16-89771808-G-T

Variant names:

• chr16-89771808-G-T
• rs17232973
• NM_000135.4:c.2021C>A

Variant summary

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

The NM_000135.4(FANCA):​c.2021C>A​(p.Ser674*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,568 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FANCA NM_000135.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 1.18

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 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 16-89771808-G-T is Pathogenic according to our data. Variant chr16-89771808-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 974234.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr16-89771808-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FANCA	NM_000135.4	c.2021C>A	p.Ser674*	stop_gained	Exon 23 of 43	ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.2021C>A	p.Ser674*	stop_gained	Exon 23 of 43		NP_001273096.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FANCA	ENST00000389301.8	c.2021C>A	p.Ser674*	stop_gained	Exon 23 of 43	1	NM_000135.4	ENSP00000373952.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461568 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727090

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

Aug 10, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 28, 2020

Leiden Open Variation Database

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: curation

Curator: Arleen D. Auerbach. Submitter to LOVD: Sue Richards. -

Fanconi anemia Pathogenic:1

May 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. This sequence change creates a premature translational stop signal (p.Ser674*) in the FANCA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in FANCA are known to be pathogenic (PMID: 19367192). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Fanconi anemia (PMID: 19367192). ClinVar contains an entry for this variant (Variation ID: 974234). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Pathogenic	37
DANN	Uncertain	0.98
Eigen	Benign	0.081
Eigen_PC	Benign	-0.25
FATHMM_MKL	Benign	0.21	N
Vest4		0.77
GERP RS		3.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.32		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.32		Position offset: -2

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

Publications

LitVar

Other links and lift over

dbSNP: rs17232973; hg19: chr16-89838216;