rs151344514

Variant names:

• chr18-12337520-T-C
• rs151344514
• NM_006796.3:c.1996A>G

Your query was ambiguous. Multiple possible variants found:

• chr18-12337520-T-C
• chr18-12337520-T-A

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1 PM2 PM5 PP2 PP3_Strong PP5_Very_Strong

The NM_006796.3(AFG3L2):​c.1996A>G​(p.Met666Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,860 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. M666R) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: AFG3L2 NM_006796.3 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 O:1
• Conservation: PhyloP100: 7.64
• Publications: 9 publications found

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]

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)

LOC107985154 (HGNC:):

ACMG classification

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

• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 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 chr18-12337519-A-C is described in ClinVar as Pathogenic. ClinVar VariationId is 30424.Status of the report is no_assertion_criteria_provided, 0 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 spinocerebellar ataxia type 28, spastic ataxia 5, optic atrophy 12.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.981
• PP5: Variant 18-12337520-T-C is Pathogenic according to our data. Variant chr18-12337520-T-C is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 30423.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.1996A>G	p.Met666Val	missense	Exon 16 of 17	NP_006787.2	Q9Y4W6

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AFG3L2	ENST00000269143.8	TSL:1 MANE Select	c.1996A>G	p.Met666Val	missense	Exon 16 of 17	ENSP00000269143.2	Q9Y4W6
	AFG3L2	ENST00000889396.1		c.2203A>G	p.Met735Val	missense	Exon 17 of 18	ENSP00000559455.1
	AFG3L2	ENST00000964861.1		c.2140A>G	p.Met714Val	missense	Exon 17 of 18	ENSP00000634920.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461860 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727232

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111982

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
2	-	-	not provided (2)
1	-	-	Spinocerebellar ataxia type 28 (2)
1	-	-	Spinocerebellar ataxia type 28;C3280977:Spastic ataxia 5;C5436534:Optic atrophy 12 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.82	T
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.98	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.8	H
PhyloP100		7.6
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-3.7	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		0.99	D
Vest4		0.97
MutPred		0.87		Gain of helix (P = 0.132)
MVP		0.94
MPC		0.70
ClinPred		1.0	D
GERP RS		5.6
Varity_R		0.91
gMVP		0.89
Mutation Taster		=26/74	disease causing (ClinVar)

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: rs151344514; hg19: chr18-12337519;