chr17-31221885-T-A

Position:

• chr17-31221885-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 5P and 4B. PM1 PM2 PP2 BP4_Strong

The NM_001042492.3(NF1):​c.1677T>A​(p.Asp559Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D559N) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.14

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.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.030688375).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.1677T>A	p.Asp559Glu	missense_variant	15/58	ENST00000358273.9
NF1	NM_000267.3	c.1677T>A	p.Asp559Glu	missense_variant	15/57
NF1	NM_001128147.3	c.1677T>A	p.Asp559Glu	missense_variant	15/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.1677T>A	p.Asp559Glu	missense_variant	15/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Mar 08, 2022

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. 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 not expected to disrupt NF1 protein function. ClinVar contains an entry for this variant (Variation ID: 999457). This variant has not been reported in the literature in individuals affected with NF1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces aspartic acid, which is acidic and polar, with glutamic acid, which is acidic and polar, at codon 559 of the NF1 protein (p.Asp559Glu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.25
BayesDel_addAF	Benign	-0.21	T
BayesDel_noAF	Benign	-0.53
CADD	Benign	12
DANN	Benign	0.46
DEOGEN2	Benign	0.39	T;.;.;T
Eigen	Benign	-0.97
Eigen_PC	Benign	-0.68
FATHMM_MKL	Uncertain	0.84	D
LIST_S2	Uncertain	0.87	D;D;D;D
M_CAP	Benign	0.046	D
MetaRNN	Benign	0.031	T;T;T;T
MetaSVM	Benign	-0.99	T
MutationAssessor	Benign	-2.2	N;N;N;.
MutationTaster	Benign	0.93	D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	0.83	N;N;N;N
REVEL	Benign	0.078
Sift	Benign	1.0	T;T;T;T
Sift4G	Benign	1.0	T;T;T;T
Polyphen		0.0	B;B;.;.
Vest4		0.14
MutPred		0.36		Gain of catalytic residue at W561 (P = 0.0419);Gain of catalytic residue at W561 (P = 0.0419);Gain of catalytic residue at W561 (P = 0.0419);.;
MVP		0.31
MPC		0.64
ClinPred		0.079	T
GERP RS		2.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.095
gMVP		0.080

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: rs1209447028; hg19: chr17-29548903;