19-12664832-G-C

Variant names:

• chr19-12664832-G-C
• rs864621977
• NM_000528.4:c.590C>G

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_000528.4(MAN2B1):​c.590C>G​(p.Pro197Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,532 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 Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. P197P) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MAN2B1 NM_000528.4 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:5 U:1
• Conservation: PhyloP100: 9.37
• Publications: 2 publications found

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]

MAN2B1 Gene-Disease associations (from GenCC):

• alpha-mannosidosis

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Genomics England PanelApp, Myriad Women’s Health, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae)

ENSG00000269590 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 16 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000528.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986
• PP5: Variant 19-12664832-G-C is Pathogenic according to our data. Variant chr19-12664832-G-C is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 208254.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000528.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN2B1	NM_000528.4	MANE Select	c.590C>G	p.Pro197Arg	missense	Exon 4 of 24	NP_000519.2
	MAN2B1	NM_001440570.1		c.590C>G	p.Pro197Arg	missense	Exon 4 of 24	NP_001427499.1
	MAN2B1	NM_001173498.2		c.590C>G	p.Pro197Arg	missense	Exon 4 of 24	NP_001166969.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN2B1	ENST00000456935.7	TSL:1 MANE Select	c.590C>G	p.Pro197Arg	missense	Exon 4 of 24	ENSP00000395473.2
	MAN2B1	ENST00000221363.9	TSL:1	c.590C>G	p.Pro197Arg	missense	Exon 4 of 24	ENSP00000221363.4
	ENSG00000269590	ENST00000597961.1	TSL:4	c.581C>G	p.Pro194Arg	missense	Exon 5 of 5	ENSP00000472710.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461532 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727052

African (AFR) AF: 0.00 AC: 0 AN: 33474

American (AMR) AF: 0.00 AC: 0 AN: 44692

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26122

East Asian (EAS) AF: 0.00 AC: 0 AN: 39688

South Asian (SAS) AF: 0.00 AC: 0 AN: 86214

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53272

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111922

Other (OTH) AF: 0.00 AC: 0 AN: 60380

GnomAD4 genome Cov.: 33

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
3	1	-	Deficiency of alpha-mannosidase (4)
1	-	-	Inborn genetic diseases (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.92	D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		9.4
PrimateAI	Uncertain	0.70	T
PROVEAN	Pathogenic	-8.8	D
REVEL	Pathogenic	0.91
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.99
MutPred		0.94		Gain of MoRF binding (P = 0.0756)
MVP		0.98
MPC		1.6
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.95
gMVP		0.97
Mutation Taster		=5/95	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs864621977; hg19: chr19-12775646;