rs967834240

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PVS1_SupportingPM2

The NM_000528.4(MAN2B1):​c.1A>T​(p.Met1?) variant causes a initiator codon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,396,534 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: not found (cov: 33)
Exomes 𝑓: 0.000019 ( 0 hom. )

Consequence

MAN2B1
NM_000528.4 initiator_codon

Scores

6
3
7

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.93
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]
WDR83 (HGNC:32672): (WD repeat domain 83) This gene encodes a member of the WD-40 protein family. The protein is proposed to function as a molecular scaffold for various multimeric protein complexes. The protein associates with several components of the extracellular signal-regulated kinase (ERK) pathway, and promotes ERK activity in response to serum or other signals. The protein also interacts with egl nine homolog 3 (EGLN3, also known as PHD3) and regulates expression of hypoxia-inducible factor 1, and has been purified as part of the spliceosome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2009]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PVS1
Start lost variant, no pathogenic variants between lost start and next in-frame start position. Next in-frame start position is after 24 codons. Genomic position: 12666632. Lost 0.023 part of the original CDS.
PM2
Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN2B1NM_000528.4 linkc.1A>T p.Met1? initiator_codon_variant Exon 1 of 24 ENST00000456935.7 NP_000519.2 O00754-1
WDR83NM_001099737.3 linkc.-448T>A upstream_gene_variant ENST00000418543.8 NP_001093207.1 Q9BRX9

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN2B1ENST00000456935.7 linkc.1A>T p.Met1? initiator_codon_variant Exon 1 of 24 1 NM_000528.4 ENSP00000395473.2 O00754-1
ENSG00000269590ENST00000597961.1 linkc.151-896A>T intron_variant Intron 2 of 4 4 ENSP00000472710.1 M0R2P5
WDR83ENST00000418543.8 linkc.-448T>A upstream_gene_variant 1 NM_001099737.3 ENSP00000402653.3 Q9BRX9

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD3 exomes
AF:
0.00000684
AC:
1
AN:
146180
Hom.:
0
AF XY:
0.0000127
AC XY:
1
AN XY:
78864
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:
0.0000184
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000186
AC:
26
AN:
1396534
Hom.:
0
Cov.:
31
AF XY:
0.0000160
AC XY:
11
AN XY:
688816
show subpopulations
Gnomad4 AFR exome
AF:
0.00
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:
0.0000232
Gnomad4 OTH exome
AF:
0.0000173
GnomAD4 genome
Cov.:
33

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Uncertain:2
Jun 08, 2017
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 29, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change affects the initiator methionine of the MAN2B1 mRNA. The next in-frame methionine is located at codon 24. 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 variant has not been reported in the literature in individuals affected with MAN2B1-related conditions. ClinVar contains an entry for this variant (Variation ID: 552407). 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
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.38
CADD
Benign
19
DANN
Benign
0.86
DEOGEN2
Benign
0.12
T;.;.;.
Eigen
Benign
-0.27
Eigen_PC
Benign
-0.22
FATHMM_MKL
Uncertain
0.87
D
LIST_S2
Uncertain
0.90
D;D;D;D
M_CAP
Pathogenic
0.55
D
MetaRNN
Pathogenic
0.98
D;D;D;D
MetaSVM
Benign
-0.48
T
PROVEAN
Benign
-0.81
N;N;.;.
REVEL
Uncertain
0.45
Sift
Pathogenic
0.0
D;D;.;.
Sift4G
Pathogenic
0.0
D;D;.;D
Polyphen
0.075
B;.;.;.
Vest4
0.91
MutPred
0.99
Loss of catalytic residue at M1 (P = 0.0243);Loss of catalytic residue at M1 (P = 0.0243);Loss of catalytic residue at M1 (P = 0.0243);Loss of catalytic residue at M1 (P = 0.0243);
MVP
0.90
ClinPred
0.79
D
GERP RS
3.3
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.97
gMVP
0.75

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

LitVar

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

Other links and lift over

dbSNP: rs967834240; hg19: chr19-12777515; API