rs199474758

chr17-31221854-T-C

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_001042492.3(NF1):c.1646T>C(p.Leu549Pro) 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. 13/21 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. L549R) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3 O:1
• Conservation: PhyloP100: 7.64

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 17 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain 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 chr17-31221854-T-G is described in ClinVar as [Pathogenic]. Clinvar id is 2821334.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant where missense usually causes diseases, NF1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.909
• PP5: Variant 17-31221854-T-C is Pathogenic according to our data. Variant chr17-31221854-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 68303.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31221854-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.1646T>C	p.Leu549Pro	missense_variant	15/58	ENST00000358273.9
NF1	NM_000267.3	c.1646T>C	p.Leu549Pro	missense_variant	15/57
NF1	NM_001128147.3	c.1646T>C	p.Leu549Pro	missense_variant	15/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.1646T>C	p.Leu549Pro	missense_variant	15/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 19, 2022	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: 68303). This missense change has been observed in individual(s) with neurofibromatosis type 1 (NF1) and NF1 (PMID: 10712197, 21520333; Invitae). In at least one individual the variant was observed to be de novo. It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 549 of the NF1 protein (p.Leu549Pro). -

not provided Pathogenic:1 Other:1

not provided, no classification provided	literature only	UniProtKB/Swiss-Prot	-	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	May 26, 2022	Not observed in large population cohorts (gnomAD); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 10712197, 24803665, 23447461, 24789688, 25486365, Bahsi2020[article], 34418705, 21520333, 31201679) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
Cadd	Pathogenic	27
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D;.;.;D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D;D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.91	D;D;D;D
MetaSVM	Uncertain	0.35	D
MutationAssessor	Uncertain	2.4	M;M;M;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.5	D;D;D;D
REVEL	Pathogenic	0.82
Sift	Uncertain	0.0010	D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D
Polyphen		1.0	D;D;.;.
Vest4		0.98
MutPred		0.67		Gain of loop (P = 0.0051);Gain of loop (P = 0.0051);Gain of loop (P = 0.0051);.;
MVP		0.95
MPC		2.2
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.89
gMVP		0.99

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: rs199474758; hg19: chr17-29548872;