17-31249019-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_001042492.3(NF1):c.4010G>T(p.Arg1337Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000658 in 152,002 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1337Q) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.21

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 4 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, 17 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=0.40963662).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.4010G>T	p.Arg1337Leu	missense_variant	30/58	ENST00000358273.9
NF1	NM_000267.3	c.4010G>T	p.Arg1337Leu	missense_variant	30/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.4010G>T	p.Arg1337Leu	missense_variant	30/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152002 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

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152002 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74248

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: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Aug 26, 2016

This variant is denoted NF1 c.4010G>T at the cDNA level, p.Arg1337Leu (R1337L) at the protein level, and results in the change of an Arginine to a Leucine (CGG>CTG). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. NF1 Arg1337Leu was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, suggesting it is not a common benign variant in these populations. Since Arginine and Leucine differ in polarity, charge, size or other properties, this is considered a non-conservative amino acid substitution. NF1 Arg1337Leu occurs at a position that is conserved in mammals and is located within the Ras-GAP domain (UniProt). In silico analyses predict that this variant is probably damaging to protein structure and function. Based on currently available evidence, it is unclear whether NF1 Arg1337Leu is a pathogenic or benign variant. We consider it to be a variant of uncertain significance. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 22, 2020

The p.R1337L variant (also known as c.4010G>T), located in coding exon 30 of the NF1 gene, results from a G to T substitution at nucleotide position 4010. The arginine at codon 1337 is replaced by leucine, an amino acid with dissimilar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Uncertain	0.10	D
BayesDel_noAF	Benign	-0.090
Cadd	Uncertain	23
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.79	D;.;D
Eigen	Benign	-0.020
Eigen_PC	Benign	0.14
FATHMM_MKL	Benign	0.70	D
LIST_S2	Uncertain	0.96	D;D;D
M_CAP	Uncertain	0.23	D
MetaRNN	Benign	0.41	T;T;T
MetaSVM	Benign	-0.45	T
MutationAssessor	Benign	0.94	L;L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.51	T
PROVEAN	Uncertain	-3.1	D;D;D
REVEL	Uncertain	0.44
Sift	Benign	0.29	T;T;T
Sift4G	Benign	0.17	T;T;T
Polyphen		0.22	B;B;.
Vest4		0.70
MutPred		0.47		Loss of disorder (P = 0.0547);Loss of disorder (P = 0.0547);.;
MVP		0.84
MPC		0.96
ClinPred		0.85	D
GERP RS		4.8
Varity_R		0.55
gMVP		0.56

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs1060500379; hg19: chr17-29576037;