rs201448121

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000528.4(MAN2B1):c.718C>T(p.Arg240Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000197 in 1,613,972 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R240Q) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00015 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00020 ( 0 hom. )

Consequence

MAN2B1
NM_000528.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 2.14

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
MAN2B1	NM_000528.4 linkuse as main transcript	c.718C>T	p.Arg240Trp	missense_variant	5/24	ENST00000456935.7
MAN2B1	NM_001173498.2 linkuse as main transcript	c.718C>T	p.Arg240Trp	missense_variant	5/24
MAN2B1	XM_005259913.3 linkuse as main transcript	c.718C>T	p.Arg240Trp	missense_variant	5/24

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MAN2B1	ENST00000456935.7 linkuse as main transcript	c.718C>T	p.Arg240Trp	missense_variant	5/24	1	NM_000528.4	A1	O00754-1
MAN2B1	ENST00000221363.8 linkuse as main transcript	c.718C>T	p.Arg240Trp	missense_variant	5/24	1		P4	O00754-2
MAN2B1	ENST00000486847.2 linkuse as main transcript	c.421C>T	p.Arg141Trp	missense_variant	3/4	4
MAN2B1	ENST00000466794.5 linkuse as main transcript	n.700C>T		non_coding_transcript_exon_variant	5/22	2

Frequencies

GnomAD3 genomes

AF:

0.000151

AC:

AN:

152126

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000577

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000471

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000176

Gnomad OTH

AF:

0.000478

GnomAD3 exomes

AF:

0.000283

AC:

AN:

250948

Hom.:

AF XY:

0.000236

AC XY:

AN XY:

135740

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000417

Gnomad NFE exome

AF:

0.000511

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000202

AC:

295

AN:

1461728

Hom.:

Cov.:

AF XY:

0.000179

AC XY:

130

AN XY:

727154

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000504

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.000468

Gnomad4 NFE exome

AF:

0.000228

Gnomad4 OTH exome

AF:

0.000199

GnomAD4 genome

AF:

0.000151

AC:

AN:

152244

Hom.:

Cov.:

AF XY:

0.000175

AC XY:

AN XY:

74448

show subpopulations

Gnomad4 AFR

AF:

0.0000482

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000579

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000471

Gnomad4 NFE

AF:

0.000176

Gnomad4 OTH

AF:

0.000473

Alfa

AF:

0.000177

Hom.:

Bravo

AF:

0.000121

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000349

AC:

ExAC

AF:

0.000420

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase

Uncertain:2

Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 13, 2022	This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 240 of the MAN2B1 protein (p.Arg240Trp). This variant is present in population databases (rs201448121, gnomAD 0.05%). 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: 565747). 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

not provided

Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Mayo Clinic Laboratories, Mayo Clinic

Nov 17, 2021

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Uncertain

0.14

BayesDel_noAF

Pathogenic

0.30

Cadd

Uncertain

Dann

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

D;.;.

Eigen

Uncertain

0.28

Eigen_PC

Benign

0.096

FATHMM_MKL

Uncertain

0.91

LIST_S2

Pathogenic

0.99

D;D;D

M_CAP

Uncertain

0.28

MetaRNN

Uncertain

0.71

D;D;D

MetaSVM

Uncertain

0.66

MutationAssessor

Pathogenic

3.4

M;M;.

MutationTaster

Benign

1.0

D;D

PrimateAI

Benign

0.43

PROVEAN

Pathogenic

-6.3

D;D;.

REVEL

Pathogenic

0.69

Sift

Uncertain

0.0020

D;D;.

Sift4G

Pathogenic

0.0010

D;D;.

Polyphen

1.0

D;.;.

Vest4

0.84

MVP

0.91

MPC

1.5

ClinPred

0.61

GERP RS

0.79

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.54

gMVP

0.90

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.21

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.21

Position offset: 7

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over