rs864621976

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2PP3_Strong

The NM_000528.4(MAN2B1):​c.475G>A​(p.Asp159Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,204 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 Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Consequence

MAN2B1
NM_000528.4 missense

Scores

16
2
1

Clinical Significance

Uncertain significance criteria provided, single submitter U:3

Conservation

PhyloP100: 7.44

Publications

4 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: Likely_pathogenic. The variant received 6 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.98

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN2B1NM_000528.4 linkc.475G>A p.Asp159Asn missense_variant Exon 4 of 24 ENST00000456935.7 NP_000519.2
MAN2B1NM_001440570.1 linkc.475G>A p.Asp159Asn missense_variant Exon 4 of 24 NP_001427499.1
MAN2B1NM_001173498.2 linkc.475G>A p.Asp159Asn missense_variant Exon 4 of 24 NP_001166969.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN2B1ENST00000456935.7 linkc.475G>A p.Asp159Asn missense_variant Exon 4 of 24 1 NM_000528.4 ENSP00000395473.2
ENSG00000269590ENST00000597961.1 linkc.466G>A p.Asp156Asn missense_variant Exon 5 of 5 4 ENSP00000472710.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
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:
0.0000941
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74372
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5188
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.0000941
AC:
1
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.275
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Uncertain:2
Mar 28, 2018
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Jun 07, 2012
ClinVar Staff, National Center for Biotechnology Information (NCBI)
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:literature only

- -

not specified Uncertain:1
Apr 04, 2025
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: MAN2B1 c.475G>A (p.Asp159Asn) results in a conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant was absent in 250968 control chromosomes. c.475G>A has been reported in the literature in an individual affected with Alpha-Mannosidosis (Riise_2012). These data indicate that the variant may be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function, however, does not allow convincing conclusions about the variant effect (Kuokkanen_2011). The following publications have been ascertained in the context of this evaluation (PMID: 21505070, 22161967). ClinVar contains an entry for this variant (Variation ID: 208253). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.92
BayesDel_addAF
Pathogenic
0.17
D
BayesDel_noAF
Uncertain
0.0
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.86
D;.;.;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.93
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Pathogenic
0.98
D;D;D;D
M_CAP
Pathogenic
0.32
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Pathogenic
0.97
D
MutationAssessor
Pathogenic
3.8
H;H;.;.
PhyloP100
7.4
PrimateAI
Uncertain
0.69
T
PROVEAN
Pathogenic
-4.9
D;D;.;.
REVEL
Pathogenic
0.85
Sift
Pathogenic
0.0
D;D;.;.
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
D;.;.;.
Vest4
0.98
MutPred
0.94
Loss of catalytic residue at D159 (P = 0.17);Loss of catalytic residue at D159 (P = 0.17);.;.;
MVP
0.98
MPC
1.5
ClinPred
1.0
D
GERP RS
5.7
Varity_R
0.96
gMVP
0.96
Mutation Taster
=12/88
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.080
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: rs864621976; hg19: chr19-12775761; COSMIC: COSV54417360; COSMIC: COSV54417360; API