17-31201108-C-G

Position:

• chr17-31201108-C-G

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The ENST00000358273.9(NF1):​c.1134C>G​(p.Asp378Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,792 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. D378D) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NF1 ENST00000358273.9 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.17

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 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in ENST00000358273.9
• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.1134C>G	p.Asp378Glu	missense_variant	10/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.1134C>G	p.Asp378Glu	missense_variant	10/57		NP_000258.1
NF1	NM_001128147.3	c.1134C>G	p.Asp378Glu	missense_variant	10/15		NP_001121619.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.1134C>G	p.Asp378Glu	missense_variant	10/58	1	NM_001042492.3	ENSP00000351015	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461792 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727196

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

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

Jul 06, 2021

This sequence change replaces aspartic acid with glutamic acid at codon 378 of the NF1 protein (p.Asp378Glu). The aspartic acid residue is highly conserved and there is a small physicochemical difference between aspartic acid and glutamic acid. 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. 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: "Tolerated"; 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.25
CADD	Benign	22
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.81	.;D;.;.;T
Eigen	Benign	-0.0075
Eigen_PC	Benign	-0.036
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.91	D;D;D;D;D
M_CAP	Pathogenic	0.38	D
MetaRNN	Uncertain	0.67	D;D;D;D;D
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	1.6	L;L;L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.8	.;D;D;D;D
REVEL	Uncertain	0.63
Sift	Benign	0.084	.;T;T;T;T
Sift4G	Benign	0.089	.;T;T;D;T
Polyphen		1.0	D;D;D;.;.
Vest4		0.94, 0.95, 0.95
MutPred		0.59		Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);Gain of relative solvent accessibility (P = 0.1259);.;
MVP		0.94
MPC		1.6
ClinPred		0.98	D
GERP RS		0.83
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.31
gMVP		0.83

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: rs781367679; hg19: chr17-29528126;