17-31337861-T-C

Position:

• chr17-31337861-T-C

Variant summary

Our verdict is Pathogenic. Variant got 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_001042492.3(NF1):​c.6685T>C​(p.Trp2229Arg) 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. 12/21 in silico tools predict a damaging 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. W2229C) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 7.39

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 19 ACMG points.

• PM1: In a helix (size 12) in uniprot entity NF1_HUMAN there are 6 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 chr17-31337861-T-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1702857.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, 0.956
• PP5: Variant 17-31337861-T-C is Pathogenic according to our data. Variant chr17-31337861-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 404554.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.6685T>C	p.Trp2229Arg	missense_variant	44/58	ENST00000358273.9
NF1	NM_000267.3	c.6622T>C	p.Trp2208Arg	missense_variant	43/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.6685T>C	p.Trp2229Arg	missense_variant	44/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Dec 18, 2018	This sequence change replaces tryptophan with arginine at codon 2208 of the NF1 protein (p.Trp2208Arg). The tryptophan residue is moderately conserved and there is a moderate physicochemical difference between tryptophan and arginine. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has been observed in an individual affected with neurofibromatosis type 1 (NF1) (external communication). It has also been observed to segregate with clinical features of NF1 in a family (Invitae). ClinVar contains an entry for this variant (Variation ID: 404554). This variant is not present in population databases (ExAC no frequency). -
Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

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

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 21, 2023

The p.W2208R variant (also known as c.6622T>C), located in coding exon 43 of the NF1 gene, results from a T to C substitution at nucleotide position 6622. The tryptophan at codon 2208 is replaced by arginine, an amino acid with dissimilar properties. The variant was detected in multiple individuals with a clinical or suspected diagnosis of neurofibromatosis type 1 and co-segregated with disease in one family, and has been observed in additional individuals with a personal and/or family history that is consistent with NF1-related disease (Ambry internal data). This missense alteration is located in a region that has a low rate of benign missense variation (Lek M et al. Nature. 2016 Aug 18;536(7616):285-91; DECIPHER: Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources. Firth H.V. et al. 2009. Am.J.Hum.Genet. 84, 524-533). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 23, 2020

The p.W2229R variant (also known as c.6685T>C), located in coding exon 43 of the NF1 gene, results from a T to C substitution at nucleotide position 6622. The tryptophan at codon 2208 is replaced by arginine, an amino acid with dissimilar properties. The variant was detected in multiple individuals with a clinical or suspected diagnosis of neurofibromatosis type 1 and co-segregated with disease in one family (Ambry internal data). This missense alteration is located in a region that has a low rate of benign missense variation (Lek M et al. Nature. 2016 Aug 18;536(7616):285-91; DECIPHER: Database of Chromosomal Imbalance and Phenotype in Humans using Ensembl Resources. Firth H.V. et al. 2009. Am.J.Hum.Genet. 84, 524-533). This variant was not reported in population-based cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	1.0
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D;.;D
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Pathogenic	0.72	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Uncertain	0.081	D
MutationAssessor	Pathogenic	3.1	M;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-12	D;D;D
REVEL	Pathogenic	0.70
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.99
MutPred		0.76		Loss of ubiquitination at K2224 (P = 0.0506);.;.;
MVP		0.91
MPC		3.1
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.94
gMVP		0.98

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: rs1060500342; hg19: chr17-29664879;