rs878853903

Variant names:

• chr17-31327791-T-A
• rs878853903
• NM_001042492.3:c.5561T>A

Your query was ambiguous. Multiple possible variants found:

• chr17-31327791-T-A
• chr17-31327791-T-C
• chr17-31327791-T-G

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM2 PM5 PP2 PP3_Strong

The NM_001042492.3(NF1):​c.5561T>A​(p.Leu1854Gln) 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 Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L1854P) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• 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 Likely_pathogenic. Variant got 9 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-31327791-T-C is described in Lovd as [Likely_pathogenic].
• PP2: Missense variant in the NF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 399 curated pathogenic missense variants (we use a threshold of 10). The gene has 143 curated benign missense variants. Gene score misZ: 6.5427 (above the threshold of 3.09). Trascript score misZ: 8.4054 (above the threshold of 3.09). GenCC associations: The gene is linked to 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, 0.955

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.5561T>A	p.Leu1854Gln	missense_variant	Exon 38 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.5498T>A	p.Leu1833Gln	missense_variant	Exon 37 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.5561T>A	p.Leu1854Gln	missense_variant	Exon 38 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:3

Oct 26, 2020

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 15, 2022

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 05, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 sequence change replaces leucine with glutamine at codon 1833 of the NF1 protein (p.Leu1833Gln). The leucine residue is moderately conserved and there is a moderate physicochemical difference between leucine and glutamine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with NF1-related conditions. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. This variant disrupts the p.Leu1833 amino acid residue in NF1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1

Aug 28, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Has not been previously published as a pathogenic or benign germline variant to our knowledge; A different missense change at this residue (Leu1833Pro) has been reported in individuals with suspected or clinically diagnosed Neurofibromatosis type 1 (Xu 2014, Pasmant 2015); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; Not observed in large population cohorts (Lek 2016); This variant is associated with the following publications: (PMID: 29106415, 24789688, 25074460) -

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	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;D;.
Eigen	Pathogenic	0.88
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.95	D;D;D;D
M_CAP	Pathogenic	0.95	D
MetaRNN	Pathogenic	0.95	D;D;D;D
MetaSVM	Uncertain	0.34	D
MutationAssessor	Pathogenic	3.2	M;.;.;.
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-5.2	D;D;D;.
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D;D;D;.
Sift4G	Pathogenic	0.0	D;D;D;.
Polyphen		1.0	D;D;.;.
Vest4		0.97
MutPred		0.78		Gain of sheet (P = 0.0344);.;.;.;
MVP		0.96
MPC		2.4
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.76
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: rs878853903; hg19: chr17-29654809;