12-101780173-A-AT

Position:

chr12-101780173-A-AT

Variant summary

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

The NM_024312.5(GNPTAB):c.749_750insA(p.Asn250LysfsTer5) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000062 in 1,613,594 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3O:1

Conservation

PhyloP100: 0.119

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 12-101780173-A-AT is Pathogenic according to our data. Variant chr12-101780173-A-AT is described in ClinVar as [Likely_pathogenic]. Clinvar id is 39087.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
GNPTAB	NM_024312.5 linkuse as main transcript	c.749_750insA	p.Asn250LysfsTer5	frameshift_variant	7/21	ENST00000299314.12
GNPTAB	XM_006719593.4 linkuse as main transcript	c.749_750insA	p.Asn250LysfsTer5	frameshift_variant	7/19
GNPTAB	XM_011538731.3 linkuse as main transcript	c.668_669insA	p.Asn223LysfsTer5	frameshift_variant	7/21

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GNPTAB	ENST00000299314.12 linkuse as main transcript	c.749_750insA	p.Asn250LysfsTer5	frameshift_variant	7/21	1	NM_024312.5	P1	Q3T906-1
GNPTAB	ENST00000549940.5 linkuse as main transcript	c.749_750insA	p.Asn250LysfsTer5	frameshift_variant	7/11	1			Q3T906-2
GNPTAB	ENST00000552681.1 linkuse as main transcript	c.383_384insA	p.Asn128LysfsTer5	frameshift_variant	3/3	1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152102

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:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251238

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135808

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000616

AC:

AN:

1461492

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727090

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:

0.00000810

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152102

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74292

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:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Dec 21, 2023

This sequence change creates a premature translational stop signal (p.Asn250Lysfs*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 (rs281864964, gnomAD 0.0009%). This premature translational stop signal has been observed in individual(s) with GNPTAB-related conditions (PMID: 19634183). ClinVar contains an entry for this variant (Variation ID: 39087). For these reasons, this variant has been classified as Pathogenic. -

Mucolipidosis

Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Oct 28, 2022

Variant summary: GNPTAB c.749dupA (p.Asn250LysfsX5) 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 4e-06 in 251438 control chromosomes. c.749dupA has been reported in the literature in compound heterozygosity with a known pathogenic variant in an individual affected with Mucolipidosis type II (Tappino_2009), providing evidence for pathogenicity. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. One clinical diagnostic laboratory has submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation, classifying the variant as pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

May 22, 2014

- -

Mucolipidosis type II

Other:1

not provided, no classification provided

literature only

GeneReviews

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

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