16-89767141-C-T

Variant names:

• chr16-89767141-C-T
• rs746889340
• NM_000135.4:c.2601G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_000135.4(FANCA):​c.2601G>A​(p.Lys867Lys) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.00000137 in 1,455,776 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FANCA NM_000135.4 splice_region, synonymous
• Scores: Splicing: ADA: 0.9770
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 4.54
• Publications: 0 publications found

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]

FANCA Gene-Disease associations (from GenCC):

• Fanconi anemia complementation group A

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Laboratory for Molecular Medicine, ClinGen, Ambry Genetics, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P
• Fanconi anemia

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FANCA	NM_000135.4	c.2601G>A	p.Lys867Lys	splice_region_variant, synonymous_variant	Exon 27 of 43	ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.2601G>A	p.Lys867Lys	splice_region_variant, synonymous_variant	Exon 27 of 43		NP_001273096.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FANCA	ENST00000389301.8	c.2601G>A	p.Lys867Lys	splice_region_variant, synonymous_variant	Exon 27 of 43	1	NM_000135.4	ENSP00000373952.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1455776 Hom.: 0 Cov.: 29 AF XY: 0.00 AC XY: 0 AN XY: 724690

African (AFR) AF: 0.00 AC: 0 AN: 33336

American (AMR) AF: 0.00 AC: 0 AN: 44714

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26102

East Asian (EAS) AF: 0.00 AC: 0 AN: 39654

South Asian (SAS) AF: 0.00 AC: 0 AN: 86114

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53356

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5756

European-Non Finnish (NFE) AF: 0.00000181 AC: 2 AN: 1106544

Other (OTH) AF: 0.00 AC: 0 AN: 60200

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Fanconi anemia Uncertain:2

Aug 17, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Apr 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects codon 867 of the FANCA mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the FANCA protein. This variant also falls at the last nucleotide of exon 27, which is part of the consensus splice site for this exon. This variant is present in population databases (rs746889340, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with FANCA-related conditions. ClinVar contains an entry for this variant (Variation ID: 1027041). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Pathogenic	32
DANN	Benign	0.68
PhyloP100		4.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.98
dbscSNV1_RF	Pathogenic	0.91
SpliceAI score (max)		0.27		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.27		Position offset: 0

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

Other links and lift over

dbSNP: rs746889340; hg19: chr16-89833549;