rs281864974

Variant names:

• chr12-101768162-T-C
• rs281864974
• NM_024312.5:c.1285-2A>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PVS1 PM2

The NM_024312.5(GNPTAB):​c.1285-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as not provided (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: GNPTAB NM_024312.5 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 7.24
• Publications: 2 publications found

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: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, PanelApp Australia, Ambry Genetics, Orphanet
• mucolipidosis type III, alpha/beta

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Genomics England PanelApp, Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_024312.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNPTAB	NM_024312.5	MANE Select	c.1285-2A>G		splice_acceptor intron	N/A	NP_077288.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNPTAB	ENST00000299314.12	TSL:1 MANE Select	c.1285-2A>G		splice_acceptor intron	N/A	ENSP00000299314.7	Q3T906-1
	GNPTAB	ENST00000549940.5	TSL:1	c.1285-2A>G		splice_acceptor intron	N/A	ENSP00000449150.1	Q3T906-2
	GNPTAB	ENST00000917136.1		c.1306-2A>G		splice_acceptor intron	N/A	ENSP00000587195.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

ClinVar

ClinVar submissions as Germline

Significance: not provided

Revision: no classification provided

Pathogenic	VUS	Benign	Condition
-	-	-	Pseudo-Hurler polydystrophy (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Uncertain	0.040
CADD	Pathogenic	28
DANN	Uncertain	0.98
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.83
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		7.2
GERP RS		4.5
Mutation Taster		=4/96	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.99		Position offset: -2

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

Other links and lift over

dbSNP: rs281864974; hg19: chr12-102161940;