9-137087025-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2BP4_StrongBS1_Supporting

The NM_016219.5(MAN1B1):c.26G>C(p.Ser9Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000592 in 1,601,582 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00030 ( 0 hom., cov: 34)

Exomes 𝑓: 0.00062 ( 1 hom. )

Consequence

MAN1B1
NM_016219.5 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.509

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.027214408).

BS1

Variant frequency is greater than expected in population nfe. gnomad4 allele frequency = 0.000302 (46/152274) while in subpopulation NFE AF= 0.000661 (45/68046). AF 95% confidence interval is 0.000507. There are 0 homozygotes in gnomad4. There are 19 alleles in male gnomad4 subpopulation. Median coverage is 34. This position pass quality control queck. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE
MAN1B1	NM_016219.5 linkuse as main transcript	c.26G>C	p.Ser9Thr	missense_variant	1/13	ENST00000371589.9
MAN1B1	XM_006716945.5 linkuse as main transcript	c.26G>C	p.Ser9Thr	missense_variant	1/12
MAN1B1	NR_045720.2 linkuse as main transcript	n.41G>C		non_coding_transcript_exon_variant	1/13
MAN1B1	NR_045721.2 linkuse as main transcript	n.41G>C		non_coding_transcript_exon_variant	1/14

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
MAN1B1	ENST00000371589.9 linkuse as main transcript	c.26G>C	p.Ser9Thr	missense_variant	1/13	1	NM_016219.5	P2

Frequencies

GnomAD3 genomes

AF:

0.000302

AC:

AN:

152274

Hom.:

Cov.:

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:

0.000661

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000202

AC:

AN:

222516

Hom.:

AF XY:

0.000223

AC XY:

AN XY:

120958

show subpopulations

Gnomad AFR exome

AF:

0.000146

Gnomad AMR exome

AF:

0.0000312

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000407

Gnomad OTH exome

AF:

0.000372

GnomAD4 exome

AF:

0.000622

AC:

902

AN:

1449308

Hom.:

Cov.:

AF XY:

0.000596

AC XY:

429

AN XY:

719822

show subpopulations

Gnomad4 AFR exome

AF:

0.000180

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.000736

Gnomad4 OTH exome

AF:

0.00135

GnomAD4 genome

AF:

0.000302

AC:

AN:

152274

Hom.:

Cov.:

AF XY:

0.000255

AC XY:

AN XY:

74408

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:

0.000661

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000380

Hom.:

Bravo

AF:

0.000363

TwinsUK

AF:

0.00108

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000700

AC:

ExAC

AF:

0.000117

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Rafiq syndrome

Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	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. -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Sep 07, 2022	This sequence change replaces serine, which is neutral and polar, with threonine, which is neutral and polar, at codon 9 of the MAN1B1 protein (p.Ser9Thr). This variant is present in population databases (rs140568381, gnomAD 0.04%). 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: 588165). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The threonine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. 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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 25, 2018

The p.S9T variant (also known as c.26G>C), located in coding exon 1 of the MAN1B1 gene, results from a G to C substitution at nucleotide position 26. The serine at codon 9 is replaced by threonine, an amino acid with similar properties. This amino acid position is not well conserved in available vertebrate species. 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

0.084

BayesDel_addAF

Benign

-0.49

BayesDel_noAF

Benign

-0.60

Cadd

Benign

6.2

Dann

Benign

0.75

DEOGEN2

Benign

0.0070

Eigen

Benign

-1.2

Eigen_PC

Benign

-1.2

FATHMM_MKL

Benign

0.11

LIST_S2

Benign

0.35

M_CAP

Benign

0.019

MetaRNN

Benign

0.027

MetaSVM

Benign

-0.96

MutationAssessor

Benign

0.69

MutationTaster

Benign

1.0

PrimateAI

Uncertain

0.56

PROVEAN

Benign

-0.090

REVEL

Benign

0.040

Sift

Benign

0.63

Sift4G

Benign

0.80

Polyphen

0.0

Vest4

0.18

MVP

0.14

MPC

0.070

ClinPred

0.010

GERP RS

1.5

Varity_R

0.075

gMVP

0.14

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over