chr9-95171079-C-T
Variant summary
Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2PP3_Strong
The NM_000136.3(FANCC):c.521G>A(p.Arg174Gln) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,609,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).
Frequency
Consequence
NM_000136.3 missense, splice_region
Scores
Clinical Significance
Conservation
Genome browser will be placed here
ACMG classification
Verdict is Likely_pathogenic. Variant got 6 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
FANCC | NM_000136.3 | c.521G>A | p.Arg174Gln | missense_variant, splice_region_variant | Exon 6 of 15 | ENST00000289081.8 | NP_000127.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152042Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.0000159 AC: 4AN: 251118Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135746
GnomAD4 exome AF: 0.0000110 AC: 16AN: 1457566Hom.: 0 Cov.: 30 AF XY: 0.0000165 AC XY: 12AN XY: 725464
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152042Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2AN XY: 74262
ClinVar
Submissions by phenotype
Fanconi anemia Uncertain:2
This sequence change affects codon 174 of the FANCC mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the FANCC protein. This variant also falls at the last nucleotide of exon 6, which is part of the consensus splice site for this exon. This variant is present in population databases (rs755283850, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with FANCC-related conditions. ClinVar contains an entry for this variant (Variation ID: 409653). An algorithm developed to predict the effect of missense changes on protein structure and function outputs the following: PolyPhen-2: "Benign". The glutamine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. 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. -
- -
not provided Uncertain:1
Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports a deleterious effect on splicing; In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: Gordon2000[Book]) -
Fanconi anemia complementation group C Uncertain:1
- -
Hereditary cancer-predisposing syndrome Uncertain:1
The p.R174Q variant (also known as c.521G>A), located in coding exon 5 of the FANCC gene, results from a G to A substitution at nucleotide position 521. The amino acid change results in arginine to glutamine at codon 174, an amino acid with highly similar properties. However, this change occurs in the last base pair of coding exon 5, which makes it likely to have some effect on normal mRNA splicing. This nucleotide position is well conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. RNA studies have demonstrated that this alteration results in an incomplete splice defect; the clinical impact of this abnormal splicing is unknown at this time (Ambry internal data). This amino acid position is well conserved in available vertebrate species. In addition, as a missense substitution this is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at