chr19-12657475-G-A

Variant names:

• chr19-12657475-G-A
• rs1555708126
• NM_000528.4:c.1390C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000528.4(MAN2B1):​c.1390C>T​(p.Gln464*) variant causes a stop gained change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (no stars). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: MAN2B1 NM_000528.4 stop_gained
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 3.85
• Publications: 0 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)

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-12657475-G-A is Pathogenic according to our data. Variant chr19-12657475-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 551124.Status of the report is no_assertion_criteria_provided, 0 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
MAN2B1	NM_000528.4	c.1390C>T	p.Gln464*	stop_gained	Exon 11 of 24	ENST00000456935.7	NP_000519.2
MAN2B1	NM_001440570.1	c.1393C>T	p.Gln465*	stop_gained	Exon 11 of 24		NP_001427499.1
MAN2B1	NM_001173498.2	c.1387C>T	p.Gln463*	stop_gained	Exon 11 of 24		NP_001166969.1
MAN2B1	XM_047438841.1	c.289C>T	p.Gln97*	stop_gained	Exon 4 of 17		XP_047294797.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
MAN2B1	ENST00000456935.7	c.1390C>T	p.Gln464*	stop_gained	Exon 11 of 24	1	NM_000528.4	ENSP00000395473.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1410070 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 697114

African (AFR) AF: 0.00 AC: 0 AN: 32328

American (AMR) AF: 0.00 AC: 0 AN: 37282

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25232

East Asian (EAS) AF: 0.00 AC: 0 AN: 36930

South Asian (SAS) AF: 0.00 AC: 0 AN: 80158

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48772

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4798

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1086236

Other (OTH) AF: 0.00 AC: 0 AN: 58334

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Deficiency of alpha-mannosidase Pathogenic:1

Mar 16, 2017

Counsyl

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	37
DANN	Uncertain	1.0
Eigen	Uncertain	0.53
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.88	D
PhyloP100		3.8
Vest4		0.24
GERP RS		3.6
Mutation Taster		=0/200	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1555708126; hg19: chr19-12768289;