chr17-31235963-C-T

Position:

• chr17-31235963-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_001042492.3(NF1):​c.3916C>T​(p.Arg1306Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,808 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: 31)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:16 U:1
• Conservation: PhyloP100: 3.40

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 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-31235963-C-T is Pathogenic according to our data. Variant chr17-31235963-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 404592.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31235963-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3916C>T	p.Arg1306Ter	stop_gained	29/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3916C>T	p.Arg1306Ter	stop_gained	29/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3916C>T	p.Arg1306Ter	stop_gained	29/58	1	NM_001042492.3	ENSP00000351015	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251422 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135894

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

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: 6.84e-7 AC: 1 AN: 1461808 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727208

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:16 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:8 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 26, 2024	This sequence change creates a premature translational stop signal (p.Arg1306*) 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 (no rsID available, gnomAD 0.0009%). This premature translational stop signal has been observed in individuals with neurofibromatosis type 1 (PMID: 9783703, 10712197, 15146469, 16835897, 16944272, 26969325). ClinVar contains an entry for this variant (Variation ID: 404592). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Oct 26, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 31, 2020	Variant summary: NF1 c.3916C>T (p.Arg1306X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4e-06 in 251422 control chromosomes. c.3916C>T has been reported in the literature in multiple individuals affected with Neurofibromatosis Type 1 (Fahsold_2000, Sabbagh_2013). These data indicate that the variant is very likely to be associated with disease. Seven clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation (pathongenic n=6, VUS n=1). Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Genomics Laboratory, Washington University in St. Louis	Aug 27, 2023	The NF1 c.3916C>T (p.Arg1306Ter) variant was identified at near heterozygous allelic fraction. This variant leads to a premature termination codon, which is predicted to lead to nonsense mediated decay. It has been reported in several individuals affected with neurofibromatosis type 1 (Sabbagh A et al., PMID: 23913538; Chen L et al., PMID: 31347283; Wiest V et al., PMID: 14635100; Thomas L et al., PMID: 22108604; Zhu G et al., PMID: 31533797). This variant has been reported as a somatic variant in 13 cases in the cancer database COSMIC and has been reported in the ClinVar database as pathogenic by 12 submitters (ClinVar ID: 404592). The NF1 c.3916C>T (p.Arg1306Ter) variant is absent from the general population (gnomAD v.3.1.2), indicating it is not a common variant. Based on available information, and based on ACMG/AMP guidelines for variant interpretation (Richards S et al., PMID: 25741868), the NF1 c.3916C>T (p.Arg1306Ter) variant is classified as pathogenic and clinically significant. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	May 02, 2023	- -
Uncertain significance, no assertion criteria provided	clinical testing	Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City	Feb 05, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital	Feb 03, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Center for Human Genetics, Inc, Center for Human Genetics, Inc	Nov 01, 2016	- -

not provided Pathogenic:5

Pathogenic, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Oct 01, 2022	NF1: PVS1, PM2, PS4:Moderate -
Pathogenic, criteria provided, single submitter	clinical testing	Blueprint Genetics	Aug 24, 2018	- -
Pathogenic, criteria provided, single submitter	clinical testing	Athena Diagnostics	May 14, 2020	The variant creates a premature nonsense codon, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and found in general population data at a frequency that is consistent with pathogenicity. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jan 08, 2024	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 (PMID: 9783703); This variant is associated with the following publications: (PMID: 31066482, 28955729, 34418705, 31533797, 29922827, 32164600, 25525159, 16835897, 16944272, 10712197, 15146469, 12112660, 11735023, 12552569, 22155606, 26969325, 30530636, 29957862, 9783703, 31347283, 31370276, 30877234, 29625052, 31776437, Krat[case reeport], 33593231, 34694046, 33877690, 35418823, 27535533, 30308447) -
Pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 14, 2020	The variant creates a premature nonsense codon, and is therefore predicted to result in the loss of a functional protein. Found in at least one patient with expected phenotype for this gene, and found in general population data at a frequency that is consistent with pathogenicity. -

Neurofibromatosis, type 1;C4024216:Tibial pseudarthrosis Pathogenic:1

Pathogenic, criteria provided, single submitter

research

The Laboratory of Genetics and Metabolism, Hunan Children’s Hospital

Nov 10, 2018

- -

Juvenile myelomonocytic leukemia Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Baylor Genetics

Apr 14, 2023

- -

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

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 23, 2019

The p.R1306* pathogenic mutation (also known as c.3916C>T), located in coding exon 29 of the NF1 gene, results from a C to T substitution at nucleotide position 3916. This changes the amino acid from an arginine to a stop codon within coding exon 29. This mutation has been detected in several individuals, once as a de novo occurrence, meeting NIH diagnostic criteria for Neurofibromatosis type 1 (NF1) (Marwaha A et al. Br. J. Dermatol., 2018 Nov;179:1216-1217, Tsipi M et al. J. Neurol. Sci., 2018 Dec;395:95-105).Park VM et al. J. Med. Genet., 1998 Oct;35:813-20; Fahsold R et al. Am. J. Hum. Genet., 2000 Mar;66:790-818; Lee MJ et al. Hum Mutat. 2006 Aug;27(8):832; Hutter S et al. Hum Genet. 2016 May;135(5):469-75). In addition to the clinical data presented in the literature, this alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Uncertain	0.64
Eigen_PC	Uncertain	0.49
FATHMM_MKL	Uncertain	0.91	D
MutationTaster	Benign	1.0	A;A
Vest4		0.98
GERP RS		2.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs376576925; hg19: chr17-29562981; COSMIC: COSV62193951;