17-31248997-G-C

Position:

• chr17-31248997-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_001042492.3(NF1):​c.3988G>C​(p.Glu1330Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,178 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.48

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 6 ACMG points.

• PM1: In a domain Ras-GAP (size 216) in uniprot entity NF1_HUMAN there are 42 pathogenic changes around while only 3 benign (93%) 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.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.766

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3988G>C	p.Glu1330Gln	missense_variant	30/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3988G>C	p.Glu1330Gln	missense_variant	30/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3988G>C	p.Glu1330Gln	missense_variant	30/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152178 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74352

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

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

Apr 19, 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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with NF1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with glutamine at codon 1330 of the NF1 protein (p.Glu1330Gln). The glutamic acid residue is moderately conserved and there is a small physicochemical difference between glutamic acid and glutamine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.74	D;.;D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.88
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.94	D;D;D
M_CAP	Pathogenic	0.64	D
MetaRNN	Pathogenic	0.77	D;D;D
MetaSVM	Uncertain	0.40	D
MutationAssessor	Benign	1.7	L;L;.
PrimateAI	Uncertain	0.58	T
PROVEAN	Benign	-2.1	N;N;N
REVEL	Uncertain	0.62
Sift	Uncertain	0.016	D;D;D
Sift4G	Uncertain	0.029	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.77
MutPred		0.42		Loss of phosphorylation at S1329 (P = 0.123);Loss of phosphorylation at S1329 (P = 0.123);.;
MVP		0.86
MPC		1.7
ClinPred		0.88	D
GERP RS		5.7
Varity_R		0.64
gMVP		0.52

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: rs1483311407; hg19: chr17-29576015; COSMIC: COSV100648456;