19-12647517-G-T

Position:

• chr19-12647517-G-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000528.4(MAN2B1):​c.2746C>A​(p.Arg916Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R916C) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: MAN2B1 NM_000528.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 3.26

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]

ENSG00000269242 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a chain Lysosomal alpha-mannosidase E peptide (size 128) in uniprot entity MA2B1_HUMAN there are 7 pathogenic changes around while only 1 benign (88%) in NM_000528.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr19-12647517-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
MAN2B1	NM_000528.4	c.2746C>A	p.Arg916Ser	missense_variant	22/24	ENST00000456935.7	NP_000519.2
MAN2B1	NM_001173498.2	c.2743C>A	p.Arg915Ser	missense_variant	22/24		NP_001166969.1
MAN2B1	XM_005259913.3	c.2749C>A	p.Arg917Ser	missense_variant	22/24		XP_005259970.1
MAN2B1	XM_047438841.1	c.1645C>A	p.Arg549Ser	missense_variant	15/17		XP_047294797.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
MAN2B1	ENST00000456935.7	c.2746C>A	p.Arg916Ser	missense_variant	22/24	1	NM_000528.4	ENSP00000395473.2
ENSG00000269242	ENST00000597692.1	n.304C>A		non_coding_transcript_exon_variant	2/5	2		ENSP00000470240.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461806 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727212

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D;.
Eigen	Pathogenic	0.85
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Benign	0.74	D
LIST_S2	Uncertain	0.94	D;D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.99	D;D
MetaSVM	Uncertain	0.76	D
MutationAssessor	Pathogenic	4.0	H;.
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-5.6	D;D
REVEL	Pathogenic	0.85
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	D;.
Vest4		0.98
MutPred		0.95		Loss of sheet (P = 0.0357);.;
MVP		0.92
MPC		0.93
ClinPred		1.0	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.96
gMVP		0.97

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

Publications

LitVar

Other links and lift over

dbSNP: rs864621990; hg19: chr19-12758331;