NM_000492.4:c.3230T>C
Variant summary
Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PM1PM2PP2PP3_ModeratePP5_Very_Strong
The NM_000492.4(CFTR):c.3230T>C(p.Leu1077Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000031 in 1,613,514 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1077V) 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: Pathogenic. The variant received 15 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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CFTR | NM_000492.4 | c.3230T>C | p.Leu1077Pro | missense_variant | Exon 20 of 27 | ENST00000003084.11 | NP_000483.3 | |
CFTR-AS2 | NR_199597.1 | n.177+4558A>G | intron_variant | Intron 2 of 2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152108Hom.: 0 Cov.: 31 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251086 AF XY: 0.00000737 show subpopulations
GnomAD4 exome AF: 0.00000274 AC: 4AN: 1461406Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3AN XY: 727008 show subpopulations
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152108Hom.: 0 Cov.: 31 AF XY: 0.0000135 AC XY: 1AN XY: 74300 show subpopulations
ClinVar
Submissions by phenotype
Cystic fibrosis Pathogenic:10
The p.L1077P pathogenic mutation (also known as c.3230T>C), located in coding exon 20 of the CFTR gene, results from a T to C substitution at nucleotide position 3230. The leucine at codon 1077 is replaced by proline, an amino acid with similar properties. In one study, this mutation was identified in one individual with cystic fibrosis in conjunction with p.F508del (Bozon D et al. Hum. Mutat., 1994;3:330-2). In another study, this mutation was seen in 4 individuals with cystic fibrosis in conjunction with a second pathogenic mutation (Parisi GF et al. BMC Res Notes, 2013 Nov;6:461). This mutation is associated with elevated sweat chloride levels and pancreatic insufficiency; in vitro functional studies showed this mutation results in no to very little chloride conductance (Sosnay PR et al. Nat. Genet., 2013 Oct;45:1160-7). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -
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This variant was identified in 2 unrelated patients 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: PS3_SUP, PM2_SUP, PM3_VSTR, PP3, PP4 -
For these reasons, this variant has been classified as Pathogenic. This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 1077 of the CFTR protein (p.Leu1077Pro). This variant is present in population databases (rs139304906, gnomAD 0.0009%). This missense change has been observed in individual(s) with cystic fibrosis (PMID: 7517268, 17662673, 23974870, 24225052). ClinVar contains an entry for this variant (Variation ID: 53690). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt CFTR protein function. Experimental studies have shown that this missense change affects CFTR function (PMID: 23974870). -
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Disease-causing CFTR variant. See www.CFTR2.org for phenotype information. -
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. -
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Variant summary: The CFTR c.3230T>C (p.Leu1077Pro) variant involves the alteration of a conserved nucleotide. 5/5 in silico tools predict a damaging outcome for this variant. This variant was found in 1/120564 control chromosomes at a frequency of 0.0000083, which does not exceed the estimated maximal expected allele frequency of a pathogenic CFTR variant (0.0129603). The variant has been reported in numerous affected individuals in the literature and has been shown via in vitro functional studies to result in the complete loss of chloride transport/conduction (Van Goor_2013, Sosnay_2013). In addition, one clinical diagnostic laboratory/reputable database has classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -
CFTR-related disorder Pathogenic:2
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Cystic fibrosis;C0403814:Congenital bilateral aplasia of vas deferens from CFTR mutation Pathogenic:1
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not provided Pathogenic:1
PS3, PM3, PM2, PP3, PP5 -
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