16-1362287-AC-ACC

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_032520.5(GNPTG):​c.499dupC​(p.Leu167ProfsTer32) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,612,884 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L167L) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

GNPTG
NM_032520.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 7.36

Publications

3 publications found
Variant links:
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: ClinGen, Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, G2P, Genomics England PanelApp

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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 16-1362287-A-AC is Pathogenic according to our data. Variant chr16-1362287-A-AC is described in ClinVar as Pathogenic. ClinVar VariationId is 437454.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

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
GNPTG
NM_032520.5
MANE Select
c.499dupCp.Leu167ProfsTer32
frameshift
Exon 7 of 11NP_115909.1

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
GNPTG
ENST00000204679.9
TSL:1 MANE Select
c.499dupCp.Leu167ProfsTer32
frameshift
Exon 7 of 11ENSP00000204679.4
GNPTG
ENST00000529110.2
TSL:2
c.583dupCp.Leu195ProfsTer32
frameshift
Exon 6 of 10ENSP00000435349.2
GNPTG
ENST00000683887.1
c.547dupCp.Leu183ProfsTer32
frameshift
Exon 7 of 11ENSP00000506886.1

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
151942
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000484
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000441
AC:
11
AN:
249592
AF XY:
0.0000591
show subpopulations
Gnomad AFR exome
AF:
0.000125
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000710
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000199
AC:
29
AN:
1460942
Hom.:
0
Cov.:
33
AF XY:
0.0000220
AC XY:
16
AN XY:
726826
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26124
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86250
European-Finnish (FIN)
AF:
0.0000380
AC:
2
AN:
52608
Middle Eastern (MID)
AF:
0.000347
AC:
2
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000180
AC:
20
AN:
1111920
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
2
4
6
8
10
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000329
AC:
5
AN:
151942
Hom.:
0
Cov.:
33
AF XY:
0.0000270
AC XY:
2
AN XY:
74200
show subpopulations
African (AFR)
AF:
0.0000484
AC:
2
AN:
41344
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5162
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10606
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
67972
Other (OTH)
AF:
0.00
AC:
0
AN:
2080
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.455
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.000109
Hom.:
0
Bravo
AF:
0.0000378

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:8
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

GNPTG-mucolipidosis Pathogenic:7
Jul 22, 2021
Genome-Nilou Lab
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Aug 01, 2017
Counsyl
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com.

Mar 21, 2020
Revvity Omics, Revvity
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Sep 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

Jun 18, 2017
Genomic Research Center, Shahid Beheshti University of Medical Sciences
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Mar 01, 2000
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

Neuberg Centre For Genomic Medicine, NCGM
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The frame shift c.499dupC (p.Leu167Profs32) variant has been reported previously in homozygous state in several individuals affected with mucolipidosis III (Tüysüz B et al.,2017). The p.L167Pfs32 variant is observed in (0.0125%) alleles from individuals of African background in gnomAD Exomes and is novel (not in any individuals) in 1000 Genomes. This variant has been reported to ClinVar database as Pathogenic. This variant is predicted to cause loss of normal protein function through protein truncation. Loss of function variants have been previously reported to be disease causing. For these reasons, this variant has been classified as Pathogenic.

not provided Pathogenic:1
Feb 08, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Leu167Profs*32) in the GNPTG gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GNPTG are known to be pathogenic (PMID: 19370764, 20301784). This variant is present in population databases (rs756959430, gnomAD 0.008%). This premature translational stop signal has been observed in individuals with mucolipidosis III (PMID: 29170090). ClinVar contains an entry for this variant (Variation ID: 437454). For these reasons, this variant has been classified as Pathogenic.

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
PhyloP100
7.4
Mutation Taster
=1/199
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs756959430; hg19: chr16-1412288; COSMIC: COSV99201592; COSMIC: COSV99201592; API