16-89767141-C-G

Variant names:

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

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000135.4(FANCA):​c.2601G>C​(p.Lys867Asn) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Synonymous variant affecting the same amino acid position (i.e. K867K) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: FANCA NM_000135.4 missense, splice_region
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts 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: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 22 uncertain in NM_000135.4
• 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>C	p.Lys867Asn	missense_variant, splice_region_variant	Exon 27 of 43	ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.2601G>C	p.Lys867Asn	missense_variant, splice_region_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>C	p.Lys867Asn	missense_variant, splice_region_variant	Exon 27 of 43	1	NM_000135.4	ENSP00000373952.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Fanconi anemia Uncertain:1

Aug 28, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine with asparagine at codon 867 of the FANCA protein (p.Lys867Asn). The lysine residue is highly conserved and there is a moderate physicochemical difference between lysine and asparagine. 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 not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with FANCA-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). 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 may disrupt the consensus 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. -

Fanconi anemia complementation group A Uncertain:1

Apr 05, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.89
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.060
CADD	Pathogenic	48
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.70	D;.
Eigen	Uncertain	0.37
Eigen_PC	Uncertain	0.32
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Benign	0.76	T;T
M_CAP	Uncertain	0.28	D
MetaRNN	Uncertain	0.71	D;D
MetaSVM	Uncertain	0.53	D
MutationAssessor	Uncertain	2.6	M;M
PhyloP100		4.5
PrimateAI	Uncertain	0.53	T
PROVEAN	Uncertain	-3.5	D;D
REVEL	Uncertain	0.59
Sift	Uncertain	0.0020	D;D
Sift4G	Uncertain	0.0060	D;D
Polyphen		0.89	P;.
Vest4		0.66
MutPred		0.38		Loss of methylation at K867 (P = 0.0063);Loss of methylation at K867 (P = 0.0063);
MVP		0.97
ClinPred		0.92	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.69
gMVP		0.64
Mutation Taster		=34/66	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.42		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.42		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;