NM_006796.3:c.1847A>T

Variant names:

• chr18-12340334-T-A
• rs387906889
• NM_006796.3:c.1847A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP2

The NM_006796.3(AFG3L2):​c.1847A>T​(p.Tyr616Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,022 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y616C) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AFG3L2 NM_006796.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.01
• Publications: 20 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: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 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 chr18-12340334-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 30427.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AFG3L2	NM_006796.3	c.1847A>T	p.Tyr616Phe	missense_variant	Exon 15 of 17	ENST00000269143.8	NP_006787.2
AFG3L2	XM_011525601.4	c.1780-2799A>T		intron_variant	Intron 14 of 15		XP_011523903.1
LOC107985154	XR_001753363.2	n.781+1754T>A		intron_variant	Intron 1 of 1
LOC107985154	XR_002958227.2	n.3291+3432T>A		intron_variant	Intron 1 of 1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
AFG3L2	ENST00000269143.8	c.1847A>T	p.Tyr616Phe	missense_variant	Exon 15 of 17	1	NM_006796.3	ENSP00000269143.2

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152214 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461808 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727198

African (AFR) AF: 0.0000299 AC: 1 AN: 33478

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

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

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53414

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111950

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

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152214 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74366

African (AFR) AF: 0.0000724 AC: 3 AN: 41458

American (AMR) AF: 0.00 AC: 0 AN: 15284

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5200

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10626

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68030

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000189

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.14
BayesDel_addAF	Uncertain	0.091	D
BayesDel_noAF	Benign	-0.11
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.67	D
Eigen	Benign	0.12
Eigen_PC	Benign	0.16
FATHMM_MKL	Uncertain	0.93	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.032	D
MetaRNN	Uncertain	0.60	D
MetaSVM	Benign	-0.32	T
MutationAssessor	Benign	1.3	L
PhyloP100		8.0
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-3.0	D
REVEL	Uncertain	0.41
Sift	Benign	0.18	T
Sift4G	Benign	0.26	T
Polyphen		0.58	P
Vest4		0.66
MutPred		0.43		Loss of ubiquitination at K618 (P = 0.0456);
MVP		0.89
MPC		1.3
ClinPred		0.98	D
GERP RS		4.5
Varity_R		0.49
gMVP		0.79
Mutation Taster		=76/24	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs387906889; hg19: chr18-12340333;