Genetic Variant NF1:p.Ala2274Thr (chr17-31338704-G-A) – ACMG Classification: Likely_pathogenic (8 pts)

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PM5PP2PP3

The NM_001042492.3(NF1):c.6820G>A(p.Ala2274Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000687 in 1,456,598 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 predicting alterations to normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A2274S) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense, splice_region

Scores

Splicing: ADA: 0.9994

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 8.59

Variant links:

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 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 13 uncertain in NM_001042492.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr17-31338704-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 527433.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP2

Missense variant in the NF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 399 curated pathogenic missense variants (we use a threshold of 10). The gene has 143 curated benign missense variants. Gene score misZ: 6.5427 (above the threshold of 3.09). Trascript score misZ: 8.4054 (above the threshold of 3.09). GenCC associations: The gene is linked to neurofibromatosis, familial spinal, hereditary pheochromocytoma-paraganglioma, neurofibromatosis type 1, Watson syndrome, neurofibromatosis-Noonan syndrome, Moyamoya disease, familial ovarian cancer.

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3 link	c.6820G>A	p.Ala2274Thr	missense_variant, splice_region_variant	Exon 46 of 58	ENST00000358273.9	NP_001035957.1	P21359-1
NF1	NM_000267.3 link	c.6757G>A	p.Ala2253Thr	missense_variant, splice_region_variant	Exon 45 of 57		NP_000258.1	P21359-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9 link	c.6820G>A	p.Ala2274Thr	missense_variant, splice_region_variant	Exon 46 of 58	1	NM_001042492.3	ENSP00000351015.4		P21359-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.87e-7

AC:

AN:

1456598

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

725010

show subpopulations

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:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.63

BayesDel_addAF

Benign

-0.049

BayesDel_noAF

Benign

-0.31

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.63

D;.;T

Eigen

Uncertain

0.29

Eigen_PC

Uncertain

0.47

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.97

D;D;D

M_CAP

Uncertain

0.14

MetaRNN

Benign

0.26

T;T;T

MetaSVM

Benign

-0.83

MutationAssessor

Benign

1.8

L;.;.

PrimateAI

Uncertain

0.78

PROVEAN

Uncertain

-2.9

D;D;D

REVEL

Benign

0.10

Sift

Benign

0.11

T;T;T

Sift4G

Uncertain

0.015

D;D;D

Polyphen

0.0

B;B;.

Vest4

0.25

MutPred

0.40

Loss of helix (P = 0.079);.;.;

MVP

0.60

MPC

1.1

ClinPred

0.81

GERP RS

5.9

Varity_R

0.37

gMVP

0.55

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.89

SpliceAI score (max)

0.16

Details are displayed if max score is > 0.2

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

Publications

No publications associated with this variant yet.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over