chr8-24953786-C-G

Position:

• chr8-24953786-C-G

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_006158.5(NEFL):​c.1179G>C​(p.Leu393Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L393W) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEFL NM_006158.5 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 2.88

Genes affected

NEFL (HGNC:7739): (neurofilament light chain) Neurofilaments are type IV intermediate filament heteropolymers composed of light, medium, and heavy chains. Neurofilaments comprise the axoskeleton and they functionally maintain the neuronal caliber. They may also play a role in intracellular transport to axons and dendrites. This gene encodes the light chain neurofilament protein. Mutations in this gene cause Charcot-Marie-Tooth disease types 1F (CMT1F) and 2E (CMT2E), disorders of the peripheral nervous system that are characterized by distinct neuropathies. A pseudogene has been identified on chromosome Y. [provided by RefSeq, Oct 2008]

MIR6841 (HGNC:50070): (microRNA 6841) microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a region_of_interest Coil 2B (size 115) in uniprot entity NFL_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_006158.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr8-24953787-A-C is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.943
• PP5: Variant 8-24953786-C-G is Pathogenic according to our data. Variant chr8-24953786-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 245748.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NEFL	NM_006158.5	c.1179G>C	p.Leu393Phe	missense_variant	3/4	ENST00000610854.2	NP_006149.2
MIR6841	NR_106900.1			downstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NEFL	ENST00000610854.2	c.1179G>C	p.Leu393Phe	missense_variant	3/4	1	NM_006158.5	ENSP00000482169	P1
MIR6841	ENST00000637129.1			downstream_gene_variant

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 2E Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 26, 2022

This missense change has been observed in individuals with autosomal dominant Charcot-Marie-Tooth disease (Invitae). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 393 of the NEFL protein (p.Leu393Phe). ClinVar contains an entry for this variant (Variation ID: 245748). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Feb 14, 2022

Has not been previously published as pathogenic or benign to our knowledge; Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -

Charcot-Marie-Tooth disease Uncertain:1

Uncertain significance, no assertion criteria provided

research

Genesis Genome Database

Aug 14, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	27
DANN	Benign	0.84
DEOGEN2	Pathogenic	0.95	D
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.94	D
PrimateAI	Pathogenic	0.83	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.88
MVP		0.76
GERP RS		5.9
Varity_R		0.73
gMVP		0.80

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs879253927; hg19: chr8-24811300;