17-31258405-G-C

Variant names:

• chr17-31258405-G-C
• rs1555618516
• NM_001042492.3:c.4235G>C

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5

The NM_001042492.3(NF1):​c.4235G>C​(p.Arg1412Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,461,710 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R1412G) has been classified as Pathogenic.

• 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 P:4 U:2
• Conservation: PhyloP100: 9.56

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 Pathogenic. Variant got 12 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
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-31258404-A-G is described in Lovd as [Pathogenic].
• 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, 0.989
• PP5: Variant 17-31258405-G-C is Pathogenic according to our data. Variant chr17-31258405-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 523345.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=2, Pathogenic=2}. Variant chr17-31258405-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4235G>C	p.Arg1412Thr	missense_variant	Exon 32 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.4172G>C	p.Arg1391Thr	missense_variant	Exon 31 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4235G>C	p.Arg1412Thr	missense_variant	Exon 32 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461710 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727154

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: Pathogenic:4 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:1 Uncertain:2

Jan 06, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with threonine, which is neutral and polar, at codon 1391 of the NF1 protein (p.Arg1391Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with NF1- Noonan syndrome and neurofibormatosis type 1 (NF1) (PMID: 24789688, 27322474; internal data). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 523345). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt NF1 protein function with a positive predictive value of 95%. This variant disrupts the p.Arg1391 amino acid residue in NF1. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 7581973, 9003501, 16513807, 22807134, 27322474). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Oct 26, 2020

Genome Diagnostics Laboratory, The Hospital for Sick Children

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 01, 2016

Center for Human Genetics, Inc, Center for Human Genetics, Inc

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Neurofibroma;C1861975:Cafe au lait spots, multiple;C4025846:Abnormality of vision Pathogenic:1

Jan 01, 2017

Centre for Mendelian Genomics, University Medical Centre Ljubljana

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Mar 19, 2024

Mayo Clinic Laboratories, Mayo Clinic

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP3, PP4, PM2_moderate, PS4_moderate -

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

Sep 03, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R1391T pathogenic mutation (also known as c.4172G>C), located in coding exon 31 of the NF1 gene, results from a G to C substitution at nucleotide position 4172. The arginine at codon 1391 is replaced by threonine, an amino acid with similar properties. This variant was reported in multiple individuals who met clinical criteria for Neurofibromatosis type1 or were suspected of having Neurofibromatosis type 1 (van Minkelen R et al. Clin Genet, 2014 Apr;85:318-27; Xu W et al. Int J Mol Med, 2014 Jul;34:53-60; Evans DG et al. EBioMedicine, 2016 May;7:212-20). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Another variant at the same codon, p.R1391S (c.4173A>T), has been detected in individuals with Neurofibromatosis type 1 (Upadhyaya M et al. Hum. Genet., 1997 Jan;99:88-92; Evans DG et al. EBioMedicine, 2016 May;7:212-20). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	29
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.95	D;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D;D
M_CAP	Pathogenic	0.97	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.8	H;.;.
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-4.8	D;D;D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D;D;D
Sift4G	Uncertain	0.0020	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.98
MutPred		0.94		Loss of MoRF binding (P = 0.0755);.;.;
MVP		0.99
MPC		1.4
ClinPred		0.98	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.96

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: rs1555618516; hg19: chr17-29585423;