chr19-12647481-C-G

Variant summary

Our verdict is Benign. Variant got -7 ACMG points: 2P and 9B. PM2BP4_StrongBP6BS1

The NM_000528.4(MAN2B1):ā€‹c.2782G>Cā€‹(p.Gly928Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000731 in 1,614,110 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 Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in same amino acid change has been previously reported as Likely benignin ClinVar. Synonymous variant affecting the same amino acid position (i.e. G928G) has been classified as Likely benign.

Frequency

Genomes: š‘“ 0.000053 ( 0 hom., cov: 32)
Exomes š‘“: 0.000075 ( 1 hom. )

Consequence

MAN2B1
NM_000528.4 missense

Scores

2
17

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:6

Conservation

PhyloP100: 0.709
Variant links:
Genes affected
MAN2B1 (HGNC:6826): (mannosidase alpha class 2B member 1) This gene encodes an enzyme that hydrolyzes terminal, non-reducing alpha-D-mannose residues in alpha-D-mannosides. Its activity is necessary for the catabolism of N-linked carbohydrates released during glycoprotein turnover and it is member of family 38 of glycosyl hydrolases. The full length protein is processed in two steps. First, a 49 aa leader sequence is cleaved off and the remainder of the protein is processed into 3 peptides of 70 kDa, 42 kDa (D) and 13/15 kDa (E). Next, the 70 kDa peptide is further processed into three peptides (A, B and C). The A, B and C peptides are disulfide-linked. Defects in this gene have been associated with lysosomal alpha-mannosidosis. Alternatively spliced transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Mar 2010]

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ACMG classification

Classification made for transcript

Verdict is Benign. Variant got -7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.016765296).
BP6
Variant 19-12647481-C-G is Benign according to our data. Variant chr19-12647481-C-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 287586.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=4, Uncertain_significance=1}.
BS1
Variant frequency is greater than expected in population amr. gnomad4_exome allele frequency = 0.0000752 (110/1461890) while in subpopulation AMR AF= 0.00246 (110/44724). AF 95% confidence interval is 0.00209. There are 1 homozygotes in gnomad4_exome. There are 42 alleles in male gnomad4_exome subpopulation. Median coverage is 33. This position pass quality control queck.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
MAN2B1NM_000528.4 linkuse as main transcriptc.2782G>C p.Gly928Arg missense_variant 22/24 ENST00000456935.7
MAN2B1NM_001173498.2 linkuse as main transcriptc.2779G>C p.Gly927Arg missense_variant 22/24
MAN2B1XM_005259913.3 linkuse as main transcriptc.2785G>C p.Gly929Arg missense_variant 22/24
MAN2B1XM_047438841.1 linkuse as main transcriptc.1681G>C p.Gly561Arg missense_variant 15/17

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
MAN2B1ENST00000456935.7 linkuse as main transcriptc.2782G>C p.Gly928Arg missense_variant 22/241 NM_000528.4 A1O00754-1

Frequencies

GnomAD3 genomes
AF:
0.0000526
AC:
8
AN:
152220
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000523
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:
0.000362
AC:
91
AN:
251214
Hom.:
1
AF XY:
0.000258
AC XY:
35
AN XY:
135780
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00263
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:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000752
AC:
110
AN:
1461890
Hom.:
1
Cov.:
33
AF XY:
0.0000578
AC XY:
42
AN XY:
727248
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00246
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:
0.00
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000526
AC:
8
AN:
152220
Hom.:
0
Cov.:
32
AF XY:
0.0000672
AC XY:
5
AN XY:
74356
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.000523
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:
0.000136
ExAC
AF:
0.000296
AC:
36

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:6
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Deficiency of alpha-mannosidase Uncertain:2Benign:3
Likely benign, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 25, 2024- -
Uncertain significance, no assertion criteria providedclinical testingBaylor GeneticsOct 03, 2014Our laboratory reported dual molecular diagnoses in SCN8A (NM_014191.3, c.647T>G) and MAN2B1 (NM_000528.3, c.2782G>C and c.1383C>G in trans) in one individual with reported features that include delayed motor milestones, delayed speech, intellectual disability, hypotonia, seizure disorder (refractory epilepsy), abnormal movements (dyskinesia), minor dysmorphic features (flat nasal bridge, prominent eyes, full lips), microcephaly, dysphagia, and cortical visual impairment. Heterozygotes for the MAN2B1 variants would be expected to be asymptomatic carriers. -
Uncertain significance, criteria provided, single submitterclinical testingCounsylSep 28, 2017- -
Likely benign, criteria provided, single submitterclinical testingGenome-Nilou LabSep 05, 2021- -
Benign, no assertion criteria providedclinical testingNatera, Inc.Jan 28, 2020- -
not specified Benign:2
Likely benign, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpJun 22, 2022Variant summary: MAN2B1 c.2782G>C (p.Gly928Arg) results in a non-conservative amino acid change located in the glycosyl hydrolases family 38, C-terminal beta sandwich domain (IPR041147) of the encoded protein sequence. Three of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 0.00036 in 251214 control chromosomes (gnomAD), predominantly at a frequency of 0.0026 within the Latino subpopulation in the gnomAD database, including 1 homozygote. The observed variant frequency within Latino control individuals in the gnomAD database is approximately 1.64 fold of the estimated maximal expected allele frequency for a pathogenic variant in MAN2B1 causing Alpha-Mannosidosis (0.0016), suggesting that the variant is a benign polymorphism found primarily in populations of Latino origin. To our knowledge, no occurrence of c.2782G>C in individuals affected with Alpha-Mannosidosis and no experimental evidence demonstrating its impact on protein function have been reported. Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. Three laboratories classified the variant as likely benign, one as benign, and one as VUS. Based on the evidence outlined above, the variant was classified as likely benign. -
Likely benign, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Apr 18, 2016- -
MAN2B1-related disorder Benign:1
Likely benign, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesSep 25, 2024This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.085
BayesDel_addAF
Benign
-0.42
T
BayesDel_noAF
Benign
-0.38
CADD
Benign
15
DANN
Benign
0.77
DEOGEN2
Benign
0.30
T;.
Eigen
Benign
-0.90
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.23
N
LIST_S2
Benign
0.48
T;T
M_CAP
Benign
0.022
T
MetaRNN
Benign
0.017
T;T
MetaSVM
Benign
-0.66
T
MutationAssessor
Uncertain
2.4
M;.
MutationTaster
Benign
1.0
N;N
PrimateAI
Benign
0.32
T
PROVEAN
Benign
-1.3
N;N
REVEL
Uncertain
0.32
Sift
Benign
0.54
T;T
Sift4G
Benign
0.17
T;T
Polyphen
0.94
P;.
Vest4
0.31
MutPred
0.39
Gain of solvent accessibility (P = 0.019);.;
MVP
0.78
MPC
0.67
ClinPred
0.12
T
GERP RS
-5.6
Varity_R
0.027
gMVP
0.53

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.020
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.

Other links and lift over

dbSNP: rs754733253; hg19: chr19-12758295; API