In this first part of our four-part series on alpha-mannosidosis, we feature Laura Buch, a physician assistant who practices medical genetics at the Greenwood Genetic Center in South Carolina. Laura’s work focuses on the diagnosis and treatment of patients with abnormal newborn screens, inborn errors of metabolism, and lysosomal storage disorders. She also cares for alpha-mannosidosis patients.Alpha-mannosidosis is a rare genetic disorder characterized by a deficiency of the enzyme alpha-D-mannosidase. Alpha-mannosidosis is best thought of as a continuum of disease that is generally broken down into three forms: a mild, slowly progressive form (type 1); a moderate form (type 2); and a severe, often rapidly progressive and potentially life-threatening form (type 3).The symptoms and severity of the disorder are highly variable. Signs may include distinctive facial features, skeletal abnormalities, hearing loss, intellectual disability, and dysfunction of the immune system. Alpha-mannosidosis is caused by mutations of the MAN2B1 gene. This genetic mutation is inherited as an autosomal recessive trait.