chr9-137108478-G-A

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_016219.5(MAN1B1):​c.1987G>A​(p.Glu663Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,622 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

MAN1B1
NM_016219.5 missense

Scores

15
3
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 7.46

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: Likely_pathogenic. The variant received 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.95
PP5
Variant 9-137108478-G-A is Pathogenic according to our data. Variant chr9-137108478-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 539745.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN1B1NM_016219.5 linkc.1987G>A p.Glu663Lys missense_variant Exon 13 of 13 ENST00000371589.9 NP_057303.2 Q9UKM7
MAN1B1NR_045720.2 linkn.1977G>A non_coding_transcript_exon_variant Exon 13 of 13
MAN1B1NR_045721.2 linkn.2133G>A non_coding_transcript_exon_variant Exon 14 of 14
MAN1B1XM_006716945.5 linkc.*516G>A downstream_gene_variant XP_006717008.1 H0YG20

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN1B1ENST00000371589.9 linkc.1987G>A p.Glu663Lys missense_variant Exon 13 of 13 1 NM_016219.5 ENSP00000360645.4 Q9UKM7

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1461622
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727120
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53240
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000180
AC:
2
AN:
1111930
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1
May 10, 2024
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 34258140) -

Rafiq syndrome Uncertain:1
Aug 12, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid with lysine at codon 663 of the MAN1B1 protein (p.Glu663Lys). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and lysine. This variant is present in population databases (rs371136351, ExAC 0.001%). This missense change has been observed in individual(s) with clinical features of MAN1B1-related conditions (Invitae). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. 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
AlphaMissense
Pathogenic
0.97
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.42
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.81
D
Eigen
Pathogenic
0.77
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Uncertain
0.96
D
LIST_S2
Pathogenic
1.0
D
M_CAP
Pathogenic
0.40
D
MetaRNN
Pathogenic
0.95
D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Pathogenic
3.9
H
PhyloP100
7.5
PrimateAI
Uncertain
0.67
T
PROVEAN
Uncertain
-3.5
D
REVEL
Pathogenic
0.95
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0
D
Polyphen
1.0
D
Vest4
0.94
MVP
0.95
MPC
0.46
ClinPred
1.0
D
GERP RS
5.4
Varity_R
0.96
gMVP
0.96
Mutation Taster
=27/73
disease causing

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: rs371136351; hg19: chr9-140002930; API