NM_000492.4:c.-4G>C
Variant summary
Our verdict is Benign. Variant got -8 ACMG points: 2P and 10B. PM2BP4_ModerateBP6_Very_Strong
The NM_000492.4(CFTR):c.-4G>C variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000157 in 1,613,808 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 Likely benign (★★).
Frequency
Consequence
NM_000492.4 5_prime_UTR
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -8 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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CFTR | NM_000492.4 | c.-4G>C | 5_prime_UTR_variant | Exon 1 of 27 | ENST00000003084.11 | NP_000483.3 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000151 AC: 23AN: 152076Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000756 AC: 19AN: 251160Hom.: 0 AF XY: 0.0000663 AC XY: 9AN XY: 135758
GnomAD4 exome AF: 0.000157 AC: 230AN: 1461732Hom.: 0 Cov.: 31 AF XY: 0.000157 AC XY: 114AN XY: 727176
GnomAD4 genome AF: 0.000151 AC: 23AN: 152076Hom.: 0 Cov.: 32 AF XY: 0.000148 AC XY: 11AN XY: 74258
ClinVar
Submissions by phenotype
Cystic fibrosis Benign:4
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. -
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not provided Benign:3
CFTR: BP4 -
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not specified Benign:2
Variant summary: CFTR c.-4G>C is located in the untranslated mRNA region upstream of the initiation codon. The variant allele was found at a frequency of 7.6e-05 in 251160 control chromosomes. This frequency is not significantly higher than estimated for a pathogenic variant in CFTR causing Cystic Fibrosis (7.6e-05 vs 0.013), allowing no conclusion about variant significance. c.-4G>C has been reported in CF patients who had F508del on the other chromosome (e.g. Zielenski_1991, Hadd_2004). Sickkids database references the variant in strong association with R117H. The variant was reportedly identified in cis with T5, R117H and R117H-T5 complex alleles (Hadd_2004; Lucarelli_2012; Regan_2015). Internal data support this observation with the variant being identified with R117H or R117H and T5 variants in the vast majority of tested samples. c.-4G>C has been reported to co-occur with two other pathogenic variants in multiple samples (data from internal testing and ClinVar). Lastly, the variant of interest has been described as polymorphism in published reports (e.g. Miller_1996). 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: 1710599, 8659542, 15507674, 25739099, 26436105, 32483343). ClinVar contains an entry for this variant (Variation ID: 53157). Based on the evidence outlined above, the variant was classified as likely benign. -
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CFTR-related disorder Benign:1
This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at