12-101761306-G-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PM5PP3_Moderate

The NM_024312.5(GNPTAB):c.2956C>A(p.Arg986Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,728 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R986P) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

GNPTAB
NM_024312.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.71

Publications

8 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: Likely_pathogenic. The variant received 8 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_024312.5

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr12-101761305-C-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 1324494.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.886

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
GNPTAB	NM_024312.5 link	c.2956C>A	p.Arg986Ser	missense_variant	Exon 15 of 21	ENST00000299314.12	NP_077288.2
GNPTAB	XM_011538731.3 link	c.2875C>A	p.Arg959Ser	missense_variant	Exon 15 of 21		XP_011537033.1
GNPTAB	XM_006719593.4 link	c.2956C>A	p.Arg986Ser	missense_variant	Exon 15 of 19		XP_006719656.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNPTAB	ENST00000299314.12 link	c.2956C>A	p.Arg986Ser	missense_variant	Exon 15 of 21	1	NM_024312.5	ENSP00000299314.7

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000753

AC:

AN:

1461728

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727168

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26134

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53302

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000989

AC:

AN:

1111972

Other (OTH)

AF:

0.00

AC:

AN:

60392

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000000000810463), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.389

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

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Mucolipidosis type II

Uncertain:1

May 15, 2019

Ege University Pediatric Genetics, Ege University

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.45

BayesDel_noAF

Pathogenic

0.40

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.96

Eigen

Pathogenic

0.94

Eigen_PC

Pathogenic

0.92

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Uncertain

0.96

M_CAP

Uncertain

0.17

MetaRNN

Pathogenic

0.89

MetaSVM

Uncertain

0.70

MutationAssessor

Uncertain

2.5

PhyloP100

7.7

PrimateAI

Pathogenic

0.82

PROVEAN

Pathogenic

-5.6

REVEL

Pathogenic

0.82

Sift

Pathogenic

0.0

Sift4G

Uncertain

0.011

Polyphen

1.0

Vest4

0.91

MutPred

0.47

Gain of ubiquitination at K984 (P = 0.0376);

MVP

0.92

MPC

0.88

ClinPred

1.0

GERP RS

5.9

Varity_R

0.99

gMVP

0.97

Mutation Taster

=7/93

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.20

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.20

Position offset: 4

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over