chr17-31159097-A-T

Variant names:

• chr17-31159097-A-T
• NM_001042492.3:c.288+4A>T

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001042492.3(NF1):​c.288+4A>T variant causes a splice region, intron change. The variant allele was found at a frequency of 0.000000697 in 1,434,128 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 7.0e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 splice_region, intron
• Scores: Splicing: ADA: 0.5499
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 4.70

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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.33).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.288+4A>T		splice_region_variant, intron_variant	Intron 3 of 57	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.288+4A>T		splice_region_variant, intron_variant	Intron 3 of 56		NP_000258.1
NF1	NM_001128147.3	c.288+4A>T		splice_region_variant, intron_variant	Intron 3 of 14		NP_001121619.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.288+4A>T		splice_region_variant, intron_variant	Intron 3 of 57	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.97e-7 AC: 1 AN: 1434128 Hom.: 0 Cov.: 26 AF XY: 0.00 AC XY: 0 AN XY: 715236

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

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: 9.20e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Sep 15, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change falls in intron 3 of the NF1 gene. It does not directly change the encoded amino acid sequence of the NF1 protein. It affects a nucleotide within the consensus splice site. 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: 1699115). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the c.288+4A nucleotide in the NF1 gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 31370276; internal data). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. 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. -

Sep 02, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3A. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with neurofibromatosis, type 1 (MIM#162200). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0115 - Variants in this gene are known to have variable expressivity (PMID: 20301288). (I) 0212 - Non-canonical splice site variant without proven consequence on splicing (no functional evidence available). (SP) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0311 - An alternative nucleotide change at the same position is present in gnomAD (v2) (1 heterozygote, 0 homozygotes). (I) 0508 - In silico predictions for abnormal splicing are conflicting. (I) 0704 - Another splice site variant comparable to the one identified in this case has limited previous evidence for pathogenicity. c.288+4A>G has been classified as likely pathogenic, pathogenic and as a VUS by clinical laboratories in ClinVar. This alternative change has also been observed in one individual with an NF1-related condition in the literature (PMID: 31370276). (SP) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.33
CADD	Benign	18
DANN	Benign	0.95

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.55
dbscSNV1_RF	Benign	0.26
SpliceAI score (max)		0.67		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.67		Position offset: -4

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-29486115;