rs1554661032

Positions:

• chr9-36233950-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001128227.3(GNE):​c.1045C>G​(p.Leu349Val) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,780 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GNE NM_001128227.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 2.54

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 3 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNE	NM_001128227.3	c.1045C>G	p.Leu349Val	missense_variant	5/12	ENST00000396594.8	NP_001121699.1
GNE	NM_005476.7	c.952C>G	p.Leu318Val	missense_variant	5/12	ENST00000642385.2	NP_005467.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNE	ENST00000396594.8	c.1045C>G	p.Leu349Val	missense_variant	5/12	1	NM_001128227.3	ENSP00000379839
GNE	ENST00000642385.2	c.952C>G	p.Leu318Val	missense_variant	5/12		NM_005476.7	ENSP00000494141	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461780 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727198

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Sialuria;C1853926:GNE myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 19, 2022

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 529877). This variant has not been reported in the literature in individuals affected with GNE-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 349 of the GNE protein (p.Leu349Val). -

GNE myopathy Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Natera, Inc.

May 07, 2021

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Revvity Omics, Revvity

Feb 15, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Pathogenic	0.42	D
BayesDel_noAF	Pathogenic	0.37
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.69	D;.;D;.;.;.;D
Eigen	Benign	0.11
Eigen_PC	Benign	0.13
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	.;D;D;D;D;D;.
M_CAP	Pathogenic	0.58	D
MetaRNN	Uncertain	0.66	D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.81	D
MutationAssessor	Benign	0.44	N;.;N;.;.;N;N
MutationTaster	Benign	1.0	D;D;D;D;D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	0.13	.;N;N;.;N;N;N
REVEL	Pathogenic	0.65
Sift	Benign	0.21	.;T;T;.;D;D;T
Sift4G	Benign	0.29	.;T;T;T;T;T;T
Polyphen		0.98	D;P;D;.;.;.;D
Vest4		0.77, 0.77, 0.76, 0.73, 0.72
MutPred		0.70		Gain of disorder (P = 0.2335);.;Gain of disorder (P = 0.2335);.;.;Gain of disorder (P = 0.2335);Gain of disorder (P = 0.2335);
MVP		0.95
MPC		1.4
ClinPred		0.51	D
GERP RS		2.5
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.26
gMVP		0.78

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: rs1554661032; hg19: chr9-36233947;