17-31227547-T-C

Position:

• chr17-31227547-T-C

Variant summary

Our verdict is Pathogenic. Variant got 23 ACMG points: 23P and 0B. PS1 PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_001042492.3(NF1):​c.2350T>C​(p.Trp784Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,168 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 Likely pathogenic (★★). Another nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin Lovd. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W784C) has been classified as Pathogenic.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6 O:1
• Conservation: PhyloP100: 7.49

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 23 ACMG points.

• PS1: Transcript NM_001042492.3 (NF1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in Lovd
• PM1: In a helix (size 21) in uniprot entity NF1_HUMAN there are 13 pathogenic changes around while only 0 benign (100%) 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 chr17-31227549-G-C is described in Lovd as [Pathogenic].
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), NF1. . Gene score misZ 6.5427 (greater than the threshold 3.09). Trascript score misZ 8.4054 (greater than threshold 3.09). GenCC has associacion of gene with neurofibromatosis, familial spinal, hereditary pheochromocytoma-paraganglioma, neurofibromatosis type 1, Watson syndrome, neurofibromatosis-Noonan syndrome, Moyamoya disease, familial ovarian cancer.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.984
• PP5: Variant 17-31227547-T-C is Pathogenic according to our data. Variant chr17-31227547-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 68318.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31227547-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.2350T>C	p.Trp784Arg	missense_variant	20/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.2350T>C	p.Trp784Arg	missense_variant	20/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.2350T>C	p.Trp784Arg	missense_variant	20/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152168 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152168 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74326

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:4

Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	NHS Central & South Genomic Laboratory Hub	Nov 11, 2024	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	May 23, 2023	For these reasons, this variant has been classified as Pathogenic. 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: 68318). This missense change has been observed in individual(s) with neurofibromatosis type I (PMID: 11857752, 12807981, 15146469, 24789688). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces tryptophan, which is neutral and slightly polar, with arginine, which is basic and polar, at codon 784 of the NF1 protein (p.Trp784Arg). -
Pathogenic, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Oct 26, 2020	- -

not provided Pathogenic:2 Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Jul 21, 2021	Not observed in large population cohorts (Lek 2016); 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: 25486365, 31776437, 27535533, 15146469, 12807981, 24789688, 18484666, 18546366, 11857752, 24803665) -
Pathogenic, criteria provided, single submitter	clinical testing	Greenwood Genetic Center Diagnostic Laboratories, Greenwood Genetic Center	Mar 16, 2021	PS4, PP2, PP3, PM1, PM2, PM5, PM6 -
not provided, no classification provided	literature only	UniProtKB/Swiss-Prot	-	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.27
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.;D
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.66
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.98	D;D;D
MetaSVM	Uncertain	-0.24	T
MutationAssessor	Uncertain	2.4	M;M;.
PrimateAI	Pathogenic	0.89	D
PROVEAN	Pathogenic	-11	D;D;D
REVEL	Pathogenic	0.80
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.98
MutPred		0.86		Gain of disorder (P = 0.0059);Gain of disorder (P = 0.0059);.;
MVP		0.91
MPC		2.3
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.93
gMVP		0.96

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: rs199474730; hg19: chr17-29554565; COSMIC: COSV104662388; COSMIC: COSV104662388;