rs764654925

Variant names:

• chr17-31260433-A-C
• rs764654925
• NM_001042492.3:c.4495A>C

Your query was ambiguous. Multiple possible variants found:

• chr17-31260433-A-C
• chr17-31260433-A-G
• chr17-31260433-A-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The NM_001042492.3(NF1):​c.4495A>C​(p.Ile1499Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. I1499V) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 8.69
• Publications: 5 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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4495A>C	p.Ile1499Leu	missense_variant	Exon 34 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.4	c.4432A>C	p.Ile1478Leu	missense_variant	Exon 33 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4495A>C	p.Ile1499Leu	missense_variant	Exon 34 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

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

- -

Aug 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 1478 of the NF1 protein (p.Ile1478Leu). This variant is not present in population databases (gnomAD no frequency). 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: 480184). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on NF1 protein function. 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. -

Neurofibromatosis, type 1;C0349639:Juvenile myelomonocytic leukemia;C0553586:Café-au-lait macules with pulmonary stenosis;C1834235:Neurofibromatosis, familial spinal;C2931482:Neurofibromatosis-Noonan syndrome Uncertain:1

Jun 01, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Oct 23, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.I1478L variant (also known as c.4432A>C), located in coding exon 33 of the NF1 gene, results from an A to C substitution at nucleotide position 4432. The isoleucine at codon 1478 is replaced by leucine, an amino acid with highly similar properties. This amino acid position is highly 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	0.25
BayesDel_addAF	Pathogenic	0.20	D
BayesDel_noAF	Uncertain	0.050
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.58	D;.;T
Eigen	Uncertain	0.34
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Uncertain	0.70	D;D;D
MetaSVM	Uncertain	0.0096	D
MutationAssessor	Benign	1.3	L;.;.
PhyloP100		8.7
PrimateAI	Pathogenic	0.86	D
PROVEAN	Benign	-1.6	N;N;N
REVEL	Uncertain	0.52
Sift	Benign	0.17	T;T;T
Sift4G	Uncertain	0.025	D;D;D
Polyphen		0.60	P;P;.
Vest4		0.58
MutPred		0.51		Gain of sheet (P = 0.0344);.;.;
MVP		0.83
MPC		1.3
ClinPred		0.92	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.42
gMVP		0.67
Mutation Taster		=4/96	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.52		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.52		Position offset: 5

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

Other links and lift over

dbSNP: rs764654925; hg19: chr17-29587451;