Acid Maltase Deficiency is categorized into three forms, depending on age of onset and progression of symptoms. Severe muscle weakness occurs. Enlargement of the heart, liver, and tongue also occurs. Mental ability is not affected. Respiratory and heart complications cause death by the age of 18 months.
Muscle weakness is progressive with the respiratory muscles most critically affected.
The heart and liver are usually not involved. Life expectancy is to the second decade. Onset of symptoms generally occurs between the third and fourth decades of life. The most common cause of death for victims of AMD is respiratory and cardiac failure due to massive amounts of glycogen that accumulate in the respiratory and heart muscles. Without research, an untimely death for its victims is inevitable.