19-12646664-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_000528.4(MAN2B1):​c.2992C>T​(p.Arg998Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000248 in 1,613,952 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R998H) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 31)
Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

MAN2B1
NM_000528.4 missense

Scores

14
2
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 7.87

Publications

1 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 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.969
PP5
Variant 19-12646664-G-A is Pathogenic according to our data. Variant chr19-12646664-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 2146799.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN2B1NM_000528.4 linkc.2992C>T p.Arg998Cys missense_variant Exon 24 of 24 ENST00000456935.7 NP_000519.2 O00754-1
MAN2B1NM_001440570.1 linkc.2995C>T p.Arg999Cys missense_variant Exon 24 of 24 NP_001427499.1
MAN2B1NM_001173498.2 linkc.2989C>T p.Arg997Cys missense_variant Exon 24 of 24 NP_001166969.1 O00754-2A8K6A7
MAN2B1XM_047438841.1 linkc.1891C>T p.Arg631Cys missense_variant Exon 17 of 17 XP_047294797.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN2B1ENST00000456935.7 linkc.2992C>T p.Arg998Cys missense_variant Exon 24 of 24 1 NM_000528.4 ENSP00000395473.2 O00754-1
ENSG00000269242ENST00000597692.1 linkn.550C>T non_coding_transcript_exon_variant Exon 4 of 5 2 ENSP00000470240.1 M0QZ24

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
152096
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.0000942
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251482
AF XY:
0.0000441
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000578
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.0000462
Gnomad NFE exome
AF:
0.0000527
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.0000239
AC:
35
AN:
1461856
Hom.:
0
Cov.:
31
AF XY:
0.0000234
AC XY:
17
AN XY:
727234
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.0000894
AC:
4
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.000150
AC:
8
AN:
53420
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000171
AC:
19
AN:
1111978
Other (OTH)
AF:
0.0000497
AC:
3
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
3
6
8
11
14
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
AF:
0.0000329
AC:
5
AN:
152096
Hom.:
0
Cov.:
31
AF XY:
0.0000673
AC XY:
5
AN XY:
74286
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41414
American (AMR)
AF:
0.000131
AC:
2
AN:
15270
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3466
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5184
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4818
European-Finnish (FIN)
AF:
0.0000942
AC:
1
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68016
Other (OTH)
AF:
0.00
AC:
0
AN:
2084
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.515
Heterozygous variant carriers
0
1
2
2
3
4
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
Alfa
AF:
0.0000282
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000330
AC:
4

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Pathogenic:1Uncertain:1
Aug 16, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 998 of the MAN2B1 protein (p.Arg998Cys). This variant is present in population databases (rs758755293, gnomAD 0.009%). This variant has not been reported in the literature in individuals affected with MAN2B1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). 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. -

May 29, 2024
Laboratory of Prof. Karen Avraham, Tel Aviv University
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:research

Homozygosity of a rare variant that is predicted to cause damage by most prediction programs -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.23
BayesDel_addAF
Pathogenic
0.27
D
BayesDel_noAF
Pathogenic
0.33
CADD
Pathogenic
32
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.85
D;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.96
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.96
D;D
M_CAP
Benign
0.078
D
MetaRNN
Pathogenic
0.97
D;D
MetaSVM
Pathogenic
0.92
D
MutationAssessor
Pathogenic
3.9
H;.
PhyloP100
7.9
PrimateAI
Uncertain
0.60
T
PROVEAN
Pathogenic
-6.7
D;D
REVEL
Pathogenic
0.80
Sift
Pathogenic
0.0
D;D
Sift4G
Pathogenic
0.0
D;D
Polyphen
1.0
D;.
Vest4
0.86
MutPred
0.88
Gain of sheet (P = 0.1539);.;
MVP
0.99
MPC
1.0
ClinPred
1.0
D
GERP RS
5.9
Varity_R
0.65
gMVP
0.89
Mutation Taster
=34/66
disease causing

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: rs758755293; hg19: chr19-12757478; COSMIC: COSV99666948; COSMIC: COSV99666948; API