rs1555608659

Positions:

• chr17-31181449-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001042492.3(NF1):​c.614A>G​(p.Lys205Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,220 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. K205E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 8.20

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
• 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.614A>G	p.Lys205Arg	missense_variant	6/58	ENST00000358273.9
NF1	NM_000267.3	c.614A>G	p.Lys205Arg	missense_variant	6/57
NF1	NM_001128147.3	c.614A>G	p.Lys205Arg	missense_variant	6/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.614A>G	p.Lys205Arg	missense_variant	6/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461220 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 726900

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 05, 2023	This sequence change replaces lysine, which is basic and polar, with arginine, which is basic and polar, at codon 205 of the NF1 protein (p.Lys205Arg). This variant is not present in population databases (gnomAD no frequency). 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: 480207). 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) performed at Invitae indicates that this missense variant is expected to disrupt 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	- -

Juvenile myelomonocytic leukemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

May 26, 2023

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 23, 2022

Not observed at significant frequency in large population cohorts (gnomAD); 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 -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Dec 06, 2023

The p.K205R variant (also known as c.614A>G), located in coding exon 6 of the NF1 gene, results from an A to G substitution at nucleotide position 614. The lysine at codon 205 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.10
CADD	Benign	22
DANN	Uncertain	1.0
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.52
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;D;D;D;D
M_CAP	Pathogenic	0.75	D
MetaRNN	Uncertain	0.66	D;D;D;D;D
MetaSVM	Uncertain	0.31	D
MutationAssessor	Benign	1.7	L;L;L;L;.
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.75	T
Polyphen		1.0	D;B;B;.;.
Vest4		0.78, 0.78, 0.83
MutPred		0.32		Loss of methylation at K205 (P = 0.0548);Loss of methylation at K205 (P = 0.0548);Loss of methylation at K205 (P = 0.0548);Loss of methylation at K205 (P = 0.0548);.;
MVP		0.85
MPC		1.5
ClinPred		0.90	D
GERP RS		5.4
Varity_R		0.25
gMVP		0.59

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: rs1555608659; hg19: chr17-29508467;