17-31336914-G-T

Variant names:

• chr17-31336914-G-T
• rs1555534775
• NM_001042492.3:c.6427G>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP3

The NM_001042492.3(NF1):​c.6427G>T​(p.Glu2143*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,456,442 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. E2143E) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 stop_gained, splice_region
• Scores: Splicing: ADA: 0.9996
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.37
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• neurofibromatosis type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• neurofibromatosis-Noonan syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• Moyamoya disease

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial ovarian cancer

  Inheritance: Unknown Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001042492.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	NM_001042492.3	MANE Select	c.6427G>T	p.Glu2143*	stop_gained splice_region	Exon 42 of 58	NP_001035957.1	P21359-1
	NF1	NM_000267.4		c.6364G>T	p.Glu2122*	stop_gained splice_region	Exon 41 of 57	NP_000258.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	ENST00000358273.9	TSL:1 MANE Select	c.6427G>T	p.Glu2143*	stop_gained splice_region	Exon 42 of 58	ENSP00000351015.4	P21359-1
	NF1	ENST00000356175.7	TSL:1	c.6364G>T	p.Glu2122*	stop_gained splice_region	Exon 41 of 57	ENSP00000348498.3	P21359-2
	NF1	ENST00000579081.6	TSL:1	n.*1592G>T		splice_region non_coding_transcript_exon	Exon 42 of 58	ENSP00000462408.2	J3KSB5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1456442 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 724770

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86178

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48224

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111908

Other (OTH) AF: 0.00 AC: 0 AN: 60350

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	51
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Pathogenic	0.69	D
PhyloP100		9.4
Vest4		0.98
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Mutation Taster		=0/200	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.90
SpliceAI score (max)		0.67		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.67		Position offset: 0

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

Other links and lift over

dbSNP: rs1555534775; hg19: chr17-29663932;