rs773045474

Positions:

• chr9-95249293-T-C
• chr9-95249293-T-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000136.3(FANCC):​c.-2A>G variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,461,742 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000026 (0 hom.)
• Consequence: FANCC NM_000136.3 5_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.574

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FANCC	NM_000136.3	c.-2A>G		5_prime_UTR_variant	2/15	ENST00000289081.8	NP_000127.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FANCC	ENST00000289081.8	c.-2A>G		5_prime_UTR_variant	2/15	1	NM_000136.3	ENSP00000289081.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000800 AC: 2 AN: 250080 Hom.: 0 AF XY: 0.0000148 AC XY: 2 AN XY: 135270

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000260 AC: 38 AN: 1461742 Hom.: 0 Cov.: 31 AF XY: 0.0000275 AC XY: 20 AN XY: 727178

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000306

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 18, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Apr 19, 2022	This variant occurs in a non-coding region of the FANCC gene. It does not change the encoded amino acid sequence of the FANCC protein. This variant is present in population databases (rs773045474, 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: 216858). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a 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. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 31, 2022

The c.-2A>G variant is located in the 5' untranslated region (5’ UTR) of the FANCC gene. This variant results from an A to G substitution 2 bases upstream from the first translated codon. This nucleotide position is not well conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.68
CADD	Benign	18
DANN	Benign	0.82

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.47		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.47		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs773045474; hg19: chr9-98011575;