rs281864970

Positions:

• chr12-101770518-C-A
• chr12-101770518-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_024312.5(GNPTAB):​c.1001G>T​(p.Arg334Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,664 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R334P) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GNPTAB NM_024312.5 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.48

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]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PM1: In a helix (size 11) in uniprot entity GNPTA_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) 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 chr12-101770518-C-G is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 12-101770518-C-A is Pathogenic according to our data. Variant chr12-101770518-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 39019.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr12-101770518-C-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GNPTAB	NM_024312.5	c.1001G>T	p.Arg334Leu	missense_variant	9/21	ENST00000299314.12	NP_077288.2
GNPTAB	XM_011538731.3	c.920G>T	p.Arg307Leu	missense_variant	9/21		XP_011537033.1
GNPTAB	XM_006719593.4	c.1001G>T	p.Arg334Leu	missense_variant	9/19		XP_006719656.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GNPTAB	ENST00000299314.12	c.1001G>T	p.Arg334Leu	missense_variant	9/21	1	NM_024312.5	ENSP00000299314	P1
GNPTAB	ENST00000549940.5	c.1001G>T	p.Arg334Leu	missense_variant	9/11	1		ENSP00000449150

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460664 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726778

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: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 12, 2019

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. This variant disrupts the p.Arg334 amino acid residue in GNPTAB. Other variant(s) that disrupt this residue have been observed in individuals with GNPTAB-related conditions (PMID: 29872134, 19617216), which suggests that this may be a clinically significant amino acid residue. This variant has been reported to affect GNPTAB protein function (PMID: 25505245). This variant has been observed in individual(s) with GNPTAB-related conditions (PMID: 19197337). ClinVar contains an entry for this variant (Variation ID: 39019). This variant is not present in population databases (ExAC no frequency). This sequence change replaces arginine with leucine at codon 334 of the GNPTAB protein (p.Arg334Leu). The arginine residue is highly conserved and there is a moderate physicochemical difference between arginine and leucine. -

Mucolipidosis type II Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	D;.
Eigen	Uncertain	0.58
Eigen_PC	Uncertain	0.42
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.32	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.4	M;M
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-6.7	D;D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;D
Vest4		0.93
MutPred		0.91		Loss of MoRF binding (P = 0.0133);Loss of MoRF binding (P = 0.0133);
MVP		0.95
MPC		0.93
ClinPred		1.0	D
GERP RS		4.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.94
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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

Other links and lift over

dbSNP: rs281864970; hg19: chr12-102164296;