17-31229118-C-T

Position:

• chr17-31229118-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.2503C>T​(p.Gln835*) variant causes a stop gained 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 (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: NF1 NM_001042492.3 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 7.54

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 (HGNC:):

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 17-31229118-C-T is Pathogenic according to our data. Variant chr17-31229118-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 523904.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31229118-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.2503C>T	p.Gln835*	stop_gained	21/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.2503C>T	p.Gln835*	stop_gained	21/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.2503C>T	p.Gln835*	stop_gained	21/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 1459554 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726078

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:3

Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 25, 2023	This premature translational stop signal has been observed in individual(s) with clinical features of NF1-related conditions (PMID: 21520333). This sequence change creates a premature translational stop signal (p.Gln835*) 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 not present in population databases (gnomAD no frequency). ClinVar contains an entry for this variant (Variation ID: 523904). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Clinical Molecular Genetics Laboratory, Johns Hopkins All Children's Hospital	Nov 16, 2018	- -

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Sep 01, 2021	This nonsense variant causes the premature termination of NF1 protein synthesis. This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). To the best of our knowledge, the variant has not been reported in the published literature. Based on the available information, the variant is predicted to be likely pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jun 27, 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; Not observed at significant frequency in large population cohorts (gnomAD); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.65
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.91
FATHMM_MKL	Pathogenic	0.98	D
Vest4		0.99
GERP RS		5.6

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs1555614207; hg19: chr17-29556136; COSMIC: COSV100645763; COSMIC: COSV100645763;