18-12351335-G-C

Variant names:

• chr18-12351335-G-C
• rs375098002
• NM_006796.3:c.1397C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_006796.3(AFG3L2):​c.1397C>G​(p.Pro466Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P466L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AFG3L2 NM_006796.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.97
• Publications: 0 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]

AFG3L2 Gene-Disease associations (from GenCC):

• spinocerebellar ataxia type 28

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Illumina, Genomics England PanelApp
• spastic ataxia 5

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Orphanet, Labcorp Genetics (formerly Invitae), G2P
• optic atrophy 12

  Inheritance: AD Classification: STRONG Submitted by: Ambry Genetics

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 5 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
• 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, 0.988

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AFG3L2	NM_006796.3	c.1397C>G	p.Pro466Arg	missense_variant	Exon 11 of 17	ENST00000269143.8	NP_006787.2
AFG3L2	XM_011525601.4	c.1397C>G	p.Pro466Arg	missense_variant	Exon 11 of 16		XP_011523903.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AFG3L2	ENST00000269143.8	c.1397C>G	p.Pro466Arg	missense_variant	Exon 11 of 17	1	NM_006796.3	ENSP00000269143.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461888 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727246

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

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: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112008

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

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.33
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.92
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Uncertain	2.3	M
PhyloP100		10
PrimateAI	Pathogenic	0.82	D
PROVEAN	Pathogenic	-8.7	D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.010	D
Sift4G	Uncertain	0.0080	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.88		Gain of solvent accessibility (P = 0.0584);
MVP		0.93
MPC		2.1
ClinPred		0.99	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.96
gMVP		0.90
Mutation Taster		=12/88	disease causing

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: rs375098002; hg19: chr18-12351334;