9-36227253-T-C

Position:

• chr9-36227253-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_001128227.3(GNE):​c.1369A>G​(p.Met457Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000344 in 1,454,314 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: GNE NM_001128227.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.53

Genes affected

GNE (HGNC:23657): (glucosamine (UDP-N-acetyl)-2-epimerase/N-acetylmannosamine kinase) The protein encoded by this gene is a bifunctional enzyme that initiates and regulates the biosynthesis of N-acetylneuraminic acid (NeuAc), a precursor of sialic acids. It is a rate-limiting enzyme in the sialic acid biosynthetic pathway. Sialic acid modification of cell surface molecules is crucial for their function in many biologic processes, including cell adhesion and signal transduction. Differential sialylation of cell surface molecules is also implicated in the tumorigenicity and metastatic behavior of malignant cells. Mutations in this gene are associated with sialuria, autosomal recessive inclusion body myopathy, and Nonaka myopathy. Alternative splicing of this gene results in transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

CLTA (HGNC:2090): (clathrin light chain A) Clathrin is a large, soluble protein composed of heavy and light chains. It functions as the main structural component of the lattice-type cytoplasmic face of coated pits and vesicles which entrap specific macromolecules during receptor-mediated endocytosis. This gene encodes one of two clathrin light chain proteins which are believed to function as regulatory elements. Alternative splicing results in multiple transcript variants. Related pseudogenes have been identified on chromosomes 8 and 12. [provided by RefSeq, May 2010]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), GNE. . Gene score misZ 2.5904 (greater than the threshold 3.09). Trascript score misZ 4.032 (greater than threshold 3.09). GenCC has associacion of gene with macrothrombocytopenia, isolated, platelet-type bleeding disorder 19, sialuria, GNE myopathy.
• BP4: Computational evidence support a benign effect (MetaRNN=0.37619048).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNE	NM_001128227.3	c.1369A>G	p.Met457Val	missense_variant	7/12	ENST00000396594.8	NP_001121699.1
GNE	NM_005476.7	c.1276A>G	p.Met426Val	missense_variant	7/12	ENST00000642385.2	NP_005467.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNE	ENST00000396594.8	c.1369A>G	p.Met457Val	missense_variant	7/12	1	NM_001128227.3	ENSP00000379839
GNE	ENST00000642385.2	c.1276A>G	p.Met426Val	missense_variant	7/12		NM_005476.7	ENSP00000494141	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000344 AC: 5 AN: 1454314 Hom.: 0 Cov.: 30 AF XY: 0.00000276 AC XY: 2 AN XY: 723978

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.05e-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

Sialuria;C1853926:GNE myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 24, 2021

This sequence change replaces methionine with valine at codon 457 of the GNE protein (p.Met457Val). The methionine residue is highly conserved and there is a small physicochemical difference between methionine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with GNE-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C15"). 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	0.11
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Uncertain	0.12
CADD	Benign	21
DANN	Benign	0.97
DEOGEN2	Uncertain	0.69	D;.;D;.;.;.;D
Eigen	Benign	-0.33
Eigen_PC	Benign	-0.079
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	.;D;D;D;D;D;.
M_CAP	Pathogenic	0.43	D
MetaRNN	Benign	0.38	T;T;T;T;T;T;T
MetaSVM	Uncertain	0.55	D
MutationAssessor	Benign	-0.50	N;.;N;.;.;N;N
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.50	.;N;N;.;N;N;N
REVEL	Uncertain	0.48
Sift	Benign	0.054	.;T;T;.;T;T;T
Sift4G	Benign	0.28	.;T;T;T;T;T;T
Polyphen		0.092	B;B;B;.;.;.;B
Vest4		0.59, 0.60, 0.58, 0.58, 0.65, 0.60
MutPred		0.56		Loss of stability (P = 0.0793);.;Loss of stability (P = 0.0793);.;.;Loss of stability (P = 0.0793);Loss of stability (P = 0.0793);
MVP		0.88
MPC		0.63
ClinPred		0.79	D
GERP RS		3.5
Varity_R		0.50
gMVP		0.76

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: rs750404513; hg19: chr9-36227250;