rs1555617362

chr17-31249083-CC-AA

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM1 PP2

The NM_001042492.3(NF1):c.4074_4075delinsAA(p.Pro1359Thr) variant causes a missense change. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. P1358P) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 4.52

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.

• PM1: In a domain Ras-GAP (size 216) in uniprot entity NF1_HUMAN there are 121 pathogenic changes around while only 10 benign (92%) in NM_001042492.3
• 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.4074_4075delinsAA	p.Pro1359Thr	missense_variant	30/58	ENST00000358273.9
NF1	NM_000267.3	c.4074_4075delinsAA	p.Pro1359Thr	missense_variant	30/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.4074_4075delinsAA	p.Pro1359Thr	missense_variant	30/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

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	Jan 16, 2024	This sequence change replaces proline, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1359 of the NF1 protein (p.Pro1359Thr). Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. 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: 457678). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

Apr 24, 2021

DNA sequence analysis of the NF1 gene demonstrated an insertion/deletion event, c.4074_4075delinsAA, in exon 30 that results in an amino acid change, p.Pro1359Thr. This sequence change does not appear to have been previously described in patients with NF1-related disorders. This sequence change has been described in one individual in the gnomAD population database. The p.Pro1359Thr change affects a moderately conserved amino acid residue of the NF1 protein. In-silico pathogenicity prediction tools (SIFT, PolyPhen2, Align GVGD, REVEL) provide contradictory results for the p.Pro1359Thr substitution. Due to the lack of functional studies, the clinical significance of the p.Pro1359Thr change remains unknown at this time. -

Juvenile myelomonocytic leukemia Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Genetics and Molecular Pathology, SA Pathology

Feb 24, 2023

The NF1 c.4074_4075delCCinsAA variant is classified as VUS (PM2) The NF1 c.4074_4075delCCinsAA variant is located in exon 30/57 of the NF1 gene, which is predicted to change the amino acid proline at position 1359 in the protein to threonine. This variant is absent from population databases (PM2). Computational predictions provide conflicting interpretations of pathogenicity for this variant (PP3 and BP4 not met). The variant has been reported in dbSNP (rs1555617362) and has been reported as Uncertain significance by other diagnostic laboratories (ClinVar Variation ID: 457678). It has not been reported in HGMD. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Feb 28, 2016

The c.4074_4075delCCinsAA variant (p.P1359T), located in coding exon 30 of the NF1 gene, results from a deletion of CC and insertion of AA at nucleotide positions 4074 and 4075. This results in the substitution of a threonine residue for proline at codon 1359. 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 110000alleles tested) in our clinical cohort.This amino acid position is well conserved in available vertebrate species. Since supporting evidence is limited at this time, the clinical significance of this alterationremains unclear. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1555617362; hg19: chr17-29576101;