NM_000136.3:c.1555dupA

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_000136.3(FANCC):c.1555dupA(p.Thr519AsnfsTer9) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,938 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

FANCC
NM_000136.3 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: -0.616

Variant links:

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]

FANCC links:

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]

AOPEP links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 14 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 9-95101828-G-GT is Pathogenic according to our data. Variant chr9-95101828-G-GT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 12048.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FANCC	NM_000136.3 link	c.1555dupA	p.Thr519AsnfsTer9	frameshift_variant	Exon 15 of 15	ENST00000289081.8	NP_000127.2	Q00597A0A024R9N2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FANCC	ENST00000289081.8 link	c.1555dupA	p.Thr519AsnfsTer9	frameshift_variant	Exon 15 of 15	1	NM_000136.3	ENSP00000289081.3		Q00597

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152248

Hom.:

Cov.:

show subpopulations

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461690

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727136

show subpopulations

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:

0.00000450

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152248

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74372

show subpopulations

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000712

Hom.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Fanconi anemia complementation group C

Pathogenic:2

Jul 29, 2021

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: FANCC c.1555dupA (p.Thr519AsnfsX9) 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 (e.g. p.Arg548X). The variant was absent in 251020 control chromosomes (gnomAD). c.1555dupA (also described in the literature as 1806insA) has been reported in compound heterozygosity with another pathogenic variant in one individual (Lo Ten Foe_1996). This individual was reported with normal complete blood cell count and observed phenotypic reversion to MMC resistance which was determined to be due to a detected mitotic crossover event between the mutated sites deduced to have occurred in the patient's hematopoietic system which lead to the production of a wild-type allele and an allele having the two mutations in cis (Lo Ten Foe_1997). Nevertheless, Lo Ten Foe et al (1996) using a functional assay demonstrated that the specific variant was not capable of restoring MMC hypersensitivity. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Jan 01, 1996

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Fanconi anemia

Pathogenic:1

Feb 01, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Thr519Asnfs*9) in the FANCC gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 40 amino acid(s) of the FANCC protein. This variant is present in population databases (rs794726667, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with clinical features of Fanconi anemia (PMID: 8829660). This variant is also known as 1806insA. ClinVar contains an entry for this variant (Variation ID: 12048). Algorithms developed to predict the effect of variants on protein structure and function are not available or were not evaluated for this variant. Experimental studies have shown that this premature translational stop signal affects FANCC function (PMID: 8882868). This variant disrupts a region of the FANCC protein in which other variant(s) (p.Arg548*) have been determined to be pathogenic (PMID: 8103176, 8882868, 24584348). 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

Mar 10, 2025

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Identified with a pathogenic FANCC variant, phase (cis or trans) unknown, in a patient with Fanconi anemia (PMID: 8829660); Frameshift variant predicted to result in abnormal protein length as the last 40 amino acids are replaced with 8 different amino acids, and other similar variants have been reported in HGMD; Published functional studies demonstrate an inability to correct MMC hypersensitivity suggesting loss of function (PMID: 8882868); Not observed at significant frequency in large population cohorts (gnomAD); Also known as 1806insA; This variant is associated with the following publications: (PMID: 8882868, 8829660) -

Hereditary cancer-predisposing syndrome

Pathogenic:1

Mar 19, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1555dupA variant, located in coding exon 14 of the FANCC gene, results from a duplication of A at nucleotide position 1555, causing a translational frameshift with a predicted alternate stop codon (p.T519Nfs*9). This alteration occurs at the 3' terminus of FANCC gene, is not expected to trigger nonsense-mediated mRNA decay, and only impacts the last 7% of the protein. However, premature stop codons are typically deleterious in nature and a significant portion of the protein is affected (Ambry internal data). Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.13

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over