12-101745531-AG-A

Variant names:

• chr12-101745531-AG-A
• rs370646056
• NM_024312.5:c.*1632delC

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BS1_Supporting BS2

The NM_024312.5(GNPTAB):​c.*1632delC variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00312 in 152,360 control chromosomes in the GnomAD database, including 6 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.0031 (6 hom., cov: 33)
  • Failed GnomAD Quality Control
• Consequence: GNPTAB NM_024312.5 3_prime_UTR
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: -0.137
• 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: Likely_benign. The variant received -5 ACMG points.

• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00312 (475/152360) while in subpopulation AFR AF = 0.0104 (433/41598). AF 95% confidence interval is 0.0096. There are 6 homozygotes in GnomAd4. There are 229 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting
• BS2: High Homozygotes in GnomAd4 at 6 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GNPTAB	NM_024312.5	c.*1632delC		3_prime_UTR_variant	Exon 21 of 21	ENST00000299314.12	NP_077288.2
GNPTAB	XM_011538731.3	c.*1632delC		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.*1632delC		3_prime_UTR_variant	Exon 21 of 21	1	NM_024312.5	ENSP00000299314.7

Frequencies

GnomAD3 genomes AF: 0.00303 AC: 461 AN: 152244 Hom.: 1 Cov.: 33

Gnomad AFR AF: 0.0104

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000916

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000769

Gnomad SAS AF: 0.000414

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00239

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

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AC: 0 AN: 0

South Asian (SAS) AC: 0 AN: 0

European-Finnish (FIN) AC: 0 AN: 0

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AC: 0 AN: 0

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.00312 AC: 475 AN: 152360 Hom.: 6 Cov.: 33 AF XY: 0.00307 AC XY: 229 AN XY: 74522

African (AFR) AF: 0.0104 AC: 433 AN: 41598

American (AMR) AF: 0.000914 AC: 14 AN: 15310

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.000771 AC: 4 AN: 5190

South Asian (SAS) AF: 0.000207 AC: 1 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

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

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68024

Other (OTH) AF: 0.00947 AC: 20 AN: 2112

Alfa AF: 0.000215 Hom.: 0

Bravo AF: 0.00334

Asia WGS AF: 0.0200 AC: 70 AN: 3478

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, single submitter

Submissions by phenotype

Pseudo-Hurler polydystrophy Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mucolipidosis type II Uncertain:1

Jun 14, 2016

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.14

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: rs370646056; hg19: chr12-102139309;