chr8-24955634-G-T

Variant names:

• chr8-24955634-G-T
• rs946938553
• NM_006158.5:c.882C>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP4

The NM_006158.5(NEFL):​c.882C>A​(p.Asn294Lys) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEFL NM_006158.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.73
• Publications: 0 publications found

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]

NEFL Gene-Disease associations (from GenCC):

• Charcot-Marie-Tooth disease

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• Charcot-Marie-Tooth disease type 2

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Charcot-Marie-Tooth disease type 1F

  Inheritance: AR, AD Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• Charcot-Marie-Tooth disease type 2E

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Charcot-Marie-Tooth disease type 2B5

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000272157 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a region_of_interest Coil 2B (size 115) in uniprot entity NFL_HUMAN there are 9 pathogenic changes around while only 1 benign (90%) in NM_006158.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 19 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Trascript score misZ: 0.63774 (below the threshold of 3.09). GenCC associations: The gene is linked to Charcot-Marie-Tooth disease type 2B5, Charcot-Marie-Tooth disease type 2, Charcot-Marie-Tooth disease type 2E, Charcot-Marie-Tooth disease, Charcot-Marie-Tooth disease type 1F.
• BP4: Computational evidence support a benign effect (MetaRNN=0.39063084).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006158.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NEFL	NM_006158.5	MANE Select	c.882C>A	p.Asn294Lys	missense	Exon 1 of 4	NP_006149.2

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NEFL	ENST00000610854.2	TSL:1 MANE Select	c.882C>A	p.Asn294Lys	missense	Exon 1 of 4	ENSP00000482169.2
	NEFL	ENST00000615973.1	TSL:6	n.1088C>A		non_coding_transcript_exon	Exon 1 of 1
	ENSG00000272157	ENST00000607735.3	TSL:6	n.-57G>T		upstream_gene	N/A

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 36

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Jul 01, 2016

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces asparagine with lysine at codon 294 of the NEFL protein (p.Asn294Lys). The asparagine residue is highly conserved and there is a moderate physicochemical difference between asparagine and lysine. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with an NEFL-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. In summary, this variant is a novel missense change with uncertain impact on protein function. Therefore, it has been classified as a Variant of Uncertain Significance.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Uncertain	0.046	T
BayesDel_noAF	Benign	-0.17
CADD	Pathogenic	34
DANN	Benign	0.97
DEOGEN2	Pathogenic	0.87	D
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.92	D
MetaRNN	Benign	0.39	T
PhyloP100		5.7
PrimateAI	Uncertain	0.65	T
Sift4G	Uncertain	0.0070	D
Polyphen		0.59	P
Vest4		0.38
MVP		0.80
GERP RS		3.9
Varity_R		0.35
gMVP		0.85

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

Other links and lift over

dbSNP: rs946938553; hg19: chr8-24813148;