rs786204715

Variant names:

• chr19-12658428-C-T
• rs786204715
• NM_000528.4:c.1109G>A

Variant summary

Our verdict is Pathogenic. The variant received 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000528.4(MAN2B1):​c.1109G>A​(p.Trp370*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: MAN2B1 NM_000528.4 stop_gained, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:7
• Conservation: PhyloP100: 7.37
• 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: ClinGen, Genomics England PanelApp, G2P, Laboratory for Molecular Medicine, Myriad Women’s Health, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Pathogenic. The variant received 22 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
• PP3: Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 19-12658428-C-T is Pathogenic according to our data. Variant chr19-12658428-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 189118.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.1109G>A	p.Trp370*	stop_gained splice_region	Exon 8 of 24	NP_000519.2	O00754-1
	MAN2B1	NM_001440570.1		c.1112G>A	p.Trp371*	stop_gained splice_region	Exon 8 of 24	NP_001427499.1
	MAN2B1	NM_001173498.2		c.1106G>A	p.Trp369*	stop_gained splice_region	Exon 8 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.1109G>A	p.Trp370*	stop_gained splice_region	Exon 8 of 24	ENSP00000395473.2	O00754-1
	MAN2B1	ENST00000221363.9	TSL:1	c.1106G>A	p.Trp369*	stop_gained splice_region	Exon 8 of 24	ENSP00000221363.4	O00754-2
	MAN2B1	ENST00000964003.1		c.1112G>A	p.Trp371*	stop_gained splice_region	Exon 8 of 24	ENSP00000634062.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461888 Hom.: 0 Cov.: 33 AF XY: 0.00000275 AC XY: 2 AN XY: 727244

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53418

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

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic/Likely pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
7	-	-	Deficiency of alpha-mannosidase (7)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
CADD	Pathogenic	54
DANN	Uncertain	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.95
FATHMM_MKL	Pathogenic	0.99	D
PhyloP100		7.4
Vest4		0.45
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=1/199	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.85
SpliceAI score (max)		0.71		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.71		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs786204715; hg19: chr19-12769242;