16-1362526-AC-ACC

Variant names:

• chr16-1362526-A-AC
• rs756225251
• NM_032520.5:c.607dupC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_032520.5(GNPTG):​c.607dupC​(p.Gln203ProfsTer4) variant causes a frameshift, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000684 in 1,461,824 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. Q203Q) has been classified as Uncertain significance. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000068 (0 hom.)
• Consequence: GNPTG NM_032520.5 frameshift, splice_region
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:6
• Conservation: PhyloP100: 7.21
• Publications: 1 publications found

Genes affected

GNPTG (HGNC:23026): (N-acetylglucosamine-1-phosphate transferase subunit gamma) This gene encodes the gamma sunbunit of the N-acetylglucosamine-1-phosphotransferase complex. This hexameric complex, composed of alpha, beta and gamma subunits, catalyzes the first step in synthesis of a mannose 6-phosphate lysosomal recognition marker. This enzyme complex is necessary for targeting of lysosomal hydrolases to the lysosome. Mutations in the gene encoding the gamma subunit have been associated with mucolipidosis IIIC, also known as mucolipidosis III gamma.[provided by RefSeq, Feb 2010]

GNPTG Gene-Disease associations (from GenCC):

• GNPTG-mucolipidosis

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, G2P, Orphanet, Labcorp Genetics (formerly Invitae), ClinGen, Myriad Women’s Health

ACMG classification

Our verdict: Pathogenic. The variant received 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 16-1362526-A-AC is Pathogenic according to our data. Variant chr16-1362526-A-AC is described in ClinVar as Pathogenic. ClinVar VariationId is 553164.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_032520.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNPTG	NM_032520.5	MANE Select	c.607dupC	p.Gln203ProfsTer4	frameshift splice_region	Exon 8 of 11	NP_115909.1	Q9UJJ9

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNPTG	ENST00000204679.9	TSL:1 MANE Select	c.607dupC	p.Gln203ProfsTer4	frameshift splice_region	Exon 8 of 11	ENSP00000204679.4	Q9UJJ9
	GNPTG	ENST00000891792.1		c.727dupC	p.Gln243ProfsTer4	frameshift splice_region	Exon 9 of 12	ENSP00000561851.1
	GNPTG	ENST00000529110.2	TSL:2	c.691dupC	p.Gln231ProfsTer4	frameshift splice_region	Exon 7 of 10	ENSP00000435349.2	H0YEA7

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.0000279 AC: 7 AN: 250780 AF XY: 0.0000221

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000441

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000684 AC: 10 AN: 1461824 Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4 AN XY: 727222

African (AFR) AF: 0.00 AC: 0 AN: 33476

American (AMR) AF: 0.00 AC: 0 AN: 44720

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: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53368

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

European-Non Finnish (NFE) AF: 0.00000719 AC: 8 AN: 1112004

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	-	-	GNPTG-mucolipidosis (3)
2	-	-	not provided (2)
1	-	-	Rod-cone dystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.2
Mutation Taster		=4/196	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs756225251; hg19: chr16-1412527;