NM_016219.5:c.1987G>A

Variant names:

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

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

MAN1B1 links:

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
MAN1B1	NM_016219.5 link	c.1987G>A	p.Glu663Lys	missense_variant	Exon 13 of 13	ENST00000371589.9	NP_057303.2	Q9UKM7
MAN1B1	NR_045720.2 link	n.1977G>A		non_coding_transcript_exon_variant	Exon 13 of 13
MAN1B1	NR_045721.2 link	n.2133G>A		non_coding_transcript_exon_variant	Exon 14 of 14
MAN1B1	XM_006716945.5 link	c.*516G>A		downstream_gene_variant			XP_006717008.1	H0YG20

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAN1B1	ENST00000371589.9 link	c.1987G>A	p.Glu663Lys	missense_variant	Exon 13 of 13	1	NM_016219.5	ENSP00000360645.4		Q9UKM7

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000137

AC:

AN:

1461622

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727120

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

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:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53240

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000180

AC:

AN:

1111930

Other (OTH)

AF:

0.00

AC:

AN:

60390

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.525

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

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.00000824

AC:

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

BayesDel_noAF

Pathogenic

0.42

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.81

Eigen

Pathogenic

0.77

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Uncertain

0.96

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.40

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.9

PhyloP100

7.5

PrimateAI

Uncertain

0.67

PROVEAN

Uncertain

-3.5

REVEL

Pathogenic

0.95

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

Polyphen

1.0

Vest4

0.94

MVP

0.95

MPC

0.46

ClinPred

1.0

GERP RS

5.4

Varity_R

0.96

gMVP

0.96

Mutation Taster

=27/73

disease causing

(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

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over