17-31265335-C-T
Variant summary
Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM1PP2PP3_ModerateBS2_Supporting
The NM_001042492.3(NF1):c.4831C>T(p.Arg1611Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000413 in 1,453,770 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
Consequence
NM_001042492.3 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes Cov.: 32
GnomAD3 exomes AF: 0.00000399 AC: 1AN: 250500Hom.: 0 AF XY: 0.00000737 AC XY: 1AN XY: 135686
GnomAD4 exome AF: 0.00000413 AC: 6AN: 1453770Hom.: 0 Cov.: 28 AF XY: 0.00000276 AC XY: 2AN XY: 723852
GnomAD4 genome Cov.: 32
ClinVar
Submissions by phenotype
Neurofibromatosis, type 1 Pathogenic:2Uncertain:1Other:1
Variant interpreted as Uncertain significance and reported on 02-10-2021 by Lab or GTR ID 26957. GenomeConnect assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. GenomeConnect staff make no attempt to reinterpret the clinical significance of the variant. -
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Variant summary: NF1 c.4768C>T (p.Arg1590Trp) results in a non-conservative amino acid change located in the CRAL-TRIO lipid binding domain (IPR001251) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 250500 control chromosomes. c.4768C>T has been reported in the heterozygous state in the literature and internally in multiple individuals affected with Neurofibromatosis Type 1, NF1-Noonan spectrum conditions, isolated cafe au lait macules or breast cancer (Upadhyaya_1997,Giugliano_2019,Dorling_2021, Stella_2018, Bianchessi_2020, Evans_2016, Labcorp Genetics (formerly Invitae)). It has also been reported in control cohorts and clinically unaffected family members (Okawa_2023, Dorling_2021, Evans_2016, Bianchessi_2020), suggesting incomplete penetrance or variable expressivity. These data indicate that the variant is very likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in about 20% of NF1 expression in E. coli (Welti_2010). Additionally, one missense variant at the Arg1590 residue has been reported in ClinVar (NM_000267.3:c.4769G>T p.Arg1590Leu), suggesting that this codon might be functionally important. The following publications have been ascertained in the context of this evaluation (PMID: 33471991, 31370276, 36243179, 9298829, 21089070, 29673180, 32575496, 27322474). ClinVar contains an entry for this variant (Variation ID: 404515). Based on the evidence outlined above, the variant was classified as pathogenic. -
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 1590 of the NF1 protein (p.Arg1590Trp). This variant is present in population databases (no rsID available, gnomAD 0.006%). This missense change has been observed in individual(s) with clinical features of neurofibromatosis type 1 (PMID: 9298829, 27322474, 29673180, 32575496). ClinVar contains an entry for this variant (Variation ID: 404515). 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%. Experimental studies have shown that this missense change affects NF1 function (PMID: 21089070). This variant disrupts the p.Arg1590 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. -
not provided Uncertain:4
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Observed in individuals with features of neurofibromatosis type 1, several of whom did not meet NIH criteria (PMID: 9298829, 27322474, 29471550, 29673180, 31370276, 32575496); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Observed in clinically unaffected adult relatives of individuals with features of neurofibromatosis type 1 referred for genetic testing at GeneDx and in published literature (PMID: 32575496, 27322474); This variant is associated with the following publications: (PMID: 32680567, 21089070, 9298829, 24803665, 27322474, 16405917, 29471550, 31370276, 32575496, 29673180, 35885913, 36243179) -
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NF1-related disorder Uncertain:1
The NF1 c.4831C>T variant is predicted to result in the amino acid substitution p.Arg1611Trp. This variant is also referred to as p.Arg1590Trp in an alternate transcript (NM_000267.3). This variant has been reported in individuals with features of neurofibromatosis type 1 (Upadhyaya et al. 1997. PubMed ID: 9298829; Giugliano et al. 2019. PubMed ID: 31370276; Stella A et al. 2018. PubMed ID: 29673180). However, the variant was also detected in unaffected family members (Evans et al. 2016. PubMed ID: 27322474; Bianchessi et al. 2020. PubMed ID: 32575496). This variant is reported in 0.0054% of alleles in individuals of East Asian descent in gnomAD and has conflicting interpretations of likely pathogenic and uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/404515/). Although we suspect this variant could be pathogenic, at this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -
Juvenile myelomonocytic leukemia Uncertain:1
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Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Uncertain:1
The p.R1590W variant (also known as c.4768C>T), located in coding exon 35 of the NF1 gene, results from a C to T substitution at nucleotide position 4768. The arginine at codon 1590 is replaced by tryptophan, an amino acid with dissimilar properties. This variant was reported in multiple individuals with features consistent with neurofibromatosis type 1 (Upadhyaya M et al. Hum Mutat, 1997;10:248-50; Barrea C et al. Neuropediatrics, 2018 Jun;49:180-184; Napolitano F et al. Genes (Basel), 2022 Jun;13:). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at