Genetic Variant AFG3L2:p.Arg702Gln (chr18-12337411-C-T) – ACMG Classification: Pathogenic (19 pts)

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_006796.3(AFG3L2):c.2105G>A(p.Arg702Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,613,910 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R702L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

AFG3L2
NM_006796.3 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 7.54

Publications

10 publications found

Variant links:

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 links:

TUBB6 (HGNC:20776): (tubulin beta 6 class V) Predicted to enable GTP binding activity. Predicted to be a structural constituent of cytoskeleton. Predicted to be involved in microtubule cytoskeleton organization and mitotic cell cycle. Located in microtubule. [provided by Alliance of Genome Resources, Apr 2022]

TUBB6 Gene-Disease associations (from GenCC):

facial palsy, congenital, with ptosis and velopharyngeal dysfunction
Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

TUBB6 links:

LOC107985154 (HGNC:):

LOC107985154 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_006796.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr18-12337411-C-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3775947.Status of the report is criteria_provided_single_submitter, 1 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 37 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: 1.988 (below the threshold of 3.09). Trascript score misZ: 3.0639 (below the threshold of 3.09). GenCC associations: The gene is linked to spastic ataxia 5, optic atrophy 12, spinocerebellar ataxia type 28.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.979

PP5

Variant 18-12337411-C-T is Pathogenic according to our data. Variant chr18-12337411-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 5473.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_006796.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AFG3L2	NM_006796.3	MANE Select	c.2105G>A	p.Arg702Gln	missense	Exon 16 of 17	NP_006787.2	Q9Y4W6

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
AFG3L2	ENST00000269143.8	TSL:1 MANE Select	c.2105G>A	p.Arg702Gln	missense	Exon 16 of 17	ENSP00000269143.2	Q9Y4W6
AFG3L2	ENST00000889396.1		c.2312G>A	p.Arg771Gln	missense	Exon 17 of 18	ENSP00000559455.1
AFG3L2	ENST00000964861.1		c.2249G>A	p.Arg750Gln	missense	Exon 17 of 18	ENSP00000634920.1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251470

AF XY:

0.00

show subpopulations

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461696

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727168

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86248

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111840

Other (OTH)

AF:

0.0000166

AC:

AN:

60388

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.492

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152214

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74374

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41440

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10622

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

68036

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

ClinVar submissions

Significance:Pathogenic/Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

not provided (3)

Spinocerebellar ataxia type 28 (2)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.65

BayesDel_addAF

Pathogenic

0.40

BayesDel_noAF

Pathogenic

0.34

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.71

Eigen

Pathogenic

0.84

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Uncertain

0.95

LIST_S2

Pathogenic

0.99

M_CAP

Uncertain

0.17

MetaRNN

Pathogenic

0.98

MetaSVM

Uncertain

0.67

MutationAssessor

Uncertain

2.5

PhyloP100

7.5

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-3.6

REVEL

Pathogenic

0.80

Sift

Benign

0.052

Sift4G

Uncertain

0.019

Polyphen

1.0

Vest4

0.97

MutPred

0.83

Loss of helix (P = 0.0626)

MVP

0.98

MPC

0.74

ClinPred

0.98

GERP RS

5.6

Varity_R

0.77

gMVP

0.78

Mutation Taster

=16/84

disease causing (ClinVar)

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over