rs766323701

Positions:

• chr17-31340541-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 5P and 3B. PM1 PM2 PP2 BP4_Moderate BP6

The NM_001042492.3(NF1):​c.6958G>A​(p.Val2320Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,140 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. 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. V2320A) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 3.20

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 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, 15 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1
• BP4: Computational evidence support a benign effect (MetaRNN=0.17298433).
• BP6: Variant 17-31340541-G-A is Benign according to our data. Variant chr17-31340541-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 457814.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.6958G>A	p.Val2320Met	missense_variant	47/58	ENST00000358273.9
NF1	NM_000267.3	c.6895G>A	p.Val2299Met	missense_variant	46/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.6958G>A	p.Val2320Met	missense_variant	47/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251480 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135914

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000879

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74326

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 28, 2022

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. 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 NF1 protein function. ClinVar contains an entry for this variant (Variation ID: 457814). This variant has not been reported in the literature in individuals affected with NF1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with methionine, which is neutral and non-polar, at codon 2299 of the NF1 protein (p.Val2299Met). -

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

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 08, 2024

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.57	D;.;T
Eigen	Benign	-0.14
Eigen_PC	Benign	0.054
FATHMM_MKL	Uncertain	0.78	D
LIST_S2	Uncertain	0.92	D;D;D
M_CAP	Benign	0.054	D
MetaRNN	Benign	0.17	T;T;T
MetaSVM	Benign	-0.94	T
MutationAssessor	Benign	1.8	L;.;.
MutationTaster	Benign	0.96	D;D;D;D
PrimateAI	Uncertain	0.53	T
PROVEAN	Benign	-1.3	N;N;N
REVEL	Benign	0.048
Sift	Benign	0.12	T;T;T
Sift4G	Benign	0.076	T;T;T
Polyphen		0.0030	B;B;.
Vest4		0.14
MutPred		0.39		Gain of catalytic residue at V2320 (P = 0.226);.;.;
MVP		0.45
MPC		0.52
ClinPred		0.79	D
GERP RS		4.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.070
gMVP		0.50

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs766323701; hg19: chr17-29667559;