuals affected with Cystic Fibrosis (e.g. Iannuzzi_1991, Friedman_1995, Pignatti_1995, Ahmed_2003, Sosnay_2013). These data indicate that the variant is very likely to be associated with disease. 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: 12865275, 7550243, 1990834, 7543317, 23974870). ClinVar contains an entry for this variant (Variation ID: 7134). Based on the evidence outlined above, the variant was classified as pathogenic. -
The c.1021_1022dupTC pathogenic mutation, located in coding exon 8 of the CFTR gene, results from a duplication of TC at nucleotide position 1021, causing a translational frameshift with a predicted alternate stop codon (p.F342Hfs*28). This variant was reported to account for 0.5% of 1,238 predominantly American Caucasian cystic fibrosis (CF) chromosomes (Friedman KJ et al. Hum. Mutat., 1995;6:95-6). In another study, this variant was reportedly detected in trans with p.F508del in two unrelated individuals with elevated sweat chloride levels, pancreatic insufficiency, and poor growth (Alper OM et al. Am. J. Med. Genet. A, 2003 Jul;120A:294-5). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Of note, this alteration is also known as c.1154_1155insTC, 1154insTC, and c.1022_1023insTC in published literature. In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -
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This sequence change creates a premature translational stop signal (p.Phe342Hisfs*28) in the CFTR gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in CFTR are known to be pathogenic (PMID: 1695717, 7691345, 9725922). This variant is present in population databases (rs751437088, gnomAD 0.006%). This premature translational stop signal has been observed in individuals with Cystic Fibrosis (CF) (PMID: 1990834, 12865275, 23974870; Invitae). This variant is also known as 1154insTC. ClinVar contains an entry for this variant (Variation ID: 7134). For these reasons, this variant has been classified as Pathogenic. -
Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -
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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. -
The CFTR c.1021_1022dupTC, p.Phe342fs variant (rs387906360, ClinVar Variation ID: 7134), also known as 1154insTC, has been reported in-trans with a pathogenic CFTR variant in multiple cystic fibrosis patients and is often associated with pancreatic insufficiency (Alper 2003, Friedman 1995, Iannuzzi 1991, Ooi 2012, Sosnay 2013, CFTR2 database). This variant is found in the non-Finnish European population with an allele frequency of 0.005% (7/128980 alleles) in the Genome Aggregation Database (v2.1.1). This variant causes a frameshift by inserting two nucleotides, so it is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, the variant is classified as pathogenic. References: CFTR2 database: http://cftr2.org/ Alper O et al. 1154insTC is not a rare CFTR mutation. Am J Med Genet A. 2003; 120A(2):294-5. PMID: 12833419 Friedman K et al. Relatively high prevalence of the CFTR mutations, G85E and 1154insTC. Hum Mutat. 1995; 6(1):95-6. PMID: 7550243 Iannuzzi M et al. Two frameshift mutations in the cystic fibrosis gene. Am J Hum Genet. 1991; 48(2):227-31. PMID: 1990834 Ooi C. et al. Cystic fibrosis transmembrane conductance regulator (CFTR) gene mutations in pancreatitis. J Cyst Fibros. 2012; 11(5):355-62. PMID: 22658665 Sosnay PR et al. Defining the disease liability of variants in the cystic fibrosis transmembrane conductance regulator gene. Nat Genet. 2013; 45(10):1160-7. PMID: 23974870 -
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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: PVS1, PM2_SUP, PM3_VSTR, PP4 -
not provided Pathogenic:4
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PP5, PM2, PVS1 -
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This frameshift variant causes the premature termination of CFTR protein synthesis. In addition, it has been reported in individuals affected with Cystic Fibrosis in the published literature (PMID: 7550243 (1995), 26708955 (2016), 23974870 (2013), 22658665 (2012), 1990834 (1991), 12865275 (2003)). Therefore, the variant is classified as pathogenic. -
CFTR-related disorder Pathogenic:3
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The CFTR c.1021_1022dupTC variant is predicted to result in a frameshift and premature protein termination (p.Phe342Hisfs*28). This variant has been reported to be causative for cystic fibrosis and cystic fibrosis with pancreatic insufficiency (reported as c.1154insTC, Iannuzzi et al., 1991. PubMed ID: 1990834; Table S2, Sosnay et al. 2013. PubMed ID: 23974870; Ooi and Durie. 2012. PubMed ID: 22658665). Frameshift variants in CFTR are expected to be pathogenic. This variant is interpreted as pathogenic. -
Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
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Cystic fibrosis;C0238339:Hereditary pancreatitis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation;C2749757:Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
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Bronchiectasis with or without elevated sweat chloride 1 Pathogenic:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at