rs141212446

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 2P and 13B. PM1BP4_StrongBP6BS1BS2

The NM_000528.4(MAN2B1):​c.2260G>A​(p.Glu754Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00173 in 1,613,084 control chromosomes in the GnomAD database, including 7 homozygotes. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0013 ( 0 hom., cov: 30)
Exomes 𝑓: 0.0018 ( 7 hom. )

Consequence

MAN2B1
NM_000528.4 missense

Scores

1
18

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:4B:6

Conservation

PhyloP100: 0.249

Publications

5 publications found
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 Gene-Disease associations (from GenCC):
  • alpha-mannosidosis
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Genomics England PanelApp, Myriad Women’s Health, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -11 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000528.4
BP4
Computational evidence support a benign effect (MetaRNN=0.024946094).
BP6
Variant 19-12649920-C-T is Benign according to our data. Variant chr19-12649920-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 328262.
BS1
Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.00129 (196/151972) while in subpopulation NFE AF = 0.00234 (159/67946). AF 95% confidence interval is 0.00204. There are 0 homozygotes in GnomAd4. There are 91 alleles in the male GnomAd4 subpopulation. Median coverage is 30. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 7 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN2B1NM_000528.4 linkc.2260G>A p.Glu754Lys missense_variant Exon 18 of 24 ENST00000456935.7 NP_000519.2 O00754-1
MAN2B1NM_001440570.1 linkc.2263G>A p.Glu755Lys missense_variant Exon 18 of 24 NP_001427499.1
MAN2B1NM_001173498.2 linkc.2257G>A p.Glu753Lys missense_variant Exon 18 of 24 NP_001166969.1 O00754-2A8K6A7
MAN2B1XM_047438841.1 linkc.1159G>A p.Glu387Lys missense_variant Exon 11 of 17 XP_047294797.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN2B1ENST00000456935.7 linkc.2260G>A p.Glu754Lys missense_variant Exon 18 of 24 1 NM_000528.4 ENSP00000395473.2 O00754-1
MAN2B1ENST00000221363.9 linkc.2257G>A p.Glu753Lys missense_variant Exon 18 of 24 1 ENSP00000221363.4 O00754-2
MAN2B1ENST00000466794.5 linkn.2850G>A non_coding_transcript_exon_variant Exon 16 of 22 2

Frequencies

GnomAD3 genomes
AF:
0.00129
AC:
196
AN:
151856
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.000315
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000525
Gnomad ASJ
AF:
0.00346
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.000283
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00234
Gnomad OTH
AF:
0.000482
GnomAD2 exomes
AF:
0.00123
AC:
309
AN:
251484
AF XY:
0.00115
show subpopulations
Gnomad AFR exome
AF:
0.000369
Gnomad AMR exome
AF:
0.000896
Gnomad ASJ exome
AF:
0.00317
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.000231
Gnomad NFE exome
AF:
0.00192
Gnomad OTH exome
AF:
0.000814
GnomAD4 exome
AF:
0.00177
AC:
2592
AN:
1461112
Hom.:
7
Cov.:
34
AF XY:
0.00175
AC XY:
1274
AN XY:
726876
show subpopulations
African (AFR)
AF:
0.000419
AC:
14
AN:
33452
American (AMR)
AF:
0.00105
AC:
47
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00222
AC:
58
AN:
26128
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.000255
AC:
22
AN:
86228
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53396
Middle Eastern (MID)
AF:
0.000362
AC:
2
AN:
5528
European-Non Finnish (NFE)
AF:
0.00212
AC:
2355
AN:
1111618
Other (OTH)
AF:
0.00143
AC:
86
AN:
60338
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
128
255
383
510
638
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
84
168
252
336
420
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00129
AC:
196
AN:
151972
Hom.:
0
Cov.:
30
AF XY:
0.00123
AC XY:
91
AN XY:
74272
show subpopulations
African (AFR)
AF:
0.000314
AC:
13
AN:
41422
American (AMR)
AF:
0.000524
AC:
8
AN:
15266
Ashkenazi Jewish (ASJ)
AF:
0.00346
AC:
12
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5168
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.000283
AC:
3
AN:
10588
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.00234
AC:
159
AN:
67946
Other (OTH)
AF:
0.000477
AC:
1
AN:
2098
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.492
Heterozygous variant carriers
0
9
17
26
34
43
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
4
8
12
16
20
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00187
Hom.:
0
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.00140
AC:
12
ExAC
AF:
0.00102
AC:
124
EpiCase
AF:
0.00164
EpiControl
AF:
0.00160

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:4Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Uncertain:2Benign:3
Jan 21, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 22, 2021
Department of Pathology and Laboratory Medicine, Sinai Health System
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:research

- -

Jan 13, 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. -

Nov 11, 2019
Natera, Inc.
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Sep 05, 2021
Genome-Nilou Lab
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:2Benign:1
Feb 01, 2025
CeGaT Center for Human Genetics Tuebingen
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

MAN2B1: BP4 -

Jun 27, 2017
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

May 16, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

BS1 -

not specified Benign:1
Dec 07, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MAN2B1 c.2260G>A (p.Glu754Lys) results in a conservative amino acid change located in the Glycosyl hydrolase family 38, C-terminal (IPR011682) of the encoded protein sequence. Four of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.0012 in 251484 control chromosomes, predominantly at a frequency of 0.0019 within the Non-Finnish European subpopulation in the gnomAD database, including 2 homozygotes. The observed variant frequency within Non-Finnish European control individuals in the gnomAD database is approximately 1.2 fold of the estimated maximal expected allele frequency for a pathogenic variant in MAN2B1 causing Alpha-Mannosidosis phenotype (0.0016), strongly suggesting that the variant is a benign polymorphism found primarily in populations of Non-Finnish European origin. To our knowledge, no occurrence of c.2260G>A in individuals affected with Alpha-Mannosidosis and no experimental evidence demonstrating its impact on protein function have been reported. Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified as benign/likely benign (n=4) and VUS (n=3). Based on the evidence outlined above, the variant was classified as likely benign. -

MAN2B1-related disorder Benign:1
Jul 11, 2023
PreventionGenetics, part of Exact Sciences
Significance:Likely benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.10
BayesDel_addAF
Benign
-0.44
T
BayesDel_noAF
Benign
-0.42
CADD
Benign
15
DANN
Benign
0.33
DEOGEN2
Benign
0.17
T;.
Eigen
Benign
-0.97
Eigen_PC
Benign
-0.83
FATHMM_MKL
Benign
0.72
D
LIST_S2
Uncertain
0.89
D;D
M_CAP
Benign
0.026
D
MetaRNN
Benign
0.025
T;T
MetaSVM
Benign
-0.86
T
MutationAssessor
Benign
-0.39
N;.
PhyloP100
0.25
PrimateAI
Benign
0.31
T
PROVEAN
Benign
0.49
N;N
REVEL
Benign
0.20
Sift
Benign
1.0
T;T
Sift4G
Benign
1.0
T;T
Polyphen
0.020
B;.
Vest4
0.30
MVP
0.53
MPC
0.27
ClinPred
0.0013
T
GERP RS
-1.3
Varity_R
0.055
gMVP
0.57
Mutation Taster
=98/2
polymorphism

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

Other links and lift over

dbSNP: rs141212446; hg19: chr19-12760734; COSMIC: COSV106370724; COSMIC: COSV106370724; API