chr12-101764362-ATTTTC-A

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_024312.5(GNPTAB):c.2550_2554delGAAAA(p.Lys850AsnfsTer10) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,334 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: 0.0000075 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7O:1

Conservation

PhyloP100: 0.337

Publications

5 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

GNPTAB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 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 12-101764362-ATTTTC-A is Pathogenic according to our data. Variant chr12-101764362-ATTTTC-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 39055.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
GNPTAB	NM_024312.5 link	c.2550_2554delGAAAA	p.Lys850AsnfsTer10	frameshift_variant	Exon 13 of 21	ENST00000299314.12	NP_077288.2	Q3T906-1
GNPTAB	XM_011538731.3 link	c.2469_2473delGAAAA	p.Lys823AsnfsTer10	frameshift_variant	Exon 13 of 21		XP_011537033.1
GNPTAB	XM_006719593.4 link	c.2550_2554delGAAAA	p.Lys850AsnfsTer10	frameshift_variant	Exon 13 of 19		XP_006719656.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNPTAB	ENST00000299314.12 link	c.2550_2554delGAAAA	p.Lys850AsnfsTer10	frameshift_variant	Exon 13 of 21	1	NM_024312.5	ENSP00000299314.7		Q3T906-1

Frequencies

GnomAD3 genomes

AF:

0.00000660

AC:

AN:

151614

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000243

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000279

AC:

AN:

251182

AF XY:

0.0000368

show subpopulations

Gnomad AFR exome

AF:

0.0000615

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000352

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000753

AC:

AN:

1461720

Hom.:

AF XY:

0.0000110

AC XY:

AN XY:

727174

show subpopulations

African (AFR)

AF:

0.0000598

AC:

AN:

33468

American (AMR)

AF:

0.00

AC:

AN:

44718

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39694

South Asian (SAS)

AF:

0.0000580

AC:

AN:

86244

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53318

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00000360

AC:

AN:

1111986

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.493

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.00000660

AC:

AN:

151614

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

73994

show subpopulations

African (AFR)

AF:

0.0000243

AC:

AN:

41208

American (AMR)

AF:

0.00

AC:

AN:

15226

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5160

South Asian (SAS)

AF:

0.00

AC:

AN:

4802

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10498

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67946

Other (OTH)

AF:

0.00

AC:

AN:

2084

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.575

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:7Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II

Pathogenic:4

Mar 22, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 01, 2016

Diagnostics Division, CENTRE FOR DNA FINGERPRINTING AND DIAGNOSTICS

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

- -

Oct 02, 2017

Counsyl

Significance:Likely 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. -

Feb 29, 2024

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.Lys850Asnfs*10) 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 (rs281864996, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with mucolipidosis type II alpha/beta (PMID: 19634183). ClinVar contains an entry for this variant (Variation ID: 39055). For these reasons, this variant has been classified as Pathogenic. -

Mucolipidosis type II

Pathogenic:2Other:1

Nov 22, 2019

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.2550_2554delGAAAA (p.Lys850AsnfsX10) 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 2.8e-05 in 251182 control chromosomes (gnomAD). c.2550_2554delGAAAA has been reported in the literature in homozygous and compound heterozygous individuals affected with Mucolipidosis type 2 (Liu_2016, Tappino_2009). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two ClinVar submitters (evaluation after 2014) cite the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Apr 13, 2023

Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A heterozygous variation in exon 13 of the GNPTAB gene detected. The observed variant c.2550_2554del has not been reported in the 1000 genomes and MAF 0.0028% in the gnomAD databases. The in silico prediction of the variant are possibly damaging by PolyPhen-2 and damaging by SIFT and MutationTaster. In summary, the variant meets our criteria to be classified as pathogenic. -

GeneReviews

Significance:not provided

Review Status:no classification provided

Collection Method:literature only

- -

Mucolipidosis

Pathogenic:1

Department of Genetics and Endocrinology, Guangzhou Women and Children’s Medical Center

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

0.34

Mutation Taster

=4/196

disease causing (ClinVar)

(source)

Splicing

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over