The incidence in Sweden is 1 per 80,000 live born babies. Eventually as the syndrome becomes more widely known among the physicians, more patients, until now without the correct diagnose, will be transferred to this group. In addition to that a contribution of newly born children with the syndrome is to be expected from parents unaware of being in the risk zone. It is therefore probable that a whole group of new inherited diseases is characterised by carbohydrate-deficient glycoproteins. The basic biochemical error is not yet fully understood, but it involves a disturbance in the ability of the cells to produce complete carbohydrate chains of glycoproteins, which among other things are important in the body for the transport of proteins.
Glycoproteins contain chains of usually four different carbohydrates.
Mannose, being one of these carbohydrates, is needed for the other three to be combined. The four clinical stages. The first three years can be most serious and life threatening. During this period the symptoms can be mild, but most infants experience serious involvement of internal organs. Mental retardation may be moderate or severe.