chr12-101788567-TTG-T

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PP5_Very_Strong

The NM_024312.5(GNPTAB):​c.344_345delCA​(p.Thr115AsnfsTer5) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000115 in 1,567,654 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. T115T) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6O:1

Conservation

PhyloP100: 2.00

Publications

2 publications found
Variant links:
Genes affected
GNPTAB (HGNC:29670): (N-acetylglucosamine-1-phosphate transferase subunits alpha and beta) This gene encodes two of three subunit types of the membrane-bound enzyme N-acetylglucosamine-1-phosphotransferase, a heterohexameric complex composed of two alpha, two beta, and two gamma subunits. The encoded protein is proteolytically cleaved at the Lys928-Asp929 bond to yield mature alpha and beta polypeptides while the gamma subunits are the product of a distinct gene (GeneID 84572). In the Golgi apparatus, the heterohexameric complex catalyzes the first step in the synthesis of mannose 6-phosphate recognition markers on certain oligosaccharides of newly synthesized lysosomal enzymes. These recognition markers are essential for appropriate trafficking of lysosomal enzymes. Mutations in this gene have been associated with both mucolipidosis II and mucolipidosis IIIA.[provided by RefSeq, May 2010]
GNPTAB Gene-Disease associations (from GenCC):
  • GNPTAB-mucolipidosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • mucolipidosis
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health
  • mucolipidosis type II
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), Ambry Genetics, PanelApp Australia, Genomics England PanelApp
  • mucolipidosis type III, alpha/beta
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, G2P, Genomics England PanelApp

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ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 16 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PP5
Variant 12-101788567-TTG-T is Pathogenic according to our data. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101788567-TTG-T is described in CliVar as Pathogenic/Likely_pathogenic. Clinvar id is 39073.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GNPTABNM_024312.5 linkc.344_345delCA p.Thr115AsnfsTer5 frameshift_variant Exon 4 of 21 ENST00000299314.12 NP_077288.2 Q3T906-1
GNPTABXM_011538731.3 linkc.263_264delCA p.Thr88AsnfsTer5 frameshift_variant Exon 4 of 21 XP_011537033.1
GNPTABXM_006719593.4 linkc.344_345delCA p.Thr115AsnfsTer5 frameshift_variant Exon 4 of 19 XP_006719656.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GNPTABENST00000299314.12 linkc.344_345delCA p.Thr115AsnfsTer5 frameshift_variant Exon 4 of 21 1 NM_024312.5 ENSP00000299314.7 Q3T906-1
GNPTABENST00000549940.5 linkc.344_345delCA p.Thr115AsnfsTer5 frameshift_variant Exon 4 of 11 1 ENSP00000449150.1 Q3T906-2
GNPTABENST00000550352.1 linkn.138_139delCA non_coding_transcript_exon_variant Exon 2 of 3 3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152248
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000478
AC:
12
AN:
251084
AF XY:
0.0000442
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000106
AC:
15
AN:
1415406
Hom.:
0
AF XY:
0.0000113
AC XY:
8
AN XY:
707264
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32622
American (AMR)
AF:
0.000246
AC:
11
AN:
44662
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25858
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39480
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53388
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5628
European-Non Finnish (NFE)
AF:
0.00000374
AC:
4
AN:
1069738
Other (OTH)
AF:
0.00
AC:
0
AN:
58778
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.435
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000197
AC:
3
AN:
152248
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74380
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41470
American (AMR)
AF:
0.000131
AC:
2
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5208
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:6Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II Pathogenic:2
May 15, 2018
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. -

Nov 13, 2023
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.Thr115Asnfs*5) in the GNPTAB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GNPTAB are known to be pathogenic (PMID: 19617216, 25107912). This variant is present in population databases (rs761987059, gnomAD 0.03%). This premature translational stop signal has been observed in individuals with mucolipidosis (PMID: 19617216). ClinVar contains an entry for this variant (Variation ID: 39073). For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:2
Jun 12, 2023
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Frameshift variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; This variant is associated with the following publications: (PMID: 24127423, 19617216, 30882951, 32182687, 25601403) -

Dec 02, 2016
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Mucolipidosis type II Pathogenic:1Other:1
Mar 16, 2020
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
GeneReviews
Significance:not provided
Review Status:no classification provided
Collection Method:literature only

- -

Mucolipidosis Pathogenic:1
Aug 07, 2020
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GNPTAB c.344_345delCA (p.Thr115AsnfsX5) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 4.8e-05 in 251084 control chromosomes (gnomAD). This frequency is not significantly higher than expected for a pathogenic variant in GNPTAB causing Mucolipidosis (4.8e-05 vs 0.0022), allowing no conclusion about variant significance. c.344_345delCA has been reported in the literature in multiple individuals in compound heterozygous and homozygous states affected with Mucolipidosis II (Cathey_2010, Kollmann_2013). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submitters (evaluation after 2014) cite the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
PhyloP100
2.0
Mutation Taster
=0/200
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: rs281864954; hg19: chr12-102182345; API