chr4-123028316-A-G

Position:

• chr4-123028316-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The ENST00000274008.5(AFG2A):​c.2000A>G​(p.Tyr667Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,856 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y667H) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: AFG2A ENST00000274008.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 8.76

Genes affected

SPATA5 (HGNC:):

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
SPATA5	NM_145207.3	c.2000A>G	p.Tyr667Cys	missense_variant	11/16	ENST00000274008.5	NP_660208.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
AFG2A	ENST00000274008.5	c.2000A>G	p.Tyr667Cys	missense_variant	11/16	1	NM_145207.3	ENSP00000274008	P1
AFG2A	ENST00000422835.2	n.2042A>G		non_coding_transcript_exon_variant	11/15	1
AFG2A	ENST00000675612.1	c.2069A>G	p.Tyr690Cys	missense_variant	12/17			ENSP00000502453

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461856 Hom.: 0 Cov.: 31 AF XY: 0.00000550 AC XY: 4 AN XY: 727228

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000540

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Microcephaly-intellectual disability-sensorineural hearing loss-epilepsy-abnormal muscle tone syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jun 14, 2022

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 667 of the SPATA5 protein (p.Tyr667Cys). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with SPATA5-related conditions. ClinVar contains an entry for this variant (Variation ID: 542386). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt SPATA5 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.84
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.74	T
PROVEAN	Pathogenic	-8.5	D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.89
MutPred		0.78		Loss of glycosylation at P670 (P = 0.0112);
MVP		0.97
MPC		0.71
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.90
gMVP		0.91

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

Publications

LitVar

Other links and lift over

dbSNP: rs998357703; hg19: chr4-123949471;