rs9890283

Positions:

• chr17-31232900-T-C

Variant summary

Our verdict is Benign. Variant got -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BS1 BS2

The NM_001042492.3(NF1):​c.3496+19T>C variant causes a intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00118 in 1,613,898 control chromosomes in the GnomAD database, including 24 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0062 (10 hom., cov: 31)
  • Exomes 𝑓: 0.00065 (14 hom.)
• Consequence: NF1 NM_001042492.3 intron
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:7
• Conservation: PhyloP100: 1.36

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]

NF1 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.85).
• BP6: Variant 17-31232900-T-C is Benign according to our data. Variant chr17-31232900-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 257284.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31232900-T-C is described in Lovd as [Benign].
• BS1: Variant frequency is greater than expected in population afr. gnomad4 allele frequency = 0.00624 (950/152164) while in subpopulation AFR AF= 0.022 (911/41500). AF 95% confidence interval is 0.0208. There are 10 homozygotes in gnomad4. There are 438 alleles in male gnomad4 subpopulation. Median coverage is 31. This position pass quality control queck.
• BS2: High AC in GnomAd4 at 950 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3496+19T>C		intron_variant		ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3496+19T>C		intron_variant			NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3496+19T>C		intron_variant		1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.00625 AC: 950 AN: 152046 Hom.: 10 Cov.: 31

Gnomad AFR AF: 0.0220

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00151

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00622

GnomAD3 exomes AF: 0.00169 AC: 425 AN: 250870 Hom.: 2 AF XY: 0.00110 AC XY: 149 AN XY: 135606

Gnomad AFR exome AF: 0.0237

Gnomad AMR exome AF: 0.000926

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000441

Gnomad OTH exome AF: 0.000327

GnomAD4 exome AF: 0.000651 AC: 951 AN: 1461734 Hom.: 14 Cov.: 32 AF XY: 0.000518 AC XY: 377 AN XY: 727172

Gnomad4 AFR exome AF: 0.0241

Gnomad4 AMR exome AF: 0.000939

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000580

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000117

Gnomad4 OTH exome AF: 0.00137

GnomAD4 genome AF: 0.00624 AC: 950 AN: 152164 Hom.: 10 Cov.: 31 AF XY: 0.00589 AC XY: 438 AN XY: 74400

Gnomad4 AFR AF: 0.0220

Gnomad4 AMR AF: 0.00150

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00616

Alfa AF: 0.00308 Hom.: 0

Bravo AF: 0.00736

Asia WGS AF: 0.00144 AC: 5 AN: 3478

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:7

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Benign:3

Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Center for Human Genetics, Inc, Center for Human Genetics, Inc	Nov 01, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

not specified Benign:2

Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jan 06, 2020	Variant summary: NF1 c.3496+19T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. 5/5 computational tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 0.0017 in 250870 control chromosomes in the gnomAD database, including 2 homozygotes. The observed variant frequency is approximately 677.6 fold the estimated maximal expected allele frequency for a pathogenic variant in NF1 causing Noonan Syndrome and Related Conditions phenotype (2.5e-06), strongly suggesting that the variant is benign. To our knowledge, no occurrence of c.3496+19T>C in individuals affected with Noonan Syndrome and Related Conditions and no experimental evidence demonstrating an impact on protein function have been reported. Two other clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Both laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -
Benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -

not provided Benign:2

Benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Nov 06, 2023	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 02, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.85
CADD	Benign	3.7
DANN	Benign	0.53

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs9890283; hg19: chr17-29559918;