rs730881709

Positions:

• chr9-95111489-C-CA

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000136.3(FANCC):​c.1302_1303insT​(p.Gly435TrpfsTer83) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,728 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. D434D) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: FANCC NM_000136.3 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: -0.900

Genes affected

FANCC (HGNC:3584): (FA complementation group C) The Fanconi anemia complementation group (FANC) currently includes FANCA, FANCB, FANCC, FANCD1 (also called BRCA2), FANCD2, FANCE, FANCF, FANCG, FANCI, FANCJ (also called BRIP1), FANCL, FANCM and FANCN (also called PALB2). The previously defined group FANCH is the same as FANCA. Fanconi anemia is a genetically heterogeneous recessive disorder characterized by cytogenetic instability, hypersensitivity to DNA crosslinking agents, increased chromosomal breakage, and defective DNA repair. The members of the Fanconi anemia complementation group do not share sequence similarity; they are related by their assembly into a common nuclear protein complex. This gene encodes the protein for complementation group C. [provided by RefSeq, Jul 2008]

AOPEP (HGNC:1361): (aminopeptidase O (putative)) This gene encodes a member of the M1 zinc aminopeptidase family. The encoded protein is a zinc-dependent metallopeptidase that catalyzes the removal of an amino acid from the amino terminus of a protein or peptide. This protein may play a role in the generation of angiotensin IV. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Oct 2010]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-95111489-C-CA is Pathogenic according to our data. Variant chr9-95111489-C-CA is described in ClinVar as [Likely_pathogenic]. Clinvar id is 182467.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FANCC	NM_000136.3	c.1302_1303insT	p.Gly435TrpfsTer83	frameshift_variant	13/15	ENST00000289081.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FANCC	ENST00000289081.8	c.1302_1303insT	p.Gly435TrpfsTer83	frameshift_variant	13/15	1	NM_000136.3	P1

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152176 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250858 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135608

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000267 AC: 39 AN: 1461552 Hom.: 0 Cov.: 37 AF XY: 0.0000206 AC XY: 15 AN XY: 727062

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000342

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152176 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74342

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000227

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia complementation group C Pathogenic:3

Likely pathogenic, no assertion criteria provided	clinical testing	Counsyl	Apr 24, 2015	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 07, 2022	Variant summary: FANCC c.1302dupT (p.Gly435TrpfsX83) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-06 in 250858 control chromosomes. c.1302dupT has been reported in the literature in at-least one individual referred for cancer panel testing (Susswein_2016). This report does not provide unequivocal conclusions about association of the variant with Fanconi Anemia Group C. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 19, 2023	- -

Fanconi anemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Oct 24, 2023

This sequence change creates a premature translational stop signal (p.Gly435Trpfs*83) in the FANCC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 124 amino acid(s) of the FANCC protein. This variant is present in population databases (rs730881709, gnomAD 0.002%). 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: 182467). This variant disrupts a region of the FANCC protein in which other variant(s) (p.Arg548* and p.Leu554*) have been determined to be pathogenic (PMID: 8103176, 8613549, 8829660, 8882868). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 31, 2014

This duplication of one nucleotide is denoted FANCC c.1302dupT at the cDNA level and p.Gly435TrpfsX83 (G435WfsX83) at the protein level. The normal sequence, with the bases that are duplicated in brackets, is GTGA[T]GGGA. The duplication causes a frameshift, which changes a Glycine to a Tryptophan at codon 435, and creates a premature stop codon at position 83 of the new reading frame. Although this variant has not, to our knowledge, been reported in the literature, it is predicted to cause loss of normal protein function through protein truncation. we consider this variant to be pathogenic. FANCC has been only recently described in association with cancer predisposition and the risks are not well understood. Based on available data, the presence of a FANCC mutation may confer an increased risk for female breast cancer (Thompson 2012, Berwick 2007). Berwick et al. (2007) identified 33 female FANCC mutation carriers; all grandmothers of known Fanconi Anemia patients. In this group of women the observed cases of breast cancer (n=6) was significantly higher than the expected cases of breast cancer (SIR = 2.4). Thompson et al. (2012) studied 438 BRCA-negative breast cancer families and identified 3 families with deleterious FANCC mutations. In two of these families, the identified truncating FANCC mutations were found in multiple affected family members. The authors conclude that the co-segregation of FANCC mutations in these families appears to be consistent with moderately penetrant breast cancer alleles. Fanconi Anemia (FA) is a rare autosomal recessive condition that can be caused by two mutations (one affecting each allele) in the FANCC gene. This condition is characterized by an increased risk for childhood malignancy including leukemia and solid tumors, as well as distinctive physical abnormalities and bone marrow failure. If a FANCC mutation carrier'spartner is also a carrier for a FANCC mutation, the risk to have a child with FA is 25% with each pregnancy. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 27, 2023

The c.1302dupT pathogenic mutation, located in coding exon 12 of the FANCC gene, results from a duplication of T at nucleotide position 1302, causing a translational frameshift with a predicted alternate stop codon (p.G435Wfs*83). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs730881709; hg19: chr9-97873771;