16-89799178-A-G

Position:

• chr16-89799178-A-G

Variant summary

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

The NM_000135.4(FANCA):​c.881T>C​(p.Ile294Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,876 control chromosomes in the GnomAD database, with no homozygous occurrence. 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)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: FANCA NM_000135.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.462

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=0.027122289).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
FANCA	NM_000135.4	c.881T>C	p.Ile294Thr	missense_variant	10/43	ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.881T>C	p.Ile294Thr	missense_variant	10/43		NP_001273096.1
FANCA	NM_001018112.3	c.881T>C	p.Ile294Thr	missense_variant	10/11		NP_001018122.1
FANCA	NM_001351830.2	c.785T>C	p.Ile262Thr	missense_variant	9/10		NP_001338759.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
FANCA	ENST00000389301.8	c.881T>C	p.Ile294Thr	missense_variant	10/43	1	NM_000135.4	ENSP00000373952.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461876 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727240

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: 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

Aug 28, 2021

This sequence change replaces isoleucine with threonine at codon 294 of the FANCA protein (p.Ile294Thr). The isoleucine residue is weakly conserved and there is a moderate physicochemical difference between isoleucine and threonine. 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. ClinVar contains an entry for this variant (Variation ID: 456140). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect 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	0.051
BayesDel_addAF	Benign	-0.16	T
BayesDel_noAF	Benign	-0.46
CADD	Benign	2.8
DANN	Benign	0.37
DEOGEN2	Benign	0.072	T;.;.;T;T;.
Eigen	Benign	-1.7
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.0032	N
LIST_S2	Benign	0.23	T;T;T;T;T;T
M_CAP	Benign	0.0047	T
MetaRNN	Benign	0.027	T;T;T;T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	-0.90	N;N;N;.;.;.
PrimateAI	Benign	0.28	T
PROVEAN	Benign	0.90	N;N;N;N;N;N
REVEL	Benign	0.26
Sift	Benign	0.27	T;T;T;T;T;T
Sift4G	Benign	0.28	T;T;T;T;T;T
Polyphen		0.0	B;.;B;.;B;B
Vest4		0.038
MutPred		0.38		Gain of disorder (P = 0.0242);Gain of disorder (P = 0.0242);Gain of disorder (P = 0.0242);Gain of disorder (P = 0.0242);Gain of disorder (P = 0.0242);.;
MVP		0.048
ClinPred		0.059	T
GERP RS		-1.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.047
gMVP		0.15

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555566545; hg19: chr16-89865586;