NM_000528.4:c.2675T>C

Variant names:

• chr19-12647588-A-G
• rs864621989
• NM_000528.4:c.2675T>C
• MAN2B1 p.Leu892Pro

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PP3_Strong

The NM_000528.4(MAN2B1):​c.2675T>C​(p.Leu892Pro) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000548 in 1,460,802 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L892M) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: MAN2B1 NM_000528.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2
• Conservation: PhyloP100: 8.58
• 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: Myriad Women's Health, G2P, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), ClinGen, Genomics England PanelApp

ENSG00000269242 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN2B1	NM_000528.4	MANE Select	c.2675T>C	p.Leu892Pro	missense	Exon 22 of 24	NP_000519.2	O00754-1
	MAN2B1	NM_001440570.1		c.2678T>C	p.Leu893Pro	missense	Exon 22 of 24	NP_001427499.1
	MAN2B1	NM_001173498.2		c.2672T>C	p.Leu891Pro	missense	Exon 22 of 24	NP_001166969.1	O00754-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN2B1	ENST00000456935.7	TSL:1 MANE Select	c.2675T>C	p.Leu892Pro	missense	Exon 22 of 24	ENSP00000395473.2	O00754-1
	MAN2B1	ENST00000221363.9	TSL:1	c.2672T>C	p.Leu891Pro	missense	Exon 22 of 24	ENSP00000221363.4	O00754-2
	ENSG00000269242	ENST00000597692.1	TSL:2	n.233T>C		non_coding_transcript_exon	Exon 2 of 5	ENSP00000470240.1	M0QZ24

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000548 AC: 8 AN: 1460802 Hom.: 0 Cov.: 34 AF XY: 0.00000826 AC XY: 6 AN XY: 726638

African (AFR) AF: 0.00 AC: 0 AN: 33458

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

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26074

East Asian (EAS) AF: 0.00 AC: 0 AN: 39644

South Asian (SAS) AF: 0.00 AC: 0 AN: 86222

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53238

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5734

European-Non Finnish (NFE) AF: 0.00000720 AC: 8 AN: 1111394

Other (OTH) AF: 0.00 AC: 0 AN: 60346

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Deficiency of alpha-mannosidase (1)
-	1	-	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.85
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Uncertain	24
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.83	D
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.34
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.77	T
M_CAP	Pathogenic	0.38	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Uncertain	0.38	D
MutationAssessor	Pathogenic	3.5	H
PhyloP100		8.6
PrimateAI	Uncertain	0.69	T
PROVEAN	Pathogenic	-5.8	D
REVEL	Pathogenic	0.74
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Varity_R		0.83
gMVP		0.95
Mutation Taster		=3/97	disease causing

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs864621989;

hg19: chr19-12758402;