Predicted to enable mannose-1-phosphate guanylyltransferase activity. Predicted to be involved in GDP-mannose biosynthetic process; cell wall mannoprotein biosynthetic process; and protein glycosylation. Predicted to be active in cytoplasm. Human ortholog(s) of this gene implicated in autosomal recessive limb-girdle muscular dystrophy type 2T; congenital muscular dystrophy-dystroglycanopathy A14; and muscular dystrophy-dystroglycanopathy. Orthologous to human GMPPB (GDP-mannose pyrophosphorylase B). [provided by Alliance of Genome Resources, Apr 2022]