17-31260474-G-C

Variant names:

• chr17-31260474-G-C
• rs878853897
• NM_001042492.3:c.4536G>C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_001042492.3(NF1):​c.4536G>C​(p.Trp1512Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,700 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4 B:1
• Conservation: PhyloP100: 9.25

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.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the NF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 399 curated pathogenic missense variants (we use a threshold of 10). The gene has 143 curated benign missense variants. Gene score misZ: 6.5427 (above the threshold of 3.09). Trascript score misZ: 8.4054 (above the threshold of 3.09). GenCC associations: The gene is linked to 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, 0.916

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4536G>C	p.Trp1512Cys	missense_variant	Exon 34 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.4473G>C	p.Trp1491Cys	missense_variant	Exon 33 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4536G>C	p.Trp1512Cys	missense_variant	Exon 34 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461700 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727152

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:4 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1 Benign:1

Mar 15, 2022

Genome-Nilou Lab

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Juvenile myelomonocytic leukemia Uncertain:1

Aug 13, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Uncertain:1

Feb 21, 2023

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 29617658, 22807134) -

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

Jul 18, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.W1491C variant (also known as c.4473G>C), located in coding exon 33 of the NF1 gene, results from a G to C substitution at nucleotide position 4473. The tryptophan at codon 1491 is replaced by cysteine, an amino acid with highly dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious 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	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.89	D;.;T
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D;D;D
M_CAP	Pathogenic	0.68	D
MetaRNN	Pathogenic	0.92	D;D;D
MetaSVM	Uncertain	0.30	D
MutationAssessor	Uncertain	2.1	M;.;.
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-11	D;D;D
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0010	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.93
MutPred		0.56		Loss of ubiquitination at K1517 (P = 0.063);.;.;
MVP		0.98
MPC		2.2
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.92
gMVP		0.91

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: rs878853897; hg19: chr17-29587492;