Mannosidosis is a rare genetic disorder caused by a deficiency of the enzyme alpha-mannosidase. This enzyme is essential for breaking down certain complex sugars in the body. When it is not functioning properly, these sugars accumulate in cells, leading to various health issues. Symptoms of mannosidosis can vary but often include developmental delays, intellectual disability, and physical abnormalities. The condition is inherited in an autosomal recessive pattern, meaning that a child must inherit two copies of the faulty gene, one from each parent, to develop the disorder.