17-31206297-C-T

Variant names:

• chr17-31206297-C-T
• rs778405030
• NM_001042492.3:c.1318C>T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1 PP5_Very_Strong

The NM_001042492.3(NF1):​c.1318C>T​(p.Arg440*) variant causes a stop gained change. The variant allele was found at a frequency of 0.00000479 in 1,461,612 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: NF1 NM_001042492.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:24
• Conservation: PhyloP100: 5.78

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 Pathogenic. Variant got 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PP5: Variant 17-31206297-C-T is Pathogenic according to our data. Variant chr17-31206297-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 230673.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31206297-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.1318C>T	p.Arg440*	stop_gained	Exon 12 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.1318C>T	p.Arg440*	stop_gained	Exon 12 of 57		NP_000258.1
NF1	NM_001128147.3	c.1318C>T	p.Arg440*	stop_gained	Exon 12 of 15		NP_001121619.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.1318C>T	p.Arg440*	stop_gained	Exon 12 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251412 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135868

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

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 AF: 0.00000479 AC: 7 AN: 1461612 Hom.: 0 Cov.: 32 AF XY: 0.00000688 AC XY: 5 AN XY: 727120

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:24

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:12

Feb 03, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg440*) in the NF1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NF1 are known to be pathogenic (PMID: 10712197, 23913538). This variant is present in population databases (rs778405030, gnomAD 0.006%). This premature translational stop signal has been observed in individuals with neurofibromatosis type 1 (PMID: 7655472, 10543400, 10712197, 10862084, 16835897, 23668869, 24922668). ClinVar contains an entry for this variant (Variation ID: 230673). For these reasons, this variant has been classified as Pathogenic. -

Apr 10, 2020

Division Of Personalized Genomic Medicine, Columbia University Irving Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c. 1318C>T variant is a heterozygous single base pair substitution at nucleotide 1318 in exon 12 of 58 of the NF1 gene, resulting in a premature translational stop signal at amino acid 440 of 2840 (p.Arg440Ter), and is expected to cause nonsense mediated mRNA decay. This variant is observed in the Genome Aggregation Database (gnomAD) at a very low frequency (2/251,412), indicating it is not a common benign variant in the populations represented in this database. This variant has been observed in the heterozygous state in multiple individuals with clinical features of Neurofibromatosis, type 1 (PMIDs: 24232412, 30530636, 7655472, 23668869, 16835897, 10862084, 10543400, 10712197, and 24922668). This variant has been reported in ClinVar as Pathogenic by multiple submitters (Variation ID: 230673; Last accessed: 3/25/2020). -

Mar 04, 2025

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Criteria applied: PVS1,PP4,PM2_SUP -

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Oct 26, 2020

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 20, 2019

Medical Genetics, University of Parma

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 19, 2023

Institute of Medical Genetics and Applied Genomics, University Hospital Tübingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 15, 2022

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 09, 2021

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Apr 04, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 11, 2024

NHS Central & South Genomic Laboratory Hub

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jun 01, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: <0.001%). Predicted Consequence/Location: Stop-gained (nonsense): predicted to result in a loss or disruption of normal protein function through nonsense-mediated decay (NMD) or protein truncation. Multiple pathogenic variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000230673 /PMID: 7655472). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

not provided Pathogenic:7

Feb 16, 2022

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 7655472, 11940628, 16835897, 31212687, 31717729, 25525159, 10712197, 26744134, 28454108, 9452037, 15060124, 10862084, 30014477, 10336779, 23668869, 14517963, 24232412, 25925892, 10543400, 30713041, 30290804, 31370276, 30530636, 31730495, 31776437, 29625052) -

-

Clinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Jul 14, 2021

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant has been identified in at least one individual with clinical features associated with this gene. -

Jul 14, 2021

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant causes the premature termination of NF1 protein synthesis. In addition, this variant has been reported as pathogenic in individuals with Neurofibromatosis type 1 in the published literature (PMIDs: 7655472 (1995), 15060124 (2004), and 23668869 (2013)). Based on the available information, this variant is classified as pathogenic. -

Sep 05, 2023

Mayo Clinic Laboratories, Mayo Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP4, PM2_moderate, PS2, PVS1 -

-

Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 14, 2024

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NF1 c.1318C>T; p.Arg440Ter variant (rs778405030) is reported in several individuals affected with neurofibromatosis type 1 (Hirbe 2015, Stewart 2014). It is listed in the ClinVar database (Variation ID: 230673), and is only observed on two alleles in the Genome Aggregation Database, indicating it is not a common polymorphism. This variant induces an early termination codon and is predicted to result in a truncated protein or mRNA subject to nonsense-mediated decay. Based on available information, this variant is considered to be pathogenic. References: Hirbe AC et al. Whole Exome Sequencing Reveals the Order of Genetic Changes during Malignant Transformation and Metastasis in a Single Patient with NF1-plexiform Neurofibroma. Clin Cancer Res. 2015 Sep 15;21(18):4201-11. PMID: 25925892. Stewart DR et al. Jaffe-Campanacci syndrome, revisited: detailed clinical and molecular analyses determine whether patients have neurofibromatosis type 1, coincidental manifestations, or a distinct disorder. Genet Med. 2014 Jun;16(6):448-59. PMID: 24232412. -

Neurofibrmatosis type 1 Pathogenic:1

Oct 07, 2021

Laboratory of Medical Genetics Unit, Bambino Gesù Children's Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Abnormality of the skin Pathogenic:1

Jul 10, 2021

Kariminejad - Najmabadi Pathology & Genetics Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Mar 09, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Juvenile myelomonocytic leukemia Pathogenic:1

Aug 06, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Pathogenic:1

Mar 04, 2015

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

​<span style="background-color:initial">The p.R440* pathogenic mutation (also known as c.1318C>T), located in coding exon 12 of the NF1 gene, results from a C to T substitution at nucleotide position 1318. This changes the amino acid from an arginine to a stop codon within exon 12. This mutation has been reported in several individuals diagnosed with NF1 (Heim et al. Hum Mol Genet. 1995. 4(6):975-981; Fahsold et al. Am J Hum Genet. 2000. 66:790-818; Kluwe, et al. Hum Mutat. 2003 Nov;22(5):420). In addition to the clinical data presented in the literature, since premature stop codons are typically deleterious in nature, p.R440* is interpreted as a disease-causing mutation (ACMG Recommendations for Standards for Interpretation and Reporting of Sequence Variations. Revision 2007. Genet Med 2008;10:294). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.98, 0.98, 0.99
GERP RS		5.2

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: rs778405030; hg19: chr17-29533315; COSMIC: COSV62197118;