rs759877008

Positions:

• chr16-89805275-C-A
• chr16-89805275-C-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM2 PP3_Strong PP5_Very_Strong

The NM_000135.4(FANCA):​c.709+5G>T variant causes a splice donor 5th base, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: FANCA NM_000135.4 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 3.45

Genes affected

FANCA (HGNC:3582): (FA complementation group A) 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 A. Alternative splicing results in multiple transcript variants encoding different isoforms. Mutations in this gene are the most common cause of Fanconi anemia. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 16-89805275-C-A is Pathogenic according to our data. Variant chr16-89805275-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 237056.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-89805275-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FANCA	NM_000135.4	c.709+5G>T		splice_donor_5th_base_variant, intron_variant		ENST00000389301.8
FANCA	NM_001018112.3	c.709+5G>T		splice_donor_5th_base_variant, intron_variant
FANCA	NM_001286167.3	c.709+5G>T		splice_donor_5th_base_variant, intron_variant
FANCA	NM_001351830.2	c.613+5G>T		splice_donor_5th_base_variant, intron_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FANCA	ENST00000389301.8	c.709+5G>T		splice_donor_5th_base_variant, intron_variant		1	NM_000135.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia complementation group A Pathogenic:2

Pathogenic, no assertion criteria provided	curation	Leiden Open Variation Database	Feb 28, 2020	Curator: Arleen D. Auerbach. Submitter to LOVD: Arleen D. Auerbach. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Jul 20, 2022	- -

Fanconi anemia Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 07, 2022

This variant disrupts the c.709+5G nucleotide in the FANCA gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 8896563, 10094191, 19423727, 21273304; Invitae). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. 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. This sequence change falls in intron 7 of the FANCA gene. It does not directly change the encoded amino acid sequence of the FANCA protein. RNA analysis indicates that this variant induces altered splicing and likely results in the gain of 10 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with Fanconi anemia (PMID: 8896563, 21273304; Invitae). This variant is also known as 740+5G>T. ClinVar contains an entry for this variant (Variation ID: 237056). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in the activation of a cryptic splice site in intron 7 (PMID: 8896563, 21273304). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.67
CADD	Benign	17
DANN	Benign	0.71
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.74		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.74		Position offset: 5

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

Publications

LitVar

Other links and lift over

dbSNP: rs759877008; hg19: chr16-89871683;