rs370510954
Variant summary
Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong
The NM_000136.3(FANCC):c.996+1G>T variant causes a splice donor, intron change. The variant allele was found at a frequency of 0.00000806 in 1,613,516 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).
Frequency
Consequence
NM_000136.3 splice_donor, intron
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 18 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
---|---|---|---|---|---|---|---|---|
FANCC | NM_000136.3 | c.996+1G>T | splice_donor_variant, intron_variant | Intron 10 of 14 | ENST00000289081.8 | NP_000127.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152208Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.00000795 AC: 2AN: 251450Hom.: 0 AF XY: 0.00 AC XY: 0AN XY: 135908
GnomAD4 exome AF: 0.00000753 AC: 11AN: 1461308Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4AN XY: 727034
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152208Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74352
ClinVar
Submissions by phenotype
Fanconi anemia complementation group C Pathogenic:5
Variant summary: FANCC c.996+1G>T is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing and loss of FANCC function. Several computational tools predict a significant impact on normal splicing: Three predict the variant abolishes a canonical 5' splicing donor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 8e-06 in 251450 control chromosomes. c.996+1G>T has been reported in the literature in at-least one presumed compound heterozygous individual affected with Fanconi Anemia (Pagliara_2023) and heterozygous individuals affected with Medulloblastoma, and Endometrial cancer (Gordhandas_2023,Waszak_2018). 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: 37865086, 36744932, 29753700). ClinVar contains an entry for this variant (Variation ID: 265137). Based on the evidence outlined above, the variant was classified as likely pathogenic. -
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NM_000136.2(FANCC):c.996+1G>T is a canonical splice variant classified as likely pathogenic in the context of Fanconi anemia, FANCC-related. c.996+1G>T has not been observed in cases with relevant disease. Functional assessments of this variant are not available in the literature. c.996+1G>T has been observed in population frequency databases (gnomAD: AMR 0.003%). In summary, NM_000136.2(FANCC):c.996+1G>T is a canonical splice variant in a gene where loss of function is a known mechanism of disease, is predicted to disrupt protein function, and has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
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not provided Pathogenic:2
FANCC: PVS1 -
Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); Observed in individuals with Hodgkin lymphoma, neuroblastoma, or breast and/or ovarian cancer (Waszak et al., 2018; Kim et al., 2021; Espinel et al., 2022); This variant is associated with the following publications: (PMID: 10094191, 36497448, 29753700, 29922827, 35626031, 34308104) -
Fanconi anemia Pathogenic:1
This sequence change affects a donor splice site in intron 10 of the FANCC gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in FANCC are known to be pathogenic (PMID: 17924555). This variant is present in population databases (rs370510954, gnomAD 0.003%). Disruption of this splice site has been observed in individual(s) with clinical features of FANCC-related conditions (PMID: 29753700, 34654685). ClinVar contains an entry for this variant (Variation ID: 265137). 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 currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Hereditary cancer-predisposing syndrome Pathogenic:1
The c.996+1G>T intronic variant results from a G to T substitution one nucleotide after coding exon 9 of the FANCC gene. This alteration has been reported in an individual diagnosed with medulloblastoma (Waszak SM et al. Lancet Oncol., 2018 06;19:785-798). This alteration was also identified in 1 of 2184 patients with a personal history of breast and/or ovarian cancer (Espinel W et al. Cancers (Basel), 2022 May;14:). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site; however, direct evidence is insufficient at this time (Ambry internal data). In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as likely pathogenic. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at