MAN1B1

Chr 9AR

mannosidase alpha class 1B member 1

Also known as: ERMAN1, ERManI, MANA-ER, MRT15

NCBI Gene: 11253 ENSG00000177239 UniProt: Q9UKM7 OMIM: 604346

This gene encodes an alpha-1,2-mannosidase that trims mannose residues from N-linked glycans in the endoplasmic reticulum, functioning in glycoprotein quality control and targeting misfolded proteins for degradation. Biallelic mutations cause Rafiq syndrome, an autosomal recessive intellectual disability disorder. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.83), suggesting some tolerance to heterozygous disruption.

OMIM ResearchSummary from RefSeq, OMIM, UniProt

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]

OMIM ResearchGenerating clinical summary…