In the context of MPS, glycosaminoglycans (GAG) are stored in the supporting and connective tissue. Affected individuals have typical facial changes, bone malformations, short stature, hirsutism, developmental impairment, heart problems, hepatosplenomegaly, visual and hearing impairment. The enzyme replacement therapy used can significantly improve the course of the disease. Furthermore, bone marrow or stem cell transplantation is also used.

This metabolic disorder is a progressive lysosomal storage disease caused by α-mannosidase deficiency. As a result, the breakdown of mannose-containing oligosaccharides in the body cells is disturbed. Currently, two causal therapies are available: Hematopoietic stem cell transplantation and enzyme replacement therapy of a recombinant form of human α-mannosidase. Indications for testing: facial dysmorphia, recurrent infections, hearing impairment, mental impairment, developmental delay, hepatosplenomegaly, macroglossia, skeletal malformations, gait disorder. Affected children require close follow-up with infection management, early intervention, hearing aids, sports, and orthopedic surgery.

Of the ten known forms, CLN1 and CLN2 disease are tested for. Affected individuals experience a progressive degenerative disease of the brain. Clinically, this disorder presents with loss of mental abilities to dementia, speech disorders, epilepsy, and retinal degeneration with vision loss and increased mortality. CLN1 manifests in both neonatal and young adulthood, CLN2 belongs to the late infantile form. A gene therapy is currently being tested for CLN1 disease. CLN2 disease, also known as tripeptidyl peptidase 1 (TPP1) deficiency, involves intracerebroventricular infusion therapy in infancy.

In Pompe disease, type II glycogenosis occurs due to acid maltase deficiency. In the infantile form, the fetus already has hypertrophic cardiomyopathy, hepatomegaly, and muscle hypotonia. These children are conspicuous postnatally for respiratory failure and drinking difficulties. The late-onset form is a degenerative metabolic myopathy. Here, the progressive limb-girdle myopathies typically stand out, beginning in the lower limbs, and/or with respiratory problems due to deposits in the respiratory muscles. Since 2006, this disease can be successfully treated by specific enzyme replacement therapy.

With this enzyme deficiency, fats cannot be properly broken down, and cholesterol esters and triglycerides are deposited in the tissues. This causes hepatosplenomegaly to cirrhosis, xanthomatosis and atherosclerosis. The earlier this progressive disease manifests, the worse the prognosis. Withearly onset,adrenal calcification, liver failure, diarrhea/steatorrhea, malabsorption, and mental impairment are prominent. Later manifestations also include bleeding in the gastrointestinal tract, coronary artery disease, aneurysm, and stroke. Blood products are administered for anemia and low platelets. Liver transplantation is also used here. Therapeutically, blood lipid-lowering drugs are available. In addition, there is specific enzyme replacement therapy.

Here, a gene mutation causes an enzyme defect in sterol 27-hydroxylase. This leads to neurodegenerative disorder due to deposition of cholestanol as well as cholesterol in the tissues. The typical clinical presentation includes gallbladder pathologies, cholestasis and chronic diarrhea in infants, cataract with visual disturbances, xanthomas, psychiatric or neurological disorders, developmental disorders, epilepsy, cardiomyopathy with cardiac arrhythmias. Various drug therapies are already available for this disease. The treatment leads to normalization and partial regression of symptoms that have already occurred.

In this congenital enzyme defect, a disorder occurs in the area of erythrocyte metabolism. Infection, ingestion of certain drugs or foods can cause hemolytic anemia and even kidney failure. Newborns are conspicuous with jaundice.