NM_001042492.3:c.2294G>T

Variant names:

• chr17-31227260-G-T
• rs199474777
• NM_001042492.3:c.2294G>T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_001042492.3(NF1):​c.2294G>T​(p.Arg765Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,410 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 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. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R765H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 9.48
• Publications: 24 publications found

Genes affected

NF1 (HGNC:7765): (neurofibromin 1) This gene product appears to function as a negative regulator of the ras signal transduction pathway. Mutations in this gene have been linked to neurofibromatosis type 1, juvenile myelomonocytic leukemia and Watson syndrome. The mRNA for this gene is subject to RNA editing (CGA>UGA->Arg1306Term) resulting in premature translation termination. Alternatively spliced transcript variants encoding different isoforms have also been described for this gene. [provided by RefSeq, Jul 2008]

NF1 Gene-Disease associations (from GenCC):

• neurofibromatosis type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Genomics England PanelApp
• neurofibromatosis-Noonan syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
• Moyamoya disease

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial ovarian cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 29 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.767

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001042492.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	NM_001042492.3	MANE Select	c.2294G>T	p.Arg765Leu	missense	Exon 19 of 58	NP_001035957.1
	NF1	NM_000267.4		c.2294G>T	p.Arg765Leu	missense	Exon 19 of 57	NP_000258.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	ENST00000358273.9	TSL:1 MANE Select	c.2294G>T	p.Arg765Leu	missense	Exon 19 of 58	ENSP00000351015.4
	NF1	ENST00000356175.7	TSL:1	c.2294G>T	p.Arg765Leu	missense	Exon 19 of 57	ENSP00000348498.3
	NF1	ENST00000579081.6	TSL:1	n.2294G>T		non_coding_transcript_exon	Exon 19 of 58	ENSP00000462408.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000399 AC: 1 AN: 250754 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461410 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 727024

African (AFR) AF: 0.00 AC: 0 AN: 33446

American (AMR) AF: 0.00 AC: 0 AN: 44694

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.0000252 AC: 1 AN: 39694

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111666

Other (OTH) AF: 0.00 AC: 0 AN: 60360

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Mar 15, 2022

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Dec 27, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 765 of the NF1 protein (p.Arg765Leu). This variant is present in population databases (no rsID available, gnomAD 0.006%). This variant has not been reported in the literature in individuals affected with NF1-related conditions. ClinVar contains an entry for this variant (Variation ID: 561704). 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 expected to disrupt NF1 protein function with a positive predictive value of 80%. 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.

not provided Uncertain:2

Dec 11, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The R765L variant in the NF1 gene has not, to our knowledge, been published in the literature as pathogenic or benign. This variant was not observed in large population cohorts (Lek et al., 2016). Since Arginine and Leucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. This substitution is located within the GTPase activating protein domain (Luo et al., 2014). In-silico analyses, including protein predictors and evolutionary conservation, support a deleterious effect. Based on currently available evidence, we consider R765L to be a variant of uncertain significance.

Sep 25, 2024

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NF1 c.2294G>T (p.Arg765Leu) variant has been reported in the published literature in an individual with breast cancer (PMID: 33471991 (2021), see also LOVD (http://databases.lovd.nl/shared)). This variant has also been observed in reportedly healthy individuals (PMID: 30287823 (2018), 33471991 (2021), 36243179 (2022), see also LOVD (http://databases.lovd.nl/shared)). The frequency of this variant in the general population, 0.000004 (1/250754 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, we are unable to determine the clinical significance of this variant.

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Uncertain:1

Sep 09, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R765L variant (also known as c.2294G>T), located in coding exon 19 of the NF1 gene, results from a G to T substitution at nucleotide position 2294. The arginine at codon 765 is replaced by leucine, an amino acid with dissimilar properties. This alteration was observed with an allele frequency of 0 in 7,051 unselected female breast cancer patients and was observed with an allele frequency of 0.00009 in 11,241 female controls of Japanese ancestry (Momozawa Y et al. Nat Commun, 2018 10;9:4083). This variant was also detected in a cohort of Chinese breast cancer patients (Chen B et al. Aging (Albany NY), 2020 02;12:3140-3155). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Pathogenic	0.22
CADD	Uncertain	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.86	D
Eigen	Uncertain	0.31
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D
M_CAP	Pathogenic	0.56	D
MetaRNN	Pathogenic	0.77	D
MetaSVM	Benign	-0.75	T
MutationAssessor	Benign	1.6	L
PhyloP100		9.5
PrimateAI	Pathogenic	0.86	D
PROVEAN	Uncertain	-4.3	D
REVEL	Uncertain	0.41
Sift	Uncertain	0.0060	D
Sift4G	Benign	0.23	T
Polyphen		0.29	B
Vest4		0.91
MutPred		0.41		Loss of MoRF binding (P = 0.0258)
MVP		0.92
MPC		1.1
ClinPred		0.96	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.49
gMVP		0.74
Mutation Taster		=35/65	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs199474777; hg19: chr17-29554278; COSMIC: COSV62224447; COSMIC: COSV62224447;