chr17-31232852-A-G

Variant names:

• chr17-31232852-A-G
• rs199474764
• NM_001042492.3:c.3467A>G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP2 PP3_Moderate PP5

The NM_001042492.3(NF1):​c.3467A>G​(p.Asn1156Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. N1156N) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6 U:3 O:1
• Conservation: PhyloP100: 8.88

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 Likely_pathogenic. Variant got 6 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, 0.85
• PP5: Variant 17-31232852-A-G is Pathogenic according to our data. Variant chr17-31232852-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 68332.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=1, Uncertain_significance=3, Pathogenic=4, not_provided=1}. Variant chr17-31232852-A-G is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3467A>G	p.Asn1156Ser	missense_variant	Exon 26 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3467A>G	p.Asn1156Ser	missense_variant	Exon 26 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3467A>G	p.Asn1156Ser	missense_variant	Exon 26 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251354 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135840

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1461854 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727230

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.: 31

Bravo AF: 0.00000378

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000116 AC: 1

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:6 Uncertain:3 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:3

Oct 16, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine, which is neutral and polar, with serine, which is neutral and polar, at codon 1156 of the NF1 protein (p.Asn1156Ser). This variant is present in population databases (rs199474764, gnomAD 0.0009%). This missense change has been observed in individual(s) with clinical features consistent with neurofibromatosis, type 1 (PMID: 10712197, 24789688; internal data). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 68332). 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.Asn1156 amino acid residue in NF1. Other variant(s) that disrupt this residue have been determined to be pathogenic (internal data). 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. -

Mar 04, 2025

Institute of Human Genetics, University of Leipzig Medical Center

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Criteria applied: PVS1(RNA),PS4_MOD,PM2 -

Jan 21, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: NF1 c.3467A>G (p.Asn1156Ser) results in a conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. Several computational tools predict a significant impact on normal splicing: One predict the variant abolishes a cryptic exonic 3' acceptor site. Two predict the variant creates an alternate cryptic exonic 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 251354 control chromosomes. c.3467A>G has been reported in the literature in individuals affected with Neurofibromatosis Type 1 (e.g. Xu_2014, Fahsold_2020), although a congruence to NF1 pseudogene sequence was reported in at-least one of these reports (Fahsold_2020). Additionally, this variant has been observed in multiple cases with clinical features of Neurofibromatosis, Type 1 tested at our laboratory and data shared by the NF1 VCEP group, University of Alabama (personal correspondence). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 10712197, 31617914, 24789688). ClinVar contains an entry for this variant (Variation ID: 68332). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1 Uncertain:1 Other:1

Jul 18, 2024

GeneDx

Significance: Pathogenic

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; This variant is associated with the following publications: (PMID: 31617914, 24789688, 24803665, 25074460, 10712197, 34449562, 25486365, 2121369, 22807134) -

Jan 26, 2022

Institute of Human Genetics, Clinical Exome/Genome Diagnostics Group, University Hospital Bonn

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PP2, PP5, PS4 -

-

UniProtKB/Swiss-Prot

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Neurofibromatosis, type 1;C0349639:Juvenile myelomonocytic leukemia;C0553586:Café-au-lait macules with pulmonary stenosis;C1834235:Neurofibromatosis, familial spinal;C2931482:Neurofibromatosis-Noonan syndrome Pathogenic:1

-

Juno Genomics, Hangzhou Juno Genomics, Inc

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

PM2_Supporting+PP2+PS4_Moderate+PP4+PM6_Supporting -

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

Nov 15, 2024

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.N1156S variant (also known as c.3467A>G), located in coding exon 26 of the NF1 gene, results from an A to G substitution at nucleotide position 3467. The asparagine at codon 1156 is replaced by serine, an amino acid with highly similar properties. This alteration has been identified in multiple individuals with a clinical diagnosis of neurofibromatosis type 1 (NF1) and has been identified de novo in several cases (Xu W et al. Int J Mol Med, 2014 Jul;34:53-60; Fahsold R et al. Am. J. Hum. Genet. 2000; 66:790-818; Togi S et al. Curr Issues Mol Biol, 2021 Jul;43:782-801; external communication). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the supporting evidence, this variant is interpreted as a disease-causing mutation. -

not specified Uncertain:1

May 22, 2019

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The NF1 c.3467A>G; p.Asn1156Ser variant (rs199474764) has been described in individuals affected with neurofibromatosis type 1 (NF1; Fahsold 2000, Xu 2014). It is observed on only one allele in the Genome Aggregation Database, indicating it is not a common polymorphism. The asparagine at codon 1156 is highly conserved, and computational algorithms (PolyPhen-2, SIFT) predict that this variant is deleterious. Additionally, computational splicing programs (Alamut v.2.11) predict that this variant impacts splicing by creating a cryptic splice acceptor site, and analysis of mRNA from peripheral blood of an individual harboring this variant demonstrated aberrant splicing leading to exon skipping (Xu 2014). However, this study did not quantify the amount of incorrectly spliced transcript. Due to limited information regarding this variant, its clinical significance cannot be determined with certainty. REFERNECES Fahsold R et al. Minor lesion mutational spectrum of the entire NF1 gene does not explain its high mutability but points to a functional domain upstream of the GAP-related domain. Am J Hum Genet. 2000 Mar;66(3):790-818. Xu W et al. Fifty-four novel mutations in the NF1 gene and integrated analyses of the mutations that modulate splicing. Int J Mol Med. 2014 Jul;34(1):53-60. -

Juvenile myelomonocytic leukemia Uncertain:1

Oct 24, 2023

Baylor Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.90
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Benign	-0.21
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Pathogenic	0.88	D
MetaRNN	Pathogenic	0.85	D;D;D
MetaSVM	Benign	-0.47	T
MutationAssessor	Pathogenic	3.3	M;M;.
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-4.0	D;D;D
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0	D;D;D
Polyphen		1.0	D;D;.
Vest4		0.95
MVP		0.81
MPC		1.5
ClinPred		0.99	D
GERP RS		5.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.61
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs199474764; hg19: chr17-29559870;