4-123256131-T-A

Variant names:

• chr4-123256131-T-A
• rs149604630
• NM_145207.3:c.2456T>A

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2 PM5 PP2 PP3_Strong

The NM_145207.3(AFG2A):​c.2456T>A​(p.Val819Asp) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. V819A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: AFG2A NM_145207.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.79
• Publications: 0 publications found

Genes affected

AFG2A (HGNC:18119): (AFG2 AAA ATPase homolog A) This gene encodes a member of the ATPase associated with diverse activities family, whose members are defined by a highly conserved ATPase domain. Members of this family participate in diverse cellular processes that include membrane fusion, DNA replication, microtubule severing, and protein degradation. The protein encoded by this gene has a putative mitochondrial targeting sequence and has been proposed to function in maintenance of mitochondrial function and integrity during mouse spermatogenesis. Allelic variants in this gene have been associated with epilepsy, hearing loss, and cognitive disability syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Sep 2016]

AFG2A Gene-Disease associations (from GenCC):

• microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Orphanet, PanelApp Australia

ACMG classification

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

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr4-123256131-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 548622.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 22 curated pathogenic missense variants (we use a threshold of 10). The gene has 7 curated benign missense variants. Gene score misZ: 0.46019 (below the threshold of 3.09). Trascript score misZ: 1.2041 (below the threshold of 3.09). GenCC associations: The gene is linked to microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.953

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_145207.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AFG2A	NM_145207.3	MANE Select	c.2456T>A	p.Val819Asp	missense	Exon 15 of 16	NP_660208.2
	AFG2A	NM_001438322.1		c.2528T>A	p.Val843Asp	missense	Exon 16 of 17	NP_001425251.1
	AFG2A	NM_001437913.1		c.2525T>A	p.Val842Asp	missense	Exon 16 of 17	NP_001424842.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	AFG2A	ENST00000274008.5	TSL:1 MANE Select	c.2456T>A	p.Val819Asp	missense	Exon 15 of 16	ENSP00000274008.3
	AFG2A	ENST00000675612.1		c.2525T>A	p.Val842Asp	missense	Exon 16 of 17	ENSP00000502453.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.52
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Uncertain	0.13
CADD	Uncertain	24
DANN	Uncertain	0.98
DEOGEN2	Benign	0.24	T
Eigen	Uncertain	0.48
Eigen_PC	Uncertain	0.30
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.48	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	0.98	D
PhyloP100		6.8
PrimateAI	Benign	0.42	T
PROVEAN	Pathogenic	-6.3	D
REVEL	Pathogenic	0.77
Sift	Uncertain	0.0040	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.68
MutPred		0.68		Gain of disorder (P = 0.0066)
MVP		0.93
MPC		0.73
ClinPred		0.99	D
GERP RS		3.7
Varity_R		0.69
gMVP		0.75
Mutation Taster		=72/28	polymorphism

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: rs149604630; hg19: chr4-124177286;