NM_024312.5:c.771G>A

Variant names:

• chr12-101780152-C-T
• rs281865025
• NM_024312.5:c.771G>A

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PS3 PM2 PP3_Moderate PP5_Very_Strong

The NM_024312.5(GNPTAB):​c.771G>A​(p.Leu257Leu) variant causes a splice region, synonymous change. The variant allele was found at a frequency of 0.000013 in 1,612,570 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV001983660: Experimental evidence evaluating an impact on protein function demonstrated the variant results in the production of a minimal amount of functional enzyme (Steet_2005).". Synonymous variant affecting the same amino acid position (i.e. L257L) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000012 (0 hom.)
• Consequence: GNPTAB NM_024312.5 splice_region, synonymous
• Scores: Splicing: ADA: 0.9998
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 5.71
• Publications: 4 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]

RNA5SP368 (HGNC:43268): (RNA, 5S ribosomal pseudogene 368)

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV001983660: Experimental evidence evaluating an impact on protein function demonstrated the variant results in the production of a minimal amount of functional enzyme (Steet_2005).
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 12-101780152-C-T is Pathogenic according to our data. Variant chr12-101780152-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2761.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.771G>A	p.Leu257Leu	splice_region synonymous	Exon 7 of 21	NP_077288.2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GNPTAB	ENST00000299314.12	TSL:1 MANE Select	c.771G>A	p.Leu257Leu	splice_region synonymous	Exon 7 of 21	ENSP00000299314.7	Q3T906-1
	GNPTAB	ENST00000549940.5	TSL:1	c.771G>A	p.Leu257Leu	splice_region synonymous	Exon 7 of 11	ENSP00000449150.1	Q3T906-2
	GNPTAB	ENST00000552681.1	TSL:1	c.405G>A	p.Leu135Leu	synonymous	Exon 3 of 3	ENSP00000449217.1	H0YIE6

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152148 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.0000123 AC: 18 AN: 1460422 Hom.: 0 Cov.: 30 AF XY: 0.0000124 AC XY: 9 AN XY: 726664

African (AFR) AF: 0.00 AC: 0 AN: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39660

South Asian (SAS) AF: 0.00 AC: 0 AN: 86232

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53404

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.0000162 AC: 18 AN: 1110720

Other (OTH) AF: 0.00 AC: 0 AN: 60348

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152148 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74318

African (AFR) AF: 0.00 AC: 0 AN: 41412

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5208

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10604

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000441 AC: 3 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2088

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
1	-	-	Mucolipidosis (1)
1	-	-	Mucolipidosis III alpha/beta, atypical (1)
1	-	-	Mucolipidosis type II (1)
1	-	-	Pseudo-Hurler polydystrophy (1)
1	-	-	Pseudo-Hurler polydystrophy;C2673377:Mucolipidosis type II (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.15
CADD	Benign	22
DANN	Benign	0.91
PhyloP100		5.7
Mutation Taster		=7/93	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.99
SpliceAI score (max)		0.51		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.51		Position offset: 0

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

Other links and lift over

dbSNP: rs281865025; hg19: chr12-102173930;