9-36219884-G-T

Position:

• chr9-36219884-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_005476.7(GNE):​c.1770C>A​(p.Tyr590*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,852 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Y590Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GNE NM_005476.7 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 0.825

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 Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-36219884-G-T is Pathogenic according to our data. Variant chr9-36219884-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 489077.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNE	NM_001128227.3	c.1863C>A	p.Tyr621*	stop_gained	10/12	ENST00000396594.8	NP_001121699.1
GNE	NM_005476.7	c.1770C>A	p.Tyr590*	stop_gained	10/12	ENST00000642385.2	NP_005467.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNE	ENST00000396594.8	c.1863C>A	p.Tyr621*	stop_gained	10/12	1	NM_001128227.3	ENSP00000379839.3
GNE	ENST00000642385.2	c.1770C>A	p.Tyr590*	stop_gained	10/12		NM_005476.7	ENSP00000494141.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461852 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727220

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: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Sialuria;C1853926:GNE myopathy Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 03, 2022

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 489077). 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 creates a premature translational stop signal (p.Tyr621*) in the GNE gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GNE are known to be pathogenic (PMID: 24027297). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Oct 31, 2017

The Y621X variant in the GNE gene has not been reported previously as a pathogenic variant nor as a benign variant, to our knowledge. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The variant is not observed in large population cohorts (Lek et al., 2016). We interpret Y621X as a pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Uncertain	0.26
Eigen_PC	Benign	0.11
FATHMM_MKL	Uncertain	0.78	D
Vest4		0.98, 0.98, 0.98
GERP RS		1.9

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.19		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: rs111302956; hg19: chr9-36219881;