rs756114856

Variant names:

• chr8-24955695-T-C
• rs756114856
• NM_006158.5:c.821A>G

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 5P and 1B. PM1 PM2 PP2 BP6

The NM_006158.5(NEFL):​c.821A>G​(p.Gln274Arg) 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. Q274E) 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 U:1 B:1
• Conservation: PhyloP100: 6.12
• 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 hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain 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.
• BP6: Variant 8-24955695-T-C is Benign according to our data. Variant chr8-24955695-T-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 412304.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NEFL	NM_006158.5	c.821A>G	p.Gln274Arg	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.821A>G	p.Gln274Arg	missense_variant	Exon 1 of 4	1	NM_006158.5	ENSP00000482169.2
ENSG00000272157	ENST00000607735.3	n.5T>C		non_coding_transcript_exon_variant	Exon 1 of 1	6
NEFL	ENST00000615973.1	n.1027A>G		non_coding_transcript_exon_variant	Exon 1 of 1	6

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000401 AC: 1 AN: 249086 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 37

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

ExAC AF: 0.00000825 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Sep 25, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.821A>G (p.Q274R) alteration is located in exon 1 (coding exon 1) of the NEFL gene. This alteration results from a A to G substitution at nucleotide position 821, causing the glutamine (Q) at amino acid position 274 to be replaced by an arginine (R). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

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

Jan 19, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.30
BayesDel_addAF	Pathogenic	0.31	D
BayesDel_noAF	Pathogenic	0.21
CADD	Pathogenic	33
DANN	Benign	0.90
DEOGEN2	Pathogenic	0.82	D
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Benign	0.60	T
MetaRNN	Uncertain	0.58	D
PhyloP100		6.1
PrimateAI	Uncertain	0.67	T
Sift4G	Uncertain	0.026	D
Polyphen		0.19	B
Vest4		0.55
MVP		0.70
GERP RS		5.5
Varity_R		0.65
gMVP		0.74

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: rs756114856; hg19: chr8-24813209;