rs281865025

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 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 (★★).

Frequency

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

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 splice_region, synonymous

Scores

Splicing: ADA: 0.9998

Clinical Significance

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

Conservation

PhyloP100: 5.71

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 links:

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

RNA5SP368 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius 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 id is 2761.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101780152-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNPTAB	NM_024312.5 link	c.771G>A	p.Leu257Leu	splice_region_variant, synonymous_variant	Exon 7 of 21	ENST00000299314.12	NP_077288.2	Q3T906-1
GNPTAB	XM_011538731.3 link	c.690G>A	p.Leu230Leu	splice_region_variant, synonymous_variant	Exon 7 of 21		XP_011537033.1
GNPTAB	XM_006719593.4 link	c.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	UniProt
GNPTAB	ENST00000299314.12 link	c.771G>A	p.Leu257Leu	splice_region_variant, synonymous_variant	Exon 7 of 21	1	NM_024312.5	ENSP00000299314.7	Q3T906-1
GNPTAB	ENST00000549940.5 link	c.771G>A	p.Leu257Leu	splice_region_variant, synonymous_variant	Exon 7 of 11	1		ENSP00000449150.1	Q3T906-2
GNPTAB	ENST00000552681.1 link	c.405G>A	p.Leu135Leu	synonymous_variant	Exon 3 of 3	1		ENSP00000449217.1	H0YIE6
RNA5SP368	ENST00000364298.1 link	n.*223C>T		downstream_gene_variant		6

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152148

Hom.:

Cov.:

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:

AN:

1460422

Hom.:

Cov.:

AF XY:

0.0000124

AC XY:

AN XY:

726664

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000162

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152148

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74318

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000441

Gnomad4 OTH

AF:

0.00

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

DANN

Benign

0.91

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over