5-74721774-T-G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_032380.5(GFM2):c.2221A>C(p.Thr741Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,611,422 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 (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 6.9e-7 ( 0 hom. )

Consequence

GFM2
NM_032380.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.67

Variant links:

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]

GFM2 links:

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]

HEXB links:

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ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.932

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GFM2	NM_032380.5 link	c.2221A>C	p.Thr741Pro	missense_variant	Exon 21 of 21	ENST00000296805.8	NP_115756.2	Q969S9-1A0A024RAK1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GFM2	ENST00000296805.8 link	c.2221A>C	p.Thr741Pro	missense_variant	Exon 21 of 21	1	NM_032380.5	ENSP00000296805.3		Q969S9-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

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:

0.0000941

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

6.85e-7

AC:

AN:

1459224

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

725842

show subpopulations

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:

9.00e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74366

show subpopulations

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:

0.0000941

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not provided

Uncertain:1

Oct 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces threonine, which is neutral and polar, with proline, which is neutral and non-polar, at codon 741 of the GFM2 protein (p.Thr741Pro). This variant is present in population databases (no rsID available, gnomAD 0.03%). This variant has not been reported in the literature in individuals affected with GFM2-related conditions. ClinVar contains an entry for this variant (Variation ID: 2099061). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GFM2 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

Uncertain

0.39

BayesDel_addAF

Pathogenic

0.37

BayesDel_noAF

Pathogenic

0.30

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Benign

0.035

T;.;T

Eigen

Pathogenic

0.79

Eigen_PC

Pathogenic

0.75

FATHMM_MKL

Pathogenic

1.0

LIST_S2

Uncertain

0.93

.;D;D

M_CAP

Uncertain

0.17

MetaRNN

Pathogenic

0.93

D;D;D

MetaSVM

Uncertain

-0.038

MutationAssessor

Pathogenic

3.2

M;.;M

PrimateAI

Uncertain

0.52

PROVEAN

Uncertain

-4.4

D;D;D

REVEL

Pathogenic

0.78

Sift

Uncertain

0.0040

D;D;D

Sift4G

Uncertain

0.0040

D;D;D

Polyphen

1.0

D;D;D

Vest4

0.70

MutPred

0.80

Loss of catalytic residue at T741 (P = 0.0151);.;Loss of catalytic residue at T741 (P = 0.0151);

MVP

0.91

MPC

0.77

ClinPred

1.0

GERP RS

5.8

Varity_R

0.95

gMVP

0.87

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over