rs121908625

Positions:

• chr9-36219927-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The NM_005476.7(GNE):​c.1727G>A​(p.Gly576Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,858 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 Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GNE NM_005476.7 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: 7.33

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 Likely_pathogenic. Variant got 8 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 3.9915 (greater than threshold 3.09). GenCC has associacion of gene with macrothrombocytopenia, isolated, platelet-type bleeding disorder 19, sialuria, GNE myopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98
• PP5: Variant 9-36219927-C-T is Pathogenic according to our data. Variant chr9-36219927-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 6026.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}. Variant chr9-36219927-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNE	NM_001128227.3	c.1820G>A	p.Gly607Glu	missense_variant	10/12	ENST00000396594.8	NP_001121699.1
GNE	NM_005476.7	c.1727G>A	p.Gly576Glu	missense_variant	10/12	ENST00000642385.2	NP_005467.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNE	ENST00000396594.8	c.1820G>A	p.Gly607Glu	missense_variant	10/12	1	NM_001128227.3	ENSP00000379839.3
GNE	ENST00000642385.2	c.1727G>A	p.Gly576Glu	missense_variant	10/12		NM_005476.7	ENSP00000494141.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000795 AC: 2 AN: 251486 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135918

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461858 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

GNE myopathy Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Dec 01, 2023	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Sep 01, 2001	- -

Sialuria;C1853926:GNE myopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 03, 2023

This sequence change replaces glycine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 607 of the GNE protein (p.Gly607Glu). This variant is present in population databases (rs121908625, gnomAD 0.003%). This missense change has been observed in individual(s) with autosomal recessive inclusion body myopathy (PMID: 11528398). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is also known as G576E. ClinVar contains an entry for this variant (Variation ID: 6026). Advanced 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 at Invitae 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 GNE protein function. Experimental studies have shown that this missense change affects GNE function (PMID: 16503651). 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	Pathogenic	0.95
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.89	D;.;D;.;.;.;D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.97	.;D;D;D;D;D;.
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	1.8	L;.;L;.;.;.;L
PrimateAI	Pathogenic	0.80	T
PROVEAN	Benign	-1.7	.;N;N;.;D;N;N
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	.;D;D;.;D;D;D
Sift4G	Pathogenic	0.0	.;D;D;D;D;D;D
Polyphen		1.0	D;D;D;.;.;.;D
Vest4		0.99, 0.97, 0.96, 0.98, 0.99
MutPred		0.92		Gain of disorder (P = 0.122);.;Gain of disorder (P = 0.122);.;.;.;Gain of disorder (P = 0.122);
MVP		1.0
MPC		1.7
ClinPred		0.88	D
GERP RS		5.8
Varity_R		0.95
gMVP		0.99

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs121908625; hg19: chr9-36219924;