17-31259077-C-G

Variant names:

• chr17-31259077-C-G
• rs377295676
• NM_001042492.3:c.4378C>G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001042492.3(NF1):​c.4378C>G​(p.His1460Asp) variant causes a missense change. The variant allele was found at a frequency of 0.00000657 in 152,106 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 Conflicting classifications of pathogenicity (no stars).

• 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 P:1 U:3
• Conservation: PhyloP100: 4.53

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.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the NF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 399 curated pathogenic missense variants (we use a threshold of 10). The gene has 143 curated benign missense variants. Gene score misZ: 6.5427 (above the threshold of 3.09). Trascript score misZ: 8.4054 (above the threshold of 3.09). GenCC associations: The gene is linked to neurofibromatosis, familial spinal, hereditary pheochromocytoma-paraganglioma, neurofibromatosis type 1, Watson syndrome, neurofibromatosis-Noonan syndrome, Moyamoya disease, familial ovarian cancer.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.832

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4378C>G	p.His1460Asp	missense_variant	Exon 33 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.4315C>G	p.His1439Asp	missense_variant	Exon 32 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4378C>G	p.His1460Asp	missense_variant	Exon 33 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152106 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.: 30

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152106 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74296

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

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:1

Feb 03, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.His1439 amino acid residue in NF1. Other variant(s) that disrupt this residue have been observed in individuals with NF1-related conditions (PMID: 23668869, 27716896), which suggests that this may be a clinically significant amino acid residue. 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. ClinVar contains an entry for this variant (Variation ID: 1029751). This missense change has been observed in individual(s) with clinical features of neurofibromatosis, type 1 (Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces histidine, which is basic and polar, with aspartic acid, which is acidic and polar, at codon 1439 of the NF1 protein (p.His1439Asp). -

not provided Uncertain:1

Jul 28, 2020

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In silico analysis supports that this missense variant has a deleterious effect on protein structure/function Has not been previously published as pathogenic or benign to our knowledge Not observed in large population cohorts (Lek 2016) -

Café-au-lait macules with pulmonary stenosis Uncertain:1

Nov 30, 2020

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was determined to be of uncertain significance according to ACMG Guidelines, 2015 [PMID:25741868]. -

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

Feb 01, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.H1439D variant (also known as c.4315C>G), located in coding exon 32 of the NF1 gene, results from a C to G substitution at nucleotide position 4315. The histidine at codon 1439 is replaced by aspartic acid, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Uncertain	23
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.94	D;.;T
Eigen	Benign	0.13
Eigen_PC	Benign	0.21
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.92	D;D;D
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.83	D;D;D
MetaSVM	Uncertain	0.095	D
MutationAssessor	Uncertain	2.3	M;.;.
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-7.2	D;D;D
REVEL	Uncertain	0.60
Sift	Uncertain	0.0060	D;D;D
Sift4G	Uncertain	0.010	D;D;D
Polyphen		0.045	B;B;.
Vest4		0.85
MutPred		0.67		Gain of ubiquitination at K1457 (P = 0.0605);.;.;
MVP		0.89
MPC		0.98
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.98
gMVP		0.94

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: rs377295676; hg19: chr17-29586095;