NM_001128227.3:c.622C>G

Variant names:

• chr9-36246118-G-C
• rs539332585
• NM_001128227.3:c.622C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_001128227.3(GNE):​c.622C>G​(p.Arg208Gly) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,830 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R208H) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: GNE NM_001128227.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.85
• Publications: 0 publications found

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

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_001128227.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-36246118-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 553400.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP2: Missense variant in the GNE gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 44 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Gene score misZ: 2.5904 (below the threshold of 3.09). Trascript score misZ: 4.032 (above the threshold of 3.09). GenCC associations: The gene is linked to sialuria, GNE myopathy, congenital myopathy, platelet-type bleeding disorder 19, macrothrombocytopenia, isolated.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.832

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001128227.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNE	NM_001128227.3	MANE Plus Clinical	c.622C>G	p.Arg208Gly	missense	Exon 3 of 12	NP_001121699.1
	GNE	NM_005476.7	MANE Select	c.529C>G	p.Arg177Gly	missense	Exon 3 of 12	NP_005467.1
	GNE	NM_001374797.1		c.529C>G	p.Arg177Gly	missense	Exon 3 of 11	NP_001361726.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNE	ENST00000396594.8	TSL:1 MANE Plus Clinical	c.622C>G	p.Arg208Gly	missense	Exon 3 of 12	ENSP00000379839.3
	GNE	ENST00000642385.2	MANE Select	c.529C>G	p.Arg177Gly	missense	Exon 3 of 12	ENSP00000494141.2
	GNE	ENST00000543356.7	TSL:1	c.352C>G	p.Arg118Gly	missense	Exon 2 of 11	ENSP00000437765.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461830 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727220

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86254

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111960

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00109982), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.61
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.95	D
Eigen	Pathogenic	0.69
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.75	D
MetaRNN	Pathogenic	0.83	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.7	M
PhyloP100		4.8
PrimateAI	Pathogenic	0.81	D
PROVEAN	Uncertain	-2.9	D
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0020	D
Sift4G	Benign	0.17	T
Polyphen		0.99	D
Vest4		0.81
MutPred		0.59		Loss of solvent accessibility (P = 0.239)
MVP		0.98
MPC		1.3
ClinPred		0.96	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.89
gMVP		0.96
Mutation Taster		=8/92	disease causing

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

Other links and lift over

dbSNP: rs539332585; hg19: chr9-36246115;