rs777270726

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_016219.5(MAN1B1):​c.1897G>A​(p.Val633Ile) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000062 in 1,613,368 control chromosomes in the GnomAD database, with no homozygous occurrence. 2/3 splice prediction tools predicting alterations to normal splicing. 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. V633F) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

MAN1B1
NM_016219.5 missense, splice_region

Scores

1
10
7
Splicing: ADA: 0.9998
2

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 6.26

Publications

1 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. No scorers claiming Uncertain. Scorers claiming Benign: max_spliceai.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016219.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MAN1B1
NM_016219.5
MANE Select
c.1897G>Ap.Val633Ile
missense splice_region
Exon 13 of 13NP_057303.2
MAN1B1
NR_045720.2
n.1887G>A
splice_region non_coding_transcript_exon
Exon 13 of 13
MAN1B1
NR_045721.2
n.2043G>A
splice_region non_coding_transcript_exon
Exon 14 of 14

Ensembl Transcripts

Selected
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
MAN1B1
ENST00000371589.9
TSL:1 MANE Select
c.1897G>Ap.Val633Ile
missense splice_region
Exon 13 of 13ENSP00000360645.4
MAN1B1
ENST00000371587.9
TSL:1
n.*1574G>A
splice_region non_coding_transcript_exon
Exon 14 of 14ENSP00000483132.2
MAN1B1
ENST00000371587.9
TSL:1
n.*1574G>A
3_prime_UTR
Exon 14 of 14ENSP00000483132.2

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152176
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000479
AC:
7
AN:
1461192
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726898
show subpopulations
African (AFR)
AF:
0.000149
AC:
5
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44720
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52904
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5752
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111882
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60370
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.496
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.0000197
AC:
3
AN:
152176
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74334
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.0000724
AC:
3
AN:
41436
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00380082), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.342
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.074
BayesDel_addAF
Uncertain
0.054
T
BayesDel_noAF
Benign
-0.16
CADD
Benign
22
DANN
Uncertain
1.0
DEOGEN2
Benign
0.22
T
Eigen
Uncertain
0.50
Eigen_PC
Uncertain
0.51
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Benign
0.77
T
M_CAP
Uncertain
0.17
D
MetaRNN
Uncertain
0.45
T
MetaSVM
Uncertain
-0.049
T
MutationAssessor
Uncertain
2.2
M
PhyloP100
6.3
PrimateAI
Uncertain
0.50
T
PROVEAN
Benign
-0.78
N
REVEL
Uncertain
0.36
Sift
Benign
0.12
T
Sift4G
Benign
0.095
T
Polyphen
0.37
B
Vest4
0.26
MutPred
0.61
Loss of MoRF binding (P = 0.1214)
MVP
0.68
MPC
0.27
ClinPred
0.80
D
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.25
gMVP
0.58
Mutation Taster
=25/75
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.97
SpliceAI score (max)
0.16
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: rs777270726; hg19: chr9-140002840; API