4-122923207-C-G

Variant names:

• chr4-122923207-C-G
• rs1560780127
• NM_145207.3:c.65C>G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_145207.3(AFG2A):​c.65C>G​(p.Ser22Cys) variant causes a missense change involving the alteration of a non-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 benign outcome for this variant. 13/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: AFG2A NM_145207.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.457

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]

NUDT6 (HGNC:8053): (nudix hydrolase 6) This gene overlaps and lies on the opposite strand from FGF2 gene, and is thought to be the FGF2 antisense gene. The two genes are independently transcribed, and their expression shows an inverse relationship, suggesting that this antisense transcript may regulate FGF2 expression. This gene has also been shown to have hormone-regulatory and antiproliferative actions in the pituitary that are independent of FGF2 expression. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Oct 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.09724885).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
AFG2A	NM_145207.3	c.65C>G	p.Ser22Cys	missense_variant	Exon 1 of 16	ENST00000274008.5	NP_660208.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SPATA5	ENST00000274008.5	c.65C>G	p.Ser22Cys	missense_variant	Exon 1 of 16	1	NM_145207.3	ENSP00000274008.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461888 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727244

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

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

Apr 16, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces serine with cysteine at codon 22 of the SPATA5 protein (p.Ser22Cys). The serine residue is moderately conserved and there is a moderate physicochemical difference between serine and cysteine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with SPATA5-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The cysteine amino acid residue is found in multiple mammalian species, suggesting that this missense change does not adversely affect protein function. These predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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	0.086
BayesDel_addAF	Uncertain	0.048	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	12
DANN	Uncertain	0.98
DEOGEN2	Benign	0.012	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-1.1
FATHMM_MKL	Benign	0.027	N
LIST_S2	Benign	0.32	T
M_CAP	Benign	0.027	D
MetaRNN	Benign	0.097	T
MetaSVM	Uncertain	-0.15	T
PrimateAI	Benign	0.44	T
PROVEAN	Benign	-0.98	N
REVEL	Benign	0.13
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.0020	B
Vest4		0.20
MutPred		0.24		Gain of glycosylation at S25 (P = 0.0175);
MVP		0.53
MPC		0.14
ClinPred		0.15	T
GERP RS		1.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.11
gMVP		0.17

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

Publications

LitVar

Other links and lift over

dbSNP: rs1560780127; hg19: chr4-123844362; COSMIC: COSV56782397; COSMIC: COSV56782397;