19-12657482-G-T

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000528.4(MAN2B1):c.1383C>A(p.Tyr461*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000536 in 1,566,766 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000058 ( 0 hom. )

Consequence

MAN2B1
NM_000528.4 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:10

Conservation

PhyloP100: -0.928

Variant links:

Genes affected

MAN2B1 (HGNC:6826): (mannosidase alpha class 2B member 1) This gene encodes an enzyme that hydrolyzes terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides. Its activity is necessary for the catabolism of N-linked carbohydrates released during glycoprotein turnover and it is member of family 38 of glycosyl hydrolases. The full length protein is processed in two steps. First, a 49 aa leader sequence is cleaved off and the remainder of the protein is processed into 3 peptides of 70 kDa, 42 kDa (D) and 13/15 kDa (E). Next, the 70 kDa peptide is further processed into three peptides (A, B and C). The A, B and C peptides are disulfide-linked. Defects in this gene have been associated with lysosomal alpha-mannosidosis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2010]

MAN2B1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 19-12657482-G-T is Pathogenic according to our data. Variant chr19-12657482-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 281152.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MAN2B1	NM_000528.4 link	c.1383C>A	p.Tyr461*	stop_gained	Exon 11 of 24	ENST00000456935.7	NP_000519.2	O00754-1
MAN2B1	NM_001173498.2 link	c.1380C>A	p.Tyr460*	stop_gained	Exon 11 of 24		NP_001166969.1	O00754-2A8K6A7
MAN2B1	XM_005259913.3 link	c.1386C>A	p.Tyr462*	stop_gained	Exon 11 of 24		XP_005259970.1
MAN2B1	XM_047438841.1 link	c.282C>A	p.Tyr94*	stop_gained	Exon 4 of 17		XP_047294797.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAN2B1	ENST00000456935.7 link	c.1383C>A	p.Tyr461*	stop_gained	Exon 11 of 24	1	NM_000528.4	ENSP00000395473.2		O00754-1

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152210

Hom.:

Cov.:

show subpopulations

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:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000174

AC:

AN:

172302

Hom.:

AF XY:

0.0000107

AC XY:

AN XY:

93220

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000438

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000580

AC:

AN:

1414556

Hom.:

Cov.:

AF XY:

0.0000457

AC XY:

AN XY:

699720

show subpopulations

Gnomad4 AFR exome

AF:

0.0000308

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:

0.0000698

Gnomad4 OTH exome

AF:

0.0000855

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152210

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74364

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000756

ExAC

AF:

0.0000169

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:10

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase

Pathogenic:8

Apr 09, 2021

Molecular Genetics, Royal Melbourne Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature termination codon at position 461 in exon 11 (of 24) of MAN2B1 (p.(Tyr461*)). It is expected to result in nonsense mediated decay, in a gene where loss of function is an established mechanism of disease (ClinGen). The variant is present in a large population cohort at a frequency of 0.002% (3/172,302 alleles, 0 homozygotes in gnomAD v2.1), but this is based on three alleles in a region of poor coverage. It has been reported in multiple individuals with alpha-mannosidosis with a second pathogenic allele, and segregates with the condition in at least one family (PMID: 22161967, 26048034). Based on the classification scheme RMH Modified ACMG Guidelines v1.3.1, this variant is classified as PATHOGENIC. Following criteria are met: PVS1, PM3_Strong, PP1. -

Sep 05, 2021

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 25, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 08, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Dec 25, 2020

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: MAN2B1 c.1383C>A (p.Tyr461X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.7e-05 in 172302 control chromosomes. c.1383C>A has been reported in the literature in individuals affected with Alpha-Mannosidosis and subsequently cited by others (example, Riise Stensland_2012). These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. One submitter cites overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as pathogenic. -

Sep 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Tyr461*) in the MAN2B1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in MAN2B1 are known to be pathogenic (PMID: 9915946, 22161967). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individuals with alpha-mannosidosis (PMID: 22161967). ClinVar contains an entry for this variant (Variation ID: 281152). For these reasons, this variant has been classified as Pathogenic. -

Mar 27, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Apr 28, 2017

Illumina Laboratory Services, Illumina

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The MAN2B1 c.1383C>A (p.Tyr461Ter) variant is a stop-gained variant that has been reported in two studies in which it was found in a total of eight individuals with alpha-mannosidosis (including two sibling pairs) in a compound heterozygous state (Stensland et al 2012; Borgwardt et al. 2015). Control data are not available for this variant, which is reported at a frequency of 0.0001525 in the European (non-Finnish) population of the Exome Aggregation Consortium but this is based on one allele only in a region of poor sequence coverage. Due to the potential impact of stop-gained variants and the supporting evidence, the p.Tyr461Ter variant is classified as pathogenic for alpha-mannosidosis. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -

not provided

Pathogenic:2

Dec 11, 2015

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 07, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss-of-function is a known mechanism of disease; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 26048034, 22161967, 17979865) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.44

CADD

Uncertain

DANN

Uncertain

0.99

Eigen

Benign

-0.27

Eigen_PC

Benign

-0.66

FATHMM_MKL

Benign

0.35

Vest4

0.45

GERP RS

-5.9

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over