17-31232126-C-G

Variant names:

• chr17-31232126-C-G
• rs1164081667
• NM_001042492.3:c.3251C>G

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PM5 PP3_Moderate PP5_Very_Strong

The NM_001042492.3(NF1):​c.3251C>G​(p.Pro1084Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P1084A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 29)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.49
• Publications: 1 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: Pathogenic. The variant received 16 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 29 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-31232125-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 839012.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.885
• PP5: Variant 17-31232126-C-G is Pathogenic according to our data. Variant chr17-31232126-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 1199076.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3251C>G	p.Pro1084Arg	missense_variant	Exon 25 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.4	c.3251C>G	p.Pro1084Arg	missense_variant	Exon 25 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3251C>G	p.Pro1084Arg	missense_variant	Exon 25 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 29

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:2

Mar 15, 2022

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 12, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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: 1199076). This missense change has been observed in individual(s) with clinical features of neurofibromatosis type 1 (PMID: 23656349, 30014477, 31776437). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 1084 of the NF1 protein (p.Pro1084Arg). For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Pro1084 amino acid residue in NF1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 23656349, 28422438, 29673180; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. -

NF1-related disorder Pathogenic:1

Jul 11, 2023

PreventionGenetics, part of Exact Sciences

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NF1 c.3251C>G variant is predicted to result in the amino acid substitution p.Pro1084Arg. This variant was reported in unrelated individuals with neurofibromatosis type 1 (Kang E et al 2019. PubMed ID: 31776437; Palma Milla C et al 2018. PubMed ID: 30014477). This variant has not been reported in a large population database (http://gnomad.broadinstitute.org), indicating this variant is rare. Additionally, different amino acid substitutions affecting the same amino acid (p.Pro1084Ser and p.Pro1084His) have been reported in individuals with neurofibromatosis type 1 (Human Gene Mutation Database). This variant is interpreted as likely pathogenic. -

not provided Pathogenic:1

Jun 16, 2025

GeneDx

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Observed in individuals with neurofibromatosis type 1 and an individual with Noonan syndrome in the published literature (PMID: 30556322, 30014477, 31776437); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 23656349, 30556322, 30014477, 25486365, 2121369, 28422438, 31776437, 33599171, 35353986, 38088145, 29673180) -

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

May 10, 2021

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.P1084R variant (also known as c.3251C>G), located in coding exon 25 of the NF1 gene, results from a C to G substitution at nucleotide position 3251. The proline at codon 1084 is replaced by arginine, an amino acid with dissimilar properties. This variant has been reported in two individuals with a clinical diagnosis of neurofibromatosis (Palma Milla C et al. Ann Hum Genet, 2018 11;82:425-436; Kang E et al. J Hum Genet, 2020 Jan;65:79-89). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.13
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D;.;D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.89	D;D;D
MetaSVM	Benign	-0.86	T
MutationAssessor	Pathogenic	3.2	M;M;.
PhyloP100		7.5
PrimateAI	Pathogenic	0.85	D
PROVEAN	Pathogenic	-6.6	D;D;D
REVEL	Uncertain	0.64
Sift	Uncertain	0.0020	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.92
MutPred		0.44		Loss of glycosylation at P1084 (P = 0.0252);Loss of glycosylation at P1084 (P = 0.0252);.;
MVP		0.74
MPC		1.3
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.72
gMVP		0.69
Mutation Taster		=9/91	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1164081667; hg19: chr17-29559144;