NM_001042492.3:c.2032C>G
Variant summary
Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_ModerateBP6BS2_Supporting
The NM_001042492.3(NF1):c.2032C>G(p.Pro678Ala) variant causes a missense change. The variant allele was found at a frequency of 0.0000118 in 1,613,608 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely benign in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P678L) has been classified as Likely benign.
Frequency
Consequence
NM_001042492.3 missense
Scores
Clinical Significance
Conservation
Publications
- neurofibromatosis type 1Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Genomics England PanelApp
 - neurofibromatosis-Noonan syndromeInheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
 - Moyamoya diseaseInheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
 - hereditary pheochromocytoma-paragangliomaInheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
 - familial ovarian cancerInheritance: AD Classification: NO_KNOWN Submitted by: ClinGen
 
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ACMG classification
Our verdict: Likely_benign. The variant received -4 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes   AF:  0.0000329  AC: 5AN: 152076Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000120  AC: 3AN: 250606 AF XY:  0.0000148   show subpopulations 
GnomAD4 exome  AF:  0.00000958  AC: 14AN: 1461532Hom.:  0  Cov.: 34 AF XY:  0.0000124  AC XY: 9AN XY: 727078 show subpopulations 
Age Distribution
GnomAD4 genome   AF:  0.0000329  AC: 5AN: 152076Hom.:  0  Cov.: 32 AF XY:  0.0000269  AC XY: 2AN XY: 74282 show subpopulations 
ClinVar
Submissions by phenotype
Neurofibromatosis, type 1    Uncertain:2Benign:1 
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The NF1 c.2032C>G (p.Pro678Ala) change has a maximum subpopulation frequency of 0.020% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with Neurofibromatosis type 1. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -
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Hereditary cancer-predisposing syndrome    Uncertain:2 
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The p.P678A variant (also known as c.2032C>G), located in coding exon 18 of the NF1 gene, results from a C to G substitution at nucleotide position 2032. The proline at codon 678 is replaced by alanine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of p.P678A remains unclear. -
not specified    Uncertain:1 
Variant summary: NF1 c.2032C>G (p.Pro678Ala) results in a non-conservative amino acid change in the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 250606 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.2032C>G in individuals affected with Neurofibromatosis Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. Two ClinVar submitters have assessed the variant since 2014: both classified the variant as of uncertain significance. Based on the evidence outlined above, the variant was classified as uncertain significance. -
not provided    Uncertain:1 
In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 25486365) -
Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype    Benign:1 
This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at