rs786203084

chr17-31229209-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001042492.3(NF1):c.2594C>T(p.Pro865Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• 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]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.2594C>T	p.Pro865Leu	missense_variant	21/58	ENST00000358273.9
NF1	NM_000267.3	c.2594C>T	p.Pro865Leu	missense_variant	21/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.2594C>T	p.Pro865Leu	missense_variant	21/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Mar 22, 2018	This sequence change replaces proline with leucine at codon 865 of the NF1 protein (p.Pro865Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine. 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 disease. ClinVar contains an entry for this variant (Variation ID: 186610). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 13, 2014

The p.P865L variant (also known as c.2594C>T), located in coding exon 21 of the NF1 gene, results from a C to T substitution at nucleotide position 2594. The proline at codon 865 is replaced by leucine, an amino acid with similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position.<span style="background-color: initial;">To date, this alteration has been detected with an allele frequency of approximately 0.01% (greater than 11000 alleles tested) in our clinical cohort.<span style="background-color: initial;">This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis.<span style="background-color: initial;">Since supporting evidence is limited at this time, the clinical significance of<span style="background-color: initial;">p.P865L<strong style="background-color: initial;"><span style="background-color: initial;">remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.16
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.69	D;.;T
Eigen	Benign	0.13
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D;D;D
M_CAP	Pathogenic	0.61	D
MetaRNN	Uncertain	0.57	D;D;D
MetaSVM	Uncertain	0.21	D
MutationAssessor	Benign	1.6	L;L;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Uncertain	-3.0	D;D;D
REVEL	Uncertain	0.55
Sift	Benign	0.43	T;T;T
Sift4G	Benign	0.17	T;T;T
Polyphen		0.011	B;D;.
Vest4		0.78
MutPred		0.32		Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);.;
MVP		0.85
MPC		1.7
ClinPred		0.97	D
GERP RS		5.4
Varity_R		0.32
gMVP		0.61

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs786203084; hg19: chr17-29556227;