18-12351335-G-A

Position:

• chr18-12351335-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PP3_Strong

The NM_006796.3(AFG3L2):​c.1397C>T​(p.Pro466Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: AFG3L2 NM_006796.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 9.97

Genes affected

AFG3L2 (HGNC:315): (AFG3 like matrix AAA peptidase subunit 2) This gene encodes a protein localized in mitochondria and closely related to paraplegin. The paraplegin gene is responsible for an autosomal recessive form of hereditary spastic paraplegia. This gene is a candidate gene for other hereditary spastic paraplegias or neurodegenerative disorders. [provided by RefSeq, Jul 2008]

AFG3L2 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.991

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
AFG3L2	NM_006796.3	c.1397C>T	p.Pro466Leu	missense_variant	11/17	ENST00000269143.8	NP_006787.2
AFG3L2	XM_011525601.4	c.1397C>T	p.Pro466Leu	missense_variant	11/16		XP_011523903.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AFG3L2	ENST00000269143.8	c.1397C>T	p.Pro466Leu	missense_variant	11/17	1	NM_006796.3	ENSP00000269143.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000809

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Asia WGS AF: 0.000289 AC: 1 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	May 09, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jun 07, 2022	This missense change has been observed in individual(s) with clinical features of AFG3L2-related conditions (PMID: 26633542). 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 AFG3L2 protein function. ClinVar contains an entry for this variant (Variation ID: 214053). This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 466 of the AFG3L2 protein (p.Pro466Leu). -

Spinocerebellar ataxia type 28;C3280977:Spastic ataxia 5 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Aug 22, 2016

- -

Spinocerebellar ataxia type 28 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Pathogenic	32
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.66	D
MutationAssessor	Pathogenic	3.6	H
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-9.7	D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.90		Loss of sheet (P = 0.0817);
MVP		0.91
MPC		2.0
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.98
gMVP		0.90

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: rs375098002; hg19: chr18-12351334;