rs281865025

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM2PP3_ModeratePP5_Very_Strong

The NM_024312.5(GNPTAB):​c.771G>A​(p.Leu257Leu) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000013 in 1,612,570 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. L257L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 splice_region, synonymous

Scores

2
Splicing: ADA: 0.9998
2

Clinical Significance

Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 5.71

Publications

4 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]
RNA5SP368 (HGNC:43268): (RNA, 5S ribosomal pseudogene 368)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
PP5
Variant 12-101780152-C-T is Pathogenic according to our data. Variant chr12-101780152-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2761.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.771G>A p.Leu257Leu splice_region_variant, synonymous_variant Exon 7 of 21 ENST00000299314.12 NP_077288.2
GNPTABXM_011538731.3 linkc.690G>A p.Leu230Leu splice_region_variant, synonymous_variant Exon 7 of 21 XP_011537033.1
GNPTABXM_006719593.4 linkc.771G>A p.Leu257Leu splice_region_variant, synonymous_variant Exon 7 of 19 XP_006719656.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GNPTABENST00000299314.12 linkc.771G>A p.Leu257Leu splice_region_variant, synonymous_variant Exon 7 of 21 1 NM_024312.5 ENSP00000299314.7
GNPTABENST00000549940.5 linkc.771G>A p.Leu257Leu splice_region_variant, synonymous_variant Exon 7 of 11 1 ENSP00000449150.1
GNPTABENST00000552681.1 linkc.405G>A p.Leu135Leu synonymous_variant Exon 3 of 3 1 ENSP00000449217.1
RNA5SP368ENST00000364298.1 linkn.*223C>T downstream_gene_variant 6

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152148
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1460422
Hom.:
0
Cov.:
30
AF XY:
0.0000124
AC XY:
9
AN XY:
726664
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33452
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39660
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86232
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53404
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5764
European-Non Finnish (NFE)
AF:
0.0000162
AC:
18
AN:
1110720
Other (OTH)
AF:
0.00
AC:
0
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
1
2
3
4
5
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:
152148
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74318
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41412
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5208
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10604
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68028
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.442
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:
0.00000756

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Pseudo-Hurler polydystrophy Pathogenic:1
May 10, 2012
GeneReviews
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:curation

- -

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II Pathogenic:1
Dec 02, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change affects codon 257 of the GNPTAB mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the GNPTAB protein. RNA analysis indicates that this variant induces altered splicing and likely results in a shortened protein product. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with mucolipidosis type III (PMID: 15633164). ClinVar contains an entry for this variant (Variation ID: 2761). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this variant results in skipping of exon 7, but is expected to preserve the integrity of the reading-frame (PMID: 15633164). In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Mucolipidosis III alpha/beta, atypical Pathogenic:1
Feb 01, 2005
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Mucolipidosis Pathogenic:1
Sep 13, 2021
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: GNPTAB c.771G>A (p.Leu257Leu) alters a conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: Three predict the variant weakens a 5' donor site and one predicts the variant abolishes a 5' splicing donor site. Experimental evidence supports these predictions indicating that this variant affects mRNA splicing leading to the skipping of exon 7 (Steet_2005). The variant was absent in 251190 control chromosomes (gnomAD). c.771G>A has been reported in the literature in a homozygous individual affected with Mucolipidosis (Steet_2005). These data indicate that the variant may be associated with disease. Experimental evidence evaluating an impact on protein function demonstrated the variant results in the production of a minimal amount of functional enzyme (Steet_2005). A ClinVar submitter (evaluation after 2014) cites the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Mucolipidosis type II Pathogenic:1
Jul 21, 2020
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.15
CADD
Benign
22
DANN
Benign
0.91
PhyloP100
5.7
Mutation Taster
=7/93
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.51
Details are displayed if max score is > 0.2
DS_DL_spliceai
0.51
Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs281865025; hg19: chr12-102173930; API