rs1060500259

chr17-31229184-A-Cchr17-31229184-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001042492.3(NF1):c.2569A>C(p.Asn857His) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign 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. N857S) has been classified 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:2
• Conservation: PhyloP100: 7.11

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 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1
• BP4: Computational evidence support a benign effect (MetaRNN=0.20381731).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.2569A>C	p.Asn857His	missense_variant	21/58	ENST00000358273.9
NF1	NM_000267.3	c.2569A>C	p.Asn857His	missense_variant	21/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.2569A>C	p.Asn857His	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:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

May 27, 2020

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with NF1-related conditions. ClinVar contains an entry for this variant (Variation ID: 404439). This variant is not present in population databases (ExAC no frequency). This sequence change replaces asparagine with histidine at codon 857 of the NF1 protein (p.Asn857His). The asparagine residue is weakly conserved and there is a small physicochemical difference between asparagine and histidine. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 16, 2020

The p.N857H variant (also known as c.2569A>C), located in coding exon 21 of the NF1 gene, results from an A to C substitution at nucleotide position 2569. The asparagine at codon 857 is replaced by histidine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.24	T
BayesDel_noAF	Benign	-0.58
Cadd	Benign	22
Dann	Uncertain	0.98
DEOGEN2	Uncertain	0.60	D;.;T
Eigen	Benign	0.072
Eigen_PC	Uncertain	0.27
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Benign	0.047	D
MetaRNN	Benign	0.20	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	0.69	N;N;.
MutationTaster	Benign	0.94	D;D
PrimateAI	Benign	0.43	T
PROVEAN	Benign	-1.9	N;N;N
REVEL	Benign	0.097
Sift	Uncertain	0.020	D;D;D
Sift4G	Benign	0.11	T;T;T
Polyphen		0.040	B;B;.
Vest4		0.23
MutPred		0.29		Loss of solvent accessibility (P = 0.0155);Loss of solvent accessibility (P = 0.0155);.;
MVP		0.55
MPC		0.77
ClinPred		0.45	T
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.17
gMVP		0.18

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: rs1060500259; hg19: chr17-29556202;