9-137087006-G-T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_016219.5(MAN1B1):​c.7G>T​(p.Ala3Ser) variant causes a missense change. The variant allele was found at a frequency of 0.0000295 in 1,594,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. A3A) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000029 ( 0 hom. )

Consequence

MAN1B1
NM_016219.5 missense

Scores

3
16

Clinical Significance

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

Conservation

PhyloP100: 5.18

Publications

0 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-DT (HGNC:48715): (MAN1B1 divergent transcript)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.048623055).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN1B1NM_016219.5 linkc.7G>T p.Ala3Ser missense_variant Exon 1 of 13 ENST00000371589.9 NP_057303.2 Q9UKM7

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN1B1ENST00000371589.9 linkc.7G>T p.Ala3Ser missense_variant Exon 1 of 13 1 NM_016219.5 ENSP00000360645.4 Q9UKM7

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152272
Hom.:
0
Cov.:
34
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000945
AC:
2
AN:
211728
AF XY:
0.0000174
show subpopulations
Gnomad AFR exome
AF:
0.0000767
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000108
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000291
AC:
42
AN:
1442430
Hom.:
0
Cov.:
31
AF XY:
0.0000349
AC XY:
25
AN XY:
715548
show subpopulations
African (AFR)
AF:
0.000120
AC:
4
AN:
33376
American (AMR)
AF:
0.00
AC:
0
AN:
41442
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25516
East Asian (EAS)
AF:
0.0000513
AC:
2
AN:
38986
South Asian (SAS)
AF:
0.00
AC:
0
AN:
82970
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
50194
Middle Eastern (MID)
AF:
0.000179
AC:
1
AN:
5576
European-Non Finnish (NFE)
AF:
0.0000281
AC:
31
AN:
1104656
Other (OTH)
AF:
0.0000670
AC:
4
AN:
59714
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.444
Heterozygous variant carriers
0
3
6
9
12
15
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:
0.0000328
AC:
5
AN:
152390
Hom.:
0
Cov.:
34
AF XY:
0.0000403
AC XY:
3
AN XY:
74528
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41598
American (AMR)
AF:
0.00
AC:
0
AN:
15312
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5180
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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

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:
0.000123
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000334
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Rafiq syndrome Uncertain:2
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Oct 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with serine, which is neutral and polar, at codon 3 of the MAN1B1 protein (p.Ala3Ser). 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 MAN1B1-related conditions. ClinVar contains an entry for this variant (Variation ID: 589168). 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: "Possibly 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. -

Inborn genetic diseases Uncertain:1
May 31, 2017
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A3S variant (also known as c.7G>T), located in coding exon 1 of the MAN1B1 gene, results from a G to T substitution at nucleotide position 7. The alanine at codon 3 is replaced by serine, an amino acid with similar properties. This amino acid position is not well conserved on limited sequence alignment. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.099
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.53
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Benign
0.0073
T
Eigen
Benign
-0.48
Eigen_PC
Benign
-0.50
FATHMM_MKL
Benign
0.40
N
LIST_S2
Benign
0.48
T
M_CAP
Uncertain
0.14
D
MetaRNN
Benign
0.049
T
MetaSVM
Benign
-1.1
T
MutationAssessor
Benign
0.69
N
PhyloP100
5.2
PrimateAI
Uncertain
0.54
T
PROVEAN
Benign
0.020
N
REVEL
Benign
0.022
Sift
Benign
0.30
T
Sift4G
Benign
0.36
T
Polyphen
0.61
P
Vest4
0.28
MutPred
0.23
Gain of relative solvent accessibility (P = 0.0215);
MVP
0.17
MPC
0.30
ClinPred
0.28
T
GERP RS
3.3
PromoterAI
0.0051
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.0
Varity_R
0.11
gMVP
0.090
Mutation Taster
=94/6
polymorphism

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: rs573766677; hg19: chr9-139981458; API