9-137108388-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_016219.5(MAN1B1):​c.1897G>T​(p.Val633Phe) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.0000167 in 1,613,366 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000018 ( 0 hom. )

Consequence

MAN1B1
NM_016219.5 missense, splice_region

Scores

13
4
2
Splicing: ADA: 0.9999
2

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.26
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

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

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
MAN1B1NM_016219.5 linkc.1897G>T p.Val633Phe missense_variant, splice_region_variant Exon 13 of 13 ENST00000371589.9 NP_057303.2 Q9UKM7
MAN1B1NR_045720.2 linkn.1887G>T splice_region_variant, non_coding_transcript_exon_variant Exon 13 of 13
MAN1B1NR_045721.2 linkn.2043G>T splice_region_variant, non_coding_transcript_exon_variant Exon 14 of 14
MAN1B1XM_006716945.5 linkc.*426G>T downstream_gene_variant XP_006717008.1 H0YG20

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
MAN1B1ENST00000371589.9 linkc.1897G>T p.Val633Phe missense_variant, splice_region_variant Exon 13 of 13 1 NM_016219.5 ENSP00000360645.4 Q9UKM7

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
33
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000800
AC:
2
AN:
250126
Hom.:
0
AF XY:
0.0000148
AC XY:
2
AN XY:
135348
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.0000327
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000889
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461190
Hom.:
0
Cov.:
32
AF XY:
0.0000206
AC XY:
15
AN XY:
726898
show subpopulations
Gnomad4 AFR exome
AF:
0.0000299
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000207
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152176
Hom.:
0
Cov.:
33
AF XY:
0.0000135
AC XY:
1
AN XY:
74334
show subpopulations
Gnomad4 AFR
AF:
0.0000241
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.00
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000151
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.0000593

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Rafiq syndrome Uncertain:2
Aug 22, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 633 of the MAN1B1 protein (p.Val633Phe). This variant is present in population databases (rs777270726, gnomAD 0.003%). This missense change has been observed in individual(s) with clinical features of MAN1B1-related conditions (Invitae). ClinVar contains an entry for this variant (Variation ID: 539744). 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: "Probably Damaging"; Align-GVGD: "Class C0"). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus 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. -

-
Baylor Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.30
BayesDel_addAF
Pathogenic
0.33
D
BayesDel_noAF
Pathogenic
0.34
CADD
Uncertain
25
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.70
D
Eigen
Pathogenic
0.97
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.89
D
M_CAP
Pathogenic
0.54
D
MetaRNN
Pathogenic
0.97
D
MetaSVM
Pathogenic
0.81
D
MutationAssessor
Pathogenic
3.9
H
PrimateAI
Uncertain
0.60
T
PROVEAN
Pathogenic
-4.4
D
REVEL
Pathogenic
0.88
Sift
Pathogenic
0.0
D
Sift4G
Pathogenic
0.0010
D
Polyphen
1.0
D
Vest4
0.83
MutPred
0.72
Loss of MoRF binding (P = 0.085);
MVP
0.95
MPC
0.50
ClinPred
0.99
D
GERP RS
5.4
Varity_R
0.94
gMVP
0.90

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.99
SpliceAI score (max)
0.49
Details are displayed if max score is > 0.2
DS_AL_spliceai
0.49
Position offset: 0

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.

Other links and lift over

dbSNP: rs777270726; hg19: chr9-140002840; COSMIC: COSV65371728; COSMIC: COSV65371728; API