rs1057522195

chr18-12356794-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP3_Strong PP5

The NM_006796.3(AFG3L2):c.1064C>T(p.Thr355Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T355T) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: AFG3L2 NM_006796.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3 U:2
• Conservation: PhyloP100: 10.0

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.953
• PP5: Variant 18-12356794-G-A is Pathogenic according to our data. Variant chr18-12356794-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 385335.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=2, Pathogenic=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
AFG3L2	NM_006796.3	c.1064C>T	p.Thr355Met	missense_variant	9/17	ENST00000269143.8
AFG3L2	XM_011525601.4	c.1064C>T	p.Thr355Met	missense_variant	9/16

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
AFG3L2	ENST00000269143.8	c.1064C>T	p.Thr355Met	missense_variant	9/17	1	NM_006796.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3 Uncertain:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:2 Uncertain:1

Uncertain significance, criteria provided, single submitter	clinical testing	CeGaT Center for Human Genetics Tuebingen	Dec 01, 2019	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Aug 22, 2023	Not observed in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 32219868, 36974169, 36110148) -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Mar 24, 2023	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 AFG3L2 protein function. ClinVar contains an entry for this variant (Variation ID: 385335). This missense change has been observed in individuals with clinical features of autosomal dominant AFG3L2-related conditions (PMID: 32219868; Invitae). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with methionine, which is neutral and non-polar, at codon 355 of the AFG3L2 protein (p.Thr355Met). -

Dystonic disorder;C0029124:Optic atrophy;C1866129:Abnormal cerebellum morphology;C3887506:Hyperkinetic movements Pathogenic:1

Pathogenic, no assertion criteria provided

research

Neurogenetics, IRCCS Istituto delle Scienze Neurologiche di Bologna

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not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Nov 10, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
Cadd	Pathogenic	32
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.96	D
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	5.0	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.7	D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.91
MutPred		0.81		Loss of methylation at K354 (P = 0.0306);
MVP		0.99
MPC		2.1
ClinPred		1.0	D
GERP RS		5.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.94
gMVP		0.96

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: rs1057522195; hg19: chr18-12356793;