17-31258376-C-G

Position:

• chr17-31258376-C-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_001042492.3(NF1):​c.4206C>G​(p.Ile1402Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. I1402?) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.182

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]

NF1 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM1: In a helix (size 10) in uniprot entity NF1_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) 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 chr17-31258373-CAT-CG is described in Lovd as [Pathogenic].
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4206C>G	p.Ile1402Met	missense_variant	32/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.4143C>G	p.Ile1381Met	missense_variant	31/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4206C>G	p.Ile1402Met	missense_variant	32/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 19, 2019

The p.I1381M variant (also known as c.4143C>G), located in coding exon 31 of the NF1 gene, results from a C to G substitution at nucleotide position 4143. The isoleucine at codon 1381 is replaced by methionine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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	0.23
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.070
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D;.;D
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.27
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Uncertain	0.72	D;D;D
MetaSVM	Uncertain	0.15	D
MutationAssessor	Uncertain	2.1	M;.;.
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-1.7	N;N;N
REVEL	Pathogenic	0.65
Sift	Uncertain	0.0040	D;D;D
Sift4G	Uncertain	0.018	D;D;D
Polyphen		0.96	D;D;.
Vest4		0.83
MutPred		0.69		Gain of disorder (P = 0.0346);.;.;
MVP		0.86
MPC		1.6
ClinPred		0.91	D
GERP RS		3.7
Varity_R		0.87
gMVP		0.44

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs864622406; hg19: chr17-29585394;