16-89740803-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_Moderate PM2 PP3_Strong PP5_Very_Strong

The NM_000135.4(FANCA):c.3828+1G>A variant causes a splice donor change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,886 control chromosomes in the GnomAD database, with no homozygous occurrence. 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)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FANCA NM_000135.4 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 2.00

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]

ZNF276 (HGNC:23330): (zinc finger protein 276) Enables sequence-specific double-stranded DNA binding activity. Predicted to be involved in regulation of transcription by RNA polymerase II. Located in kinetochore. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PVS1: Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.014194139 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.2, offset of 24, new splice context is: aagGTgtcc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.
• 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 16-89740803-C-T is Pathogenic according to our data. Variant chr16-89740803-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 555597.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
FANCA	NM_000135.4	c.3828+1G>A		splice_donor_variant		ENST00000389301.8
ZNF276	NM_001113525.2	c.*2557C>T		3_prime_UTR_variant	11/11	ENST00000443381.7

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
FANCA	ENST00000389301.8	c.3828+1G>A		splice_donor_variant		1	NM_000135.4	P1
ZNF276	ENST00000443381.7	c.*2557C>T		3_prime_UTR_variant	11/11	1	NM_001113525.2	P2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460886 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726746

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia complementation group A Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 07, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	Dec 13, 2017	- -

Fanconi anemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 10, 2023

This sequence change affects a donor splice site in intron 38 of the FANCA gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of Fanconi anemia (PMID: 21273304). ClinVar contains an entry for this variant (Variation ID: 555597). Studies have shown that disruption of this splice site results in skipping of exon 38, but is expected to preserve the integrity of the reading-frame (PMID: 21273304). This variant disrupts a region of the FANCA protein in which other variant(s) (p.Phe1263del) have been determined to be pathogenic (PMID: 9371798, 15643609, 21273304, 21659346). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Benign	-0.071	T
BayesDel_noAF	Benign	-0.34
Cadd	Benign	21
Dann	Benign	0.92
Eigen	Uncertain	0.44
Eigen_PC	Benign	0.12
FATHMM_MKL	Benign	0.70	D
MutationTaster	Benign	1.0	D;D;D
GERP RS		4.3
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	0.77
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.97		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: rs1432988639; hg19: chr16-89807211;