chr17-31327653-C-A

Position:

• chr17-31327653-C-A

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_001042492.3(NF1):​c.5423C>A​(p.Thr1808Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.54

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 5 ACMG points.

• PM1: In a region_of_interest Lipid binding (size 257) in uniprot entity NF1_HUMAN there are 37 pathogenic changes around while only 10 benign (79%) in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), NF1. . Gene score misZ 6.5427 (greater than the threshold 3.09). Trascript score misZ 8.4054 (greater than threshold 3.09). GenCC has associacion of gene with neurofibromatosis, familial spinal, hereditary pheochromocytoma-paraganglioma, neurofibromatosis type 1, Watson syndrome, neurofibromatosis-Noonan syndrome, Moyamoya disease, familial ovarian cancer.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.5423C>A	p.Thr1808Lys	missense_variant	38/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.5360C>A	p.Thr1787Lys	missense_variant	37/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.5423C>A	p.Thr1808Lys	missense_variant	38/58	1	NM_001042492.3	ENSP00000351015	P1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 20, 2016

The p.T1787K variant (also known as c.5360C>A), located in coding exon 37 of the NF1 gene, results from a C to A substitution at nucleotide position 5360. The threonine at codon 1787 is replaced by lysine, 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 0.001% (greater than 175000 alleles tested) in our clinical cohort. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. 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	Pathogenic	0.59
BayesDel_addAF	Pathogenic	0.37	D
BayesDel_noAF	Pathogenic	0.29
CADD	Uncertain	25
DANN	Benign	0.94
DEOGEN2	Uncertain	0.58	D;.;T
Eigen	Benign	0.084
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.91	D;D;D
M_CAP	Pathogenic	0.61	D
MetaRNN	Uncertain	0.67	D;D;D
MetaSVM	Benign	-0.36	T
MutationAssessor	Benign	1.1	L;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Benign	-2.1	N;N;N
REVEL	Uncertain	0.51
Sift	Benign	0.89	T;T;T
Sift4G	Uncertain	0.042	D;D;D
Polyphen		0.0090	B;D;.
Vest4		0.90
MutPred		0.43		Gain of ubiquitination at T1808 (P = 0.0247);.;.;
MVP		0.91
MPC		2.5
ClinPred		0.96	D
GERP RS		6.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.50
gMVP		0.84

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: rs760649828; hg19: chr17-29654671;