17-31226465-C-T

Position:

• chr17-31226465-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM2 PM5 PP2 BP4_Moderate

The NM_001042492.3(NF1):​c.2032C>T​(p.Pro678Ser) variant causes a missense change. The variant allele was found at a frequency of 0.00000274 in 1,461,532 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 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 same amino acid change has been previously reported as Uncertain significancein ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P678A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:1
• Conservation: PhyloP100: 5.72

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-31226466-CG-A is described in ClinVar as [Pathogenic]. Clinvar id is 1203954.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant where missense usually causes diseases, NF1
• BP4: Computational evidence support a benign effect (MetaRNN=0.13330102).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.2032C>T	p.Pro678Ser	missense_variant	18/58	ENST00000358273.9
NF1	NM_000267.3	c.2032C>T	p.Pro678Ser	missense_variant	18/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.2032C>T	p.Pro678Ser	missense_variant	18/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000399 AC: 10 AN: 250606 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135426

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000544

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461532 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727078

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

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

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Dec 24, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 02, 2016

The c.2032C>T (p.P678S) alteration is located in exon 18 (coding exon 18) of the NF1 gene. This alteration results from a C to T substitution at nucleotide position 2032, causing the proline (P) at amino acid position 678 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jul 16, 2014

The p.P678S variant (also known as c.2032C>T), located in coding exon 18 of the NF1 gene, results from a C to T substitution at nucleotide position 2032. The proline at codon 678 is replaced by serine, an amino acid with similar 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 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.01% (greater than 11000 alleles tested) in our clinical cohort (includes this individual). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be benign and tolerated by PolyPhen and SIFT in silico analyses, respectively. Since supporting evidence is limited at this time, the clinical significance of p.P678S remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.13
BayesDel_addAF	Benign	-0.36	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	21
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.53	D;.;T
Eigen	Benign	0.0051
Eigen_PC	Benign	0.15
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Benign	0.058	D
MetaRNN	Benign	0.13	T;T;T
MetaSVM	Benign	-1.0	T
MutationAssessor	Benign	1.3	L;L;.
MutationTaster	Benign	0.98	D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Benign	-1.5	N;N;N
REVEL	Benign	0.11
Sift	Uncertain	0.024	D;D;D
Sift4G	Benign	0.11	T;T;T
Polyphen		0.015	B;B;.
Vest4		0.25
MutPred		0.26		Loss of catalytic residue at P677 (P = 0.0135);Loss of catalytic residue at P677 (P = 0.0135);.;
MVP		0.37
MPC		0.73
ClinPred		0.12	T
GERP RS		4.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.15
gMVP		0.52

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: rs758691069; hg19: chr17-29553483;