12-101746518-C-A

Variant names:

• chr12-101746518-C-A
• rs182829610
• NM_024312.5:c.*646G>T

Variant summary

Our verdict is Benign. The variant received -8 ACMG points: 0P and 8B. BP4_Strong BS2

The NM_024312.5(GNPTAB):​c.*646G>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00289 in 152,282 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0029 (2 hom., cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GNPTAB NM_024312.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 0.578
• Publications: 0 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: 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

ACMG classification

Our verdict: Benign. The variant received -8 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.81).
• BS2: High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNPTAB	NM_024312.5	c.*646G>T		3_prime_UTR_variant	Exon 21 of 21	ENST00000299314.12	NP_077288.2
GNPTAB	XM_011538731.3	c.*646G>T		3_prime_UTR_variant	Exon 21 of 21		XP_011537033.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GNPTAB	ENST00000299314.12	c.*646G>T		3_prime_UTR_variant	Exon 21 of 21	1	NM_024312.5	ENSP00000299314.7

Frequencies

GnomAD3 genomes AF: 0.00289 AC: 440 AN: 152164 Hom.: 2 Cov.: 33

Gnomad AFR AF: 0.000821

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00190

Gnomad ASJ AF: 0.00259

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00103

Gnomad FIN AF: 0.00273

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00487

Gnomad OTH AF: 0.00143

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 132 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 80

African (AFR) AC: 0 AN: 0

American (AMR) AF: 0.00 AC: 0 AN: 6

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AF: 0.00 AC: 0 AN: 2

South Asian (SAS) AF: 0.00 AC: 0 AN: 4

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 4

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 114

Other (OTH) AF: 0.00 AC: 0 AN: 2

GnomAD4 genome AF: 0.00289 AC: 440 AN: 152282 Hom.: 2 Cov.: 33 AF XY: 0.00275 AC XY: 205 AN XY: 74466

African (AFR) AF: 0.000819 AC: 34 AN: 41530

American (AMR) AF: 0.00189 AC: 29 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00259 AC: 9 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00103 AC: 5 AN: 4834

European-Finnish (FIN) AF: 0.00273 AC: 29 AN: 10608

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00487 AC: 331 AN: 68022

Other (OTH) AF: 0.00142 AC: 3 AN: 2116

Alfa AF: 0.00461 Hom.: 0

Bravo AF: 0.00285

Asia WGS AF: 0.000577 AC: 2 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Pseudo-Hurler polydystrophy Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Mucolipidosis type II Uncertain:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.81
CADD	Benign	6.6
DANN	Benign	0.49
PhyloP100		0.58

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

Other links and lift over

dbSNP: rs182829610; hg19: chr12-102140296;