chr9-137087074-C-CG

Variant names:

• chr9-137087074-C-CG
• rs1190243291
• NM_016219.5:c.79dupG

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_016219.5(MAN1B1):​c.79dupG​(p.Ala27GlyfsTer35) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000207 in 1,450,440 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: MAN1B1 NM_016219.5 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.413
• Publications: 0 publications found

Genes affected

MAN1B1 (HGNC:6823): (mannosidase alpha class 1B member 1) This gene encodes an enzyme belonging to the glycosyl hydrolase 47 family. This enzyme functions in N-glycan biosynthesis, and is a class I alpha-1,2-mannosidase that specifically converts Man9GlcNAc to Man8GlcNAc isomer B. It is required for N-glycan trimming to Man5-6GlcNAc2 in the endoplasmic-reticulum-associated degradation pathway. Mutations in this gene cause autosomal-recessive intellectual disability. Alternative splicing results in multiple transcript variants. A related pseudogene has been identified on chromosome 11. [provided by RefSeq, Dec 2011]

MAN1B1 Gene-Disease associations (from GenCC):

• MAN1B1-congenital disorder of glycosylation

  Inheritance: AR Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• Rafiq syndrome

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• autosomal recessive non-syndromic intellectual disability

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 48 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-137087074-C-CG is Pathogenic according to our data. Variant chr9-137087074-C-CG is described in ClinVar as Pathogenic. ClinVar VariationId is 632038.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_016219.5. 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
	MAN1B1	NM_016219.5	MANE Select	c.79dupG	p.Ala27GlyfsTer35	frameshift	Exon 1 of 13	NP_057303.2	Q9UKM7
	MAN1B1	NR_045720.2		n.94dupG		non_coding_transcript_exon	Exon 1 of 13
	MAN1B1	NR_045721.2		n.94dupG		non_coding_transcript_exon	Exon 1 of 14

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	MAN1B1	ENST00000371589.9	TSL:1 MANE Select	c.79dupG	p.Ala27GlyfsTer35	frameshift	Exon 1 of 13	ENSP00000360645.4	Q9UKM7
	MAN1B1	ENST00000371587.9	TSL:1	n.79dupG		non_coding_transcript_exon	Exon 1 of 14	ENSP00000483132.2	A0A087X064
	MAN1B1	ENST00000544448.6	TSL:1	n.79dupG		non_coding_transcript_exon	Exon 1 of 13	ENSP00000444966.2	H0YGV7

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 0.00000207 AC: 3 AN: 1450440 Hom.: 0 Cov.: 31 AF XY: 0.00000278 AC XY: 2 AN XY: 720578

African (AFR) AF: 0.00 AC: 0 AN: 33404

American (AMR) AF: 0.00 AC: 0 AN: 43126

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25654

East Asian (EAS) AF: 0.00 AC: 0 AN: 39314

South Asian (SAS) AF: 0.00 AC: 0 AN: 84238

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50752

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5672

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1108392

Other (OTH) AF: 0.0000167 AC: 1 AN: 59888

GnomAD4 genome Cov.: 34

Alfa AF: 0.0000843 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Inborn genetic diseases (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		0.41
Mutation Taster		=18/182	disease causing (fs/PTC)

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

Other links and lift over

dbSNP: rs1190243291; hg19: chr9-139981526;