Genetic Variant MAN1B1:p.Arg265Leu (chr9-137099759-G-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_016219.5(MAN1B1):c.794G>T(p.Arg265Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,834 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R265H) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MAN1B1
NM_016219.5 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 2.56

Publications

5 publications found

Variant links:

Genes affected

MAN1B1 (HGNC:6823): (mannosidase alpha class 1B member 1) This gene encodes an enzyme belonging to the glycosyl hydrolase 47 family. This enzyme functions in N-glycan biosynthesis, and is a class I alpha-1,2-mannosidase that specifically converts Man9GlcNAc to Man8GlcNAc isomer B. It is required for N-glycan trimming to Man5-6GlcNAc2 in the endoplasmic-reticulum-associated degradation pathway. Mutations in this gene cause autosomal-recessive intellectual disability. Alternative splicing results in multiple transcript variants. A related pseudogene has been identified on chromosome 11. [provided by RefSeq, Dec 2011]

MAN1B1 Gene-Disease associations (from GenCC):

MAN1B1-congenital disorder of glycosylation
Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
Rafiq syndrome
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
autosomal recessive non-syndromic intellectual disability
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

MAN1B1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein
MAN1B1	NM_016219.5 link	c.794G>T	p.Arg265Leu	missense_variant	Exon 6 of 13	ENST00000371589.9	NP_057303.2
MAN1B1	XM_006716945.5 link	c.794G>T	p.Arg265Leu	missense_variant	Exon 6 of 12		XP_006717008.1
MAN1B1	NR_045720.2 link	n.809G>T		non_coding_transcript_exon_variant	Exon 6 of 13
MAN1B1	NR_045721.2 link	n.940G>T		non_coding_transcript_exon_variant	Exon 7 of 14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAN1B1	ENST00000371589.9 link	c.794G>T	p.Arg265Leu	missense_variant	Exon 6 of 13	1	NM_016219.5	ENSP00000360645.4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251482

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461834

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727222

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53372

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1112002

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.23

BayesDel_addAF

Benign

-0.034

BayesDel_noAF

Benign

-0.20

CADD

Benign

(source)

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.47

T;T

Eigen

Benign

-0.074

Eigen_PC

Benign

-0.13

FATHMM_MKL

Uncertain

0.86

LIST_S2

Pathogenic

0.99

D;D

M_CAP

Uncertain

0.19

MetaRNN

Uncertain

0.63

D;D

MetaSVM

Benign

-0.66

MutationAssessor

Benign

2.0

M;.

PhyloP100

2.6

PrimateAI

Benign

0.30

PROVEAN

Uncertain

-4.3

D;.

REVEL

Uncertain

0.36

Sift

Uncertain

0.0070

D;.

Sift4G

Uncertain

0.018

D;D

Vest4

0.35

ClinPred

0.83

GERP RS

2.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.43

gMVP

0.69

Mutation Taster

=86/14

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over