chr12-101770182-G-A

Position:

chr12-101770182-G-A

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_024312.5(GNPTAB):c.1123C>T(p.Arg375*) variant causes a stop gained change. The variant allele was found at a frequency of 0.0000421 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000079 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000038 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 stop_gained

Scores

Clinical Significance

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

Conservation

PhyloP100: 5.15

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:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 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 12-101770182-G-A is Pathogenic according to our data. Variant chr12-101770182-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 39022.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr12-101770182-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNPTAB	NM_024312.5 linkuse as main transcript	c.1123C>T	p.Arg375*	stop_gained	10/21	ENST00000299314.12	NP_077288.2	Q3T906-1
GNPTAB	XM_011538731.3 linkuse as main transcript	c.1042C>T	p.Arg348*	stop_gained	10/21		XP_011537033.1
GNPTAB	XM_006719593.4 linkuse as main transcript	c.1123C>T	p.Arg375*	stop_gained	10/19		XP_006719656.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNPTAB	ENST00000299314.12 linkuse as main transcript	c.1123C>T	p.Arg375*	stop_gained	10/21	1	NM_024312.5	ENSP00000299314.7		Q3T906-1
GNPTAB	ENST00000549940.5 linkuse as main transcript	c.1123C>T	p.Arg375*	stop_gained	10/11	1		ENSP00000449150.1		Q3T906-2

Frequencies

GnomAD3 genomes

AF:

0.0000789

AC:

AN:

152106

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:

0.000162

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.0000398

AC:

AN:

251376

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135862

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000383

AC:

AN:

1461826

Hom.:

Cov.:

AF XY:

0.0000399

AC XY:

AN XY:

727230

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:

0.0000116

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.0000459

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000789

AC:

AN:

152106

Hom.:

Cov.:

AF XY:

0.0000673

AC XY:

AN XY:

74294

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:

0.000162

Gnomad4 OTH

AF:

0.000478

Alfa

AF:

0.000474

Hom.:

Bravo

AF:

0.0000189

ExAC

AF:

0.0000576

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Mucolipidosis type II

Pathogenic:2Other:1

not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 15, 2017	Variant summary: The GNPTAB c.1123C>T (p.Arg375X) variant results in a premature termination codon, predicted to cause a truncated or absent GNPTAB 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 (e.g. c.1581delC, p.Cys528fsX19; c.2693delA, p.Lys898fsX13). One in silico tool predicts a damaging outcome for this variant. This variant was found in 7/121384 control chromosomes at a frequency of 0.0000577, which does not exceed the estimated maximal expected allele frequency of a pathogenic GNPTAB variant (0.0022361). The variant has been reported in multiple affected individuals in the literature both as homozygote and compound heterozygotes, and was shown in an in vitro study to produce a much smaller protein of about 50kDa in size, consistent with the synthesis of a severely truncated protein product that is unlikely to have retained any functional activity (Tappino_2009). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as pathogenic. Taken together, this variant is classified as pathogenic. -

Pseudo-Hurler polydystrophy

Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Counsyl

Sep 28, 2017

- -

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Dec 04, 2023

This sequence change creates a premature translational stop signal (p.Arg375*) 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 (rs397507447, gnomAD 0.02%). This premature translational stop signal has been observed in individuals with mucolipidosis type II and type III (PMID: 19617216). ClinVar contains an entry for this variant (Variation ID: 39022). For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Feb 20, 2013

- -

GNPTAB-related disorder

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Apr 21, 2022

The GNPTAB c.1123C>T (p.Arg375Ter) nonsense variant results in the substitution of arginine at amino acid position 375 with a stop codon. Loss of normal protein function through either protein truncation or nonsense mediated decay is expected. Across a selection of the literature, the c.1123C>T variant has been reported in a compound heterozygous state in at least six individuals with biochemically confirmed mucolipidosis II (ML II) or mucolipidosos III alpha/beta, and in a homozygous state in at least one individual with ML II (Tappino et al. 2009; Cathey et al. 2010; Cury et al. 2013; Retterer et al. 2016). The c.1123C>T variant is reported at a frequency of 0.0001705 in the European (non-Finnish) population of the Genome Aggregation Database (version 2.1.1). Based on the available evidence, the c.1123C>T (p.Arg375Ter) variant is classified as pathogenic for GNPTAB-related disorders. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.36

BayesDel_noAF

Pathogenic

0.54

CADD

Pathogenic

DANN

Uncertain

1.0

Eigen

Pathogenic

0.97

Eigen_PC

Pathogenic

0.84

FATHMM_MKL

Uncertain

0.83

Vest4

0.92

GERP RS

5.9

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.39

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.39

Position offset: -29

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