19-12652193-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_000528.4(MAN2B1):​c.2006C>G​(p.Pro669Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000109 in 1,461,866 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P669L) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000011 ( 0 hom. )

Consequence

MAN2B1
NM_000528.4 missense

Scores

5
7
7

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.87

Publications

13 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: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.822

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN2B1NM_000528.4 linkc.2006C>G p.Pro669Arg missense_variant Exon 16 of 24 ENST00000456935.7 NP_000519.2 O00754-1
MAN2B1NM_001440570.1 linkc.2009C>G p.Pro670Arg missense_variant Exon 16 of 24 NP_001427499.1
MAN2B1NM_001173498.2 linkc.2003C>G p.Pro668Arg missense_variant Exon 16 of 24 NP_001166969.1 O00754-2A8K6A7
MAN2B1XM_047438841.1 linkc.905C>G p.Pro302Arg missense_variant Exon 9 of 17 XP_047294797.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN2B1ENST00000456935.7 linkc.2006C>G p.Pro669Arg missense_variant Exon 16 of 24 1 NM_000528.4 ENSP00000395473.2 O00754-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251466
AF XY:
0.00000736
show subpopulations
Gnomad AFR exome
AF:
0.0000616
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000879
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000109
AC:
16
AN:
1461866
Hom.:
0
Cov.:
32
AF XY:
0.00000963
AC XY:
7
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86248
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000108
AC:
12
AN:
1111996
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.472
Heterozygous variant carriers
0
2
3
5
6
8
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome 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
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
14
Bravo
AF:
0.00000378

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Uncertain:1
Oct 03, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces proline, which is neutral and non-polar, with arginine, which is basic and polar, at codon 669 of the MAN2B1 protein (p.Pro669Arg). This variant is present in population databases (no rsID available, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with MAN2B1-related conditions. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on MAN2B1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.41
BayesDel_addAF
Benign
-0.011
T
BayesDel_noAF
Uncertain
-0.070
CADD
Pathogenic
26
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.58
D;.
Eigen
Pathogenic
0.68
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Benign
0.77
T;T
M_CAP
Benign
0.060
D
MetaRNN
Pathogenic
0.82
D;D
MetaSVM
Uncertain
0.46
D
MutationAssessor
Pathogenic
3.1
M;.
PhyloP100
8.9
PrimateAI
Benign
0.35
T
PROVEAN
Pathogenic
-4.7
D;D
REVEL
Uncertain
0.61
Sift
Benign
0.23
T;T
Sift4G
Benign
0.32
T;T
Polyphen
1.0
D;.
Vest4
0.74
MutPred
0.54
Gain of MoRF binding (P = 0.0045);.;
MVP
0.93
MPC
0.89
ClinPred
0.96
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.59
gMVP
0.67
Mutation Taster
=77/23
polymorphism

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

Publications

Other links and lift over

dbSNP: rs75029862; hg19: chr19-12763007; API