17-31230373-T-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5

The NM_001042492.3(NF1):c.3104T>C(p.Met1035Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,120 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M1035K) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:2
• Conservation: PhyloP100: 7.64

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 10 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, 14 uncertain 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 chr17-31230373-T-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 658527.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, NF1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.857
• PP5: Variant 17-31230373-T-C is Pathogenic according to our data. Variant chr17-31230373-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 431618.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=2, Uncertain_significance=2, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.3104T>C	p.Met1035Thr	missense_variant	23/58	ENST00000358273.9
NF1	NM_000267.3	c.3104T>C	p.Met1035Thr	missense_variant	23/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.3104T>C	p.Met1035Thr	missense_variant	23/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461120 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 726858

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:2 Uncertain:1

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Oct 03, 2023	This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1035 of the NF1 protein (p.Met1035Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with a clinical diagnosis or suspicion of neurofibromatosis type 1 (PMID: 24789688; Invitae). ClinVar contains an entry for this variant (Variation ID: 431618). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt NF1 protein function. This variant disrupts the p.Met1035 amino acid residue in NF1. Other variant(s) that disrupt this residue have been determined to be pathogenic (Invitae). 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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Medical Genetics, University of Parma	Aug 17, 2022	- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 02, 2023

Observed in an individual with a diagnosis or clinical suspicion of neurofibromatosis type 1 (Xu et al., 2014); 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; This variant is associated with the following publications: (PMID: Martorana2022[CaseReport], 25486365, 2121369, 24789688, 26582918, 24077912, 31370276, 34080803) -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 27, 2016

The p.M1035T variant (also known as c.3104T>C), located in coding exon 23 of the NF1 gene, results from a T to C substitution at nucleotide position 3104. The methionine at codon 1035 is replaced by threonine, an amino acid with similar properties. This variant was listed as novel in a cohort that either met clinical criteria or were suspected to have neurofibromatosis type 1; however, no specific clinical information was provided about the patient with this variant (Xu W, Int. J. Mol. Med. 2014 Jul; 34(1):53-60). This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6499 samples (12998 alleles) with coverage at this position. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on available evidence to date, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
Cadd	Uncertain	25
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D;.;T
Eigen	Uncertain	0.41
Eigen_PC	Uncertain	0.48
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.92	D;D;D
M_CAP	Pathogenic	0.78	D
MetaRNN	Pathogenic	0.86	D;D;D
MetaSVM	Benign	-1.2	T
MutationAssessor	Uncertain	2.1	M;M;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Uncertain	-3.9	D;D;D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0030	D;D;D
Sift4G	Uncertain	0.0020	D;D;D
Polyphen		0.89	P;P;.
Vest4		0.97
MutPred		0.55		Gain of methylation at K1036 (P = 0.0292);Gain of methylation at K1036 (P = 0.0292);.;
MVP		0.80
MPC		1.6
ClinPred		0.98	D
GERP RS		5.3
Varity_R		0.64
gMVP		0.68

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: rs137854553; hg19: chr17-29557391;