8-24955828-C-T

Variant names:

• chr8-24955828-C-T
• rs758201328
• NM_006158.5:c.688G>A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PP2 PP3_Moderate

The NM_006158.5(NEFL):​c.688G>A​(p.Glu230Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,459,188 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E230D) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000013 (0 hom.)
• Consequence: NEFL NM_006158.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 6.09

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]

ENSG00000272157 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• 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 2, Charcot-Marie-Tooth disease type 1F, Charcot-Marie-Tooth disease, Charcot-Marie-Tooth disease type 2E, Charcot-Marie-Tooth disease type 2B5.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.917

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NEFL	NM_006158.5	c.688G>A	p.Glu230Lys	missense_variant	Exon 1 of 4	ENST00000610854.2	NP_006149.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NEFL	ENST00000610854.2	c.688G>A	p.Glu230Lys	missense_variant	Exon 1 of 4	1	NM_006158.5	ENSP00000482169.2
ENSG00000272157	ENST00000607735.3	n.138C>T		non_coding_transcript_exon_variant	Exon 1 of 1	6
NEFL	ENST00000615973.1	n.894G>A		non_coding_transcript_exon_variant	Exon 1 of 1	6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.0000130 AC: 19 AN: 1459188 Hom.: 0 Cov.: 36 AF XY: 0.0000110 AC XY: 8 AN XY: 726048

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50930

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

European-Non Finnish (NFE) AF: 0.0000126 AC: 14 AN: 1111850

Other (OTH) AF: 0.0000828 AC: 5 AN: 60358

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000936 Hom.: 0

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Mar 22, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.E230K variant (also known as c.688G>A), located in coding exon 1 of the NEFL gene, results from a G to A substitution at nucleotide position 688. The glutamic acid at codon 230 is replaced by lysine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

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

Aug 14, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ClinVar contains an entry for this variant (Variation ID: 412302). 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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt NEFL protein function. This variant has not been reported in the literature in individuals affected with NEFL-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 230 of the NEFL protein (p.Glu230Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	35
DANN	Benign	0.97
DEOGEN2	Pathogenic	0.93	D
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Pathogenic	1.0	D
MetaRNN	Pathogenic	0.92	D
PhyloP100		6.1
PrimateAI	Uncertain	0.71	T
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.80
MVP		0.74
GERP RS		5.3
Varity_R		0.78
gMVP		0.92

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: rs758201328; hg19: chr8-24813342;