5-74722384-T-C

Variant summary

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

The NM_032380.5(GFM2):c.2206A>G(p.Ile736Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000322 in 1,613,176 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000031 (0 hom.)
• Consequence: GFM2 NM_032380.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.85

Genes affected

GFM2 (HGNC:29682): (GTP dependent ribosome recycling factor mitochondrial 2) Eukaryotes contain two protein translational systems, one in the cytoplasm and one in the mitochondria. Mitochondrial translation is crucial for maintaining mitochondrial function and mutations in this system lead to a breakdown in the respiratory chain-oxidative phosphorylation system and to impaired maintenance of mitochondrial DNA. This gene encodes one of the mitochondrial translation elongation factors, which is a GTPase that plays a role at the termination of mitochondrial translation by mediating the disassembly of ribosomes from messenger RNA . Its role in the regulation of normal mitochondrial function and in disease states attributed to mitochondrial dysfunction is not known. Alternative splicing results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2013]

HEXB (HGNC:4879): (hexosaminidase subunit beta) Hexosaminidase B is the beta subunit of the lysosomal enzyme beta-hexosaminidase that, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Beta-hexosaminidase is composed of two subunits, alpha and beta, which are encoded by separate genes. Both beta-hexosaminidase alpha and beta subunits are members of family 20 of glycosyl hydrolases. Mutations in the alpha or beta subunit genes lead to an accumulation of GM2 ganglioside in neurons and neurodegenerative disorders termed the GM2 gangliosidoses. Beta subunit gene mutations lead to Sandhoff disease (GM2-gangliosidosis type II). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2014]

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=0.16895711).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GFM2	NM_032380.5	c.2206A>G	p.Ile736Val	missense_variant	20/21	ENST00000296805.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GFM2	ENST00000296805.8	c.2206A>G	p.Ile736Val	missense_variant	20/21	1	NM_032380.5	P1

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152236 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000882

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000279 AC: 7 AN: 250552 Hom.: 0 AF XY: 0.0000443 AC XY: 6 AN XY: 135436

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000655

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000353

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000315 AC: 46 AN: 1460940 Hom.: 0 Cov.: 30 AF XY: 0.0000344 AC XY: 25 AN XY: 726776

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000348

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000369

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152236 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74384

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000882

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000967 Hom.: 0

Bravo AF: 0.0000340

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Combined oxidative phosphorylation deficiency 39 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Baylor Genetics

May 03, 2022

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.28	T
BayesDel_noAF	Benign	-0.46
Cadd	Benign	16
Dann	Uncertain	0.99
DEOGEN2	Benign	0.0024	T;.;T
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.012
FATHMM_MKL	Uncertain	0.95	D
M_CAP	Benign	0.023	T
MetaRNN	Benign	0.17	T;T;T
MetaSVM	Benign	-0.95	T
MutationAssessor	Benign	0.040	N;.;N
MutationTaster	Benign	0.89	D;D;D
PrimateAI	Benign	0.37	T
PROVEAN	Benign	-0.65	N;N;N
REVEL	Benign	0.11
Sift	Uncertain	0.010	D;D;D
Sift4G	Uncertain	0.016	D;D;D
Polyphen		0.0080	B;B;B
Vest4		0.089
MVP		0.72
MPC		0.13
ClinPred		0.12	T
GERP RS		4.8
Varity_R		0.13
gMVP		0.51

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: rs770911457; hg19: chr5-74018209; COSMIC: COSV54668955; COSMIC: COSV54668955;