rs777311234

Positions:

• chr16-89803282-C-A
• chr16-89803282-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_000135.4(FANCA):​c.769G>T​(p.Val257Leu) variant causes a missense 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. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: FANCA NM_000135.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.0940

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 Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.05996117).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FANCA	NM_000135.4	c.769G>T	p.Val257Leu	missense_variant	8/43	ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.769G>T	p.Val257Leu	missense_variant	8/43		NP_001273096.1
FANCA	NM_001018112.3	c.769G>T	p.Val257Leu	missense_variant	8/11		NP_001018122.1
FANCA	NM_001351830.2	c.673G>T	p.Val225Leu	missense_variant	7/10		NP_001338759.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FANCA	ENST00000389301.8	c.769G>T	p.Val257Leu	missense_variant	8/43	1	NM_000135.4	ENSP00000373952	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Fanconi anemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 08, 2021

This sequence change replaces valine with leucine at codon 257 of the FANCA protein (p.Val257Leu). The valine residue is weakly conserved and there is a small physicochemical difference between valine and leucine. This variant is present in population databases (rs777311234, ExAC 0.001%). This variant has not been reported in the literature in individuals affected with FANCA-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt FANCA protein function. 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
AlphaMissense	Benign	0.14
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.65
CADD	Benign	5.7
DANN	Benign	0.50
DEOGEN2	Benign	0.077	T;.;.;T;T;.
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.95
FATHMM_MKL	Benign	0.050	N
LIST_S2	Benign	0.67	T;T;T;T;T;T
M_CAP	Benign	0.0091	T
MetaRNN	Benign	0.060	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.6	L;L;L;.;.;.
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.29	T
PROVEAN	Benign	-0.79	N;N;N;N;N;N
REVEL	Benign	0.029
Sift	Benign	0.85	T;T;T;T;T;T
Sift4G	Benign	0.85	T;T;T;T;T;T
Polyphen		0.024	B;.;B;.;B;B
Vest4		0.075
MutPred		0.15		Gain of ubiquitination at K261 (P = 0.0898);Gain of ubiquitination at K261 (P = 0.0898);Gain of ubiquitination at K261 (P = 0.0898);Gain of ubiquitination at K261 (P = 0.0898);Gain of ubiquitination at K261 (P = 0.0898);.;
MVP		0.51
ClinPred		0.020	T
GERP RS		1.8
Varity_R		0.030
gMVP		0.15

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs777311234; hg19: chr16-89869690;