rs786203038

chr17-31156044-A-Cchr17-31156044-A-T

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_001042492.3(NF1):c.122A>C(p.Glu41Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,524 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E41V) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 8.78

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 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 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 chr17-31156044-A-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 586954.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, NF1

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.122A>C	p.Glu41Ala	missense_variant	2/58	ENST00000358273.9
NF1	NM_000267.3	c.122A>C	p.Glu41Ala	missense_variant	2/57
NF1	NM_001128147.3	c.122A>C	p.Glu41Ala	missense_variant	2/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.122A>C	p.Glu41Ala	missense_variant	2/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251180 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135756

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461524 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727074

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Dec 13, 2023	This sequence change replaces glutamic acid, which is acidic and polar, with alanine, which is neutral and non-polar, at codon 41 of the NF1 protein (p.Glu41Ala). This variant is present in population databases (rs786203038, gnomAD 0.0009%). This variant has not been reported in the literature in individuals affected with NF1-related conditions. ClinVar contains an entry for this variant (Variation ID: 186556). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on NF1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 12, 2015

The p.E41A variant (also known as c.122A>C), located in coding exon 2 of the NF1 gene, results from an A to C substitution at nucleotide position 122. The glutamic acid at codon 41 is replaced by alanine, an amino acid with dissimilar properties. 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 6502 samples (13004 alleles) with coverage at this position.<span style="background-color:initial">To date, this alteration has been detected with an allele frequency of approximately 0.01% (greater than 55000 alleles tested) in our clinical cohort.<span style="background-color:initial">This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive.<span style="background-color:initial">Since supporting evidence is limited at this time, the clinical significance of p.E41A remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.60
BayesDel_addAF	Uncertain	0.071	D
BayesDel_noAF	Benign	-0.14
Cadd	Uncertain	25
Dann	Benign	0.93
Eigen	Uncertain	0.29
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.34	D
MetaRNN	Uncertain	0.54	D;D;D;D
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.3	L;L;L;L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Pathogenic	0.81	D
Polyphen		0.97	D;B;D;.
Vest4		0.80, 0.81, 0.79
MutPred		0.22		Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);Loss of solvent accessibility (P = 0.0224);
MVP		0.81
MPC		1.7
ClinPred		0.92	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.42
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		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: rs786203038; hg19: chr17-29483062;