NM_000135.4:c.754_755delGAinsAG

Variant names:

• chr16-89803296-TC-CT
• rs587778324
• NM_000135.4:c.754_755delGAinsAG

Variant summary

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

The NM_000135.4(FANCA):​c.754_755delGAinsAG​(p.Asp252Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. The variant is present in control chromosomes in GnomAd MNV project. The variant allele was found at a frequency of 0.000442 in 125 alleles, including 0 homozygotes. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D252N) has been classified as Likely benign.

• Frequency: GnomAD MNV: 𝑓 0.00044 Genomes: not found (cov: 32)
• Consequence: FANCA NM_000135.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6 B:1 O:1
• Conservation: PhyloP100: 0.599
• Publications: 1 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 0 ACMG points.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
FANCA	NM_000135.4	c.754_755delGAinsAG	p.Asp252Ser	missense_variant		ENST00000389301.8	NP_000126.2
FANCA	NM_001286167.3	c.754_755delGAinsAG	p.Asp252Ser	missense_variant			NP_001273096.1
FANCA	NM_001018112.3	c.754_755delGAinsAG	p.Asp252Ser	missense_variant			NP_001018122.1
FANCA	NM_001351830.2	c.658_659delGAinsAG	p.Asp220Ser	missense_variant			NP_001338759.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
FANCA	ENST00000389301.8	c.754_755delGAinsAG	p.Asp252Ser	missense_variant		1	NM_000135.4	ENSP00000373952.3

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

GnomAD MNV AF: 0.000442 AC: 125 Hom.: 0

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6 Benign:1 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:2 Benign:1

Feb 04, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 18, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Dec 01, 2022

Mayo Clinic Laboratories, Mayo Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2 -

Fanconi anemia Uncertain:2

Oct 08, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with serine, which is neutral and polar, at codon 252 of the FANCA protein (p.Asp252Ser). This variant is present in population databases (rs587778324, gnomAD 4%), and has an allele count higher than expected for a pathogenic variant. 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: 134291). 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: "Not Available"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Not Available"). 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. -

Jul 08, 2021

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The FANCA c.754_755delinsAG (p.Asp252Ser) missense change is absent in gnomAD v2.1.1 (PM2_Supporting; https://gnomad.broadinstitute.org/). In silico tools predict a benign effect of this variant on protein function (BP4), but to our knowledge these predictions have not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with Fanconi anemia. In summary, this variant meets criteria to be classified as of uncertain significance based on the ACMG/AMP criteria: PM2_Supporting, BP4. -

Fanconi anemia complementation group A Uncertain:2

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 30, 2023

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The FANCA c.754_755delinsAG (p.Asp252Ser) change is absent in gnomAD v2.1.1 (https://gnomad.broadinstitute.org/). In silico tools predict a benign effect of this variant on protein function, but these predictions have not been confirmed by functional studies. This variant has not been reported in individuals with Fanconi anemia. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

not specified Other:1

Sep 19, 2013

ITMI

Significance: not provided

Review Status: no classification provided

Collection Method: reference population

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.60
Mutation Taster		=62/38	polymorphism

Splicing

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

Other links and lift over

dbSNP: rs587778324; hg19: chr16-89869704; COSMIC: COSV104699335;