rs864622499

chr8-24955548-C-Gchr8-24955548-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP5

The NM_006158.5(NEFL):c.968G>C(p.Arg323Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R323W) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NEFL NM_006158.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2
• Conservation: PhyloP100: 3.75

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a region_of_interest Coil 2B (size 115) in uniprot entity NFL_HUMAN there are 15 pathogenic changes around while only 1 benign (94%) in NM_006158.5
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 8-24955548-C-G is Pathogenic according to our data. Variant chr8-24955548-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 220372.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=1, Uncertain_significance=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NEFL	NM_006158.5	c.968G>C	p.Arg323Pro	missense_variant	1/4	ENST00000610854.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NEFL	ENST00000610854.2	c.968G>C	p.Arg323Pro	missense_variant	1/4	1	NM_006158.5	P1
NEFL	ENST00000615973.1	n.1174G>C		non_coding_transcript_exon_variant	1/1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Sep 06, 2023

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 323 of the NEFL protein (p.Arg323Pro). For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 220372). This missense change has been observed in individuals with clinical features of 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). -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Sep 21, 2016

- -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 20, 2022

The p.R323P variant (also known as c.968G>C), located in coding exon 1 of the NEFL gene, results from a G to C substitution at nucleotide position 968. The arginine at codon 323 is replaced by proline, an amino acid with dissimilar 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.26
Cadd	Pathogenic	36
Dann	Benign	0.94
DEOGEN2	Pathogenic	0.93	D;.;T
FATHMM_MKL	Uncertain	0.89	D
LIST_S2	Uncertain	0.90	D;D;D
MetaRNN	Uncertain	0.68	D;D;D
PrimateAI	Uncertain	0.60	T
Sift4G	Uncertain	0.0030	D;.;D
Polyphen		0.77	P;.;.
Vest4		0.83
MVP		0.77
GERP RS		5.1
Varity_R		0.93
gMVP		0.98

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: rs864622499; hg19: chr8-24813062;