rs138629441
Variant summary
Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_StrongBP6BS2
The NM_000136.3(FANCC):c.178G>A(p.Val60Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00151 in 1,612,712 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).
Frequency
Consequence
NM_000136.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Benign. Variant got -9 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | MANE | Protein | UniProt |
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FANCC | NM_000136.3 | c.178G>A | p.Val60Ile | missense_variant | Exon 3 of 15 | ENST00000289081.8 | NP_000127.2 |
Ensembl
Frequencies
GnomAD3 genomes AF: 0.000874 AC: 133AN: 152140Hom.: 0 Cov.: 32
GnomAD3 exomes AF: 0.000885 AC: 222AN: 250762Hom.: 0 AF XY: 0.000900 AC XY: 122AN XY: 135534
GnomAD4 exome AF: 0.00158 AC: 2309AN: 1460572Hom.: 2 Cov.: 30 AF XY: 0.00148 AC XY: 1075AN XY: 726714
GnomAD4 genome AF: 0.000874 AC: 133AN: 152140Hom.: 0 Cov.: 32 AF XY: 0.000646 AC XY: 48AN XY: 74314
ClinVar
Submissions by phenotype
Fanconi anemia complementation group C Uncertain:4Benign:3
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The FANCC c.178G>A (p.Val60Ile) missense change has a maximum subpopulation frequency of 0.19% in gnomAD v4.1.0 with 2 homozygotes (https://gnomad.broadinstitute.org/). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. This variant has been reported as heterozygous in two individuals with head and neck squamous cell carcinoma (PMID: 28678401). To our knowledge, this variant has not been reported in the literature in individuals with Fanconi anemia. In summary, this variant meets criteria to be classified as likely benign. -
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FANCC NM_000136.2 exon 3 p.Val60Ile (c.178G>A): This variant has not been reported in the literature in association with Fanconi anemia. This variant is present in 0.2% (108/68,020) of European alleles in the Genome Aggregation Database (https://gnomad.broadinstitute.org/variant/9-95247504-C-T?dataset=gnomad_r3). This variant is present in ClinVar, with classifications ranging from likely benign to Uncertain significance (Variation ID:127537). This variant amino acid Isoleucine (Ile) is present in more than 30 species including many mammals and is not well conserved among evolutionarily distant species; this suggests that this variant may not impact the protein. Additional computational prediction tools do not suggest an impact. Splice prediction tools suggest that this variant may affect splicing. However, further studies are needed to understand its impact. In summary, data on this variant is insufficient for disease classification. Therefore, the clinical significance of this variant is uncertain. -
This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -
This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
not provided Uncertain:2Benign:3
This variant is associated with the following publications: (PMID: 14695169, 23028338, 27621404, 24123366, 15695377) -
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Curator: Arleen D. Auerbach. Submitter to LOVD: Arleen D. Auerbach. -
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FANCC: BP1, BP4, BS1 -
not specified Uncertain:1Benign:1
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Variant summary: FANCC c.178G>A (p.Val60Ile) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00091 in 253266 control chromosomes. This frequency is lower than the estimated maximum frequency expected for a pathogenic variant in FANCC causing Fanconi Anemia Group C (0.00091 vs 0.0018), allowing no conclusion about variant significance. c.178G>A has been reported in the literature in individuals affected with breast, prostate, pancreatic, and head and neck squamous cell carcinoma, as well as in healthy controls (e.g. Seal_2003, Thompson_2012, Chandrasekharappa_2017, Couch_2005, Dudley_2018, Verhagen_2018, Hong_2018, Bonache_2018). These reports suggest that c.178G>A (legacy name 433G>A) is unlikely to be associated with these types of cancer, but do not provide unequivocal conclusions about association of the variant with Fanconi Anemia Group C. Co-occurrence with another pathogenic variant has been reported (BRCA2 c.5585_5588delTGAA, p.V1862fs*11; internal sample). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported, but multiple authors consider the variant as neutral polymorphism (Savoia_1996, Verhagen_2018). Nine other ClinVar submitters (evaluation after 2014) have cited the variant as likely benign (n=5) and uncertain significance (n=4). Based on the evidence outlined above, the variant was classified as likely benign. -
Fanconi anemia Benign:2
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FANCC-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). -
Malignant tumor of breast Benign:1
The FANCC p.Val60Ile variant was identified in 4 of 1924 proband chromosomes (frequency: 0.002) from individuals or families with breast or pancreatic cancer and was present in 7 of 2384 control chromosomes (frequency: 0.003) from healthy individuals (Seal 2003, Couch 2005, Thompson 2012). The variant was identified in dbSNP (rs138629441) as “with other allele,” ClinVar (classified as likely benign by GeneDx, Ambry Genetics and 2 other submitters; and uncertain significance by Invitae and 2 other submitters) and LOVD 3.0 (observed 1x). The variant was identified in control databases in 237 of 276,496 chromosomes at a frequency of 0.0009, increasing the likelihood this could be a low frequency benign variant (Genome Aggregation Database Feb 27, 2017). The variant was observed in the following populations: African in 6 of 23,998 chromosomes (freq: 0.0003), Other in 6 of 6456 chromosomes (freq: 0.001), Latino in 21 of 34,398 chromosomes (freq: 0.0006), European in 181 of 126208 chromosomes (freq: 0.001434), Ashkenazi Jewish in 3 of 10,132 chromosomes (freq: 0.0003), East Asian in 1 of 18,836 chromosomes (freq: 0.00005), Finnish in 4 of 25,692 chromosomes (freq: 0.0002), and South Asian in 15 of 30,776 chromosomes (freq: 0.0005). The p.Val60 residue is not conserved in mammals and computational analyses (PolyPhen-2, SIFT, AlignGVGD, BLOSUM, MutationTaster) do not suggest a high likelihood of impact to the protein; however, this information is not predictive enough to rule out pathogenicity. The variant occurs outside of the splicing consensus sequence and in silico or computational prediction software programs (SpliceSiteFinder, MaxEntScan, NNSPLICE, GeneSplicer) do not predict a difference in splicing. In summary, based on the above information, the clinical significance of this variant cannot be determined with certainty at this time although we would lean towards a more benign role for this variant. This variant is classified as likely benign. -
Hereditary cancer-predisposing syndrome Benign:1
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. -
Hereditary cancer Benign:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at