rs778399351

Variant names:

• chr19-12665365-GT-G
• rs778399351
• NM_000528.4:c.422delA

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000528.4(MAN2B1):​c.422delA​(p.Asp141AlafsTer16) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,184 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
• Consequence: MAN2B1 NM_000528.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 0.840
• Publications: 1 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

ENSG00000269590 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 18 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 19-12665365-GT-G is Pathogenic according to our data. Variant chr19-12665365-GT-G is described in ClinVar as Pathogenic. ClinVar VariationId is 371425.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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN2B1	NM_000528.4	MANE Select	c.422delA	p.Asp141AlafsTer16	frameshift	Exon 3 of 24	NP_000519.2	O00754-1
	MAN2B1	NM_001440570.1		c.422delA	p.Asp141AlafsTer16	frameshift	Exon 3 of 24	NP_001427499.1
	MAN2B1	NM_001173498.2		c.422delA	p.Asp141AlafsTer16	frameshift	Exon 3 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.422delA	p.Asp141AlafsTer16	frameshift	Exon 3 of 24	ENSP00000395473.2	O00754-1
	MAN2B1	ENST00000221363.9	TSL:1	c.422delA	p.Asp141AlafsTer16	frameshift	Exon 3 of 24	ENSP00000221363.4	O00754-2
	ENSG00000269590	ENST00000597961.1	TSL:4	c.413delA	p.Asp138AlafsTer16	frameshift	Exon 4 of 5	ENSP00000472710.1	M0R2P5

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152184 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000408 AC: 1 AN: 245084 AF XY: 0.00000753

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152184 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74348

African (AFR) AF: 0.00 AC: 0 AN: 41434

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5198

South Asian (SAS) AF: 0.00 AC: 0 AN: 4834

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68042

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
5	-	-	Deficiency of alpha-mannosidase (5)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.84
Mutation Taster		=2/198	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

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

Other links and lift over

dbSNP: rs778399351;

hg19: chr19-12776179;