No cures for lysosomal storage diseases are known, and treatment is mostly symptomatic, although bone marrow transplantation and enzyme replacement therapy (ERT) have been tried with some success. ERT can minimize symptoms and prevent permanent damage to the body. In addition, umbilical cord blood transplantation is being performed at specialized centers for a number of these diseases. In addition, substrate reduction therapy, a method used to decrease the production of storage material, is currently being evaluated for some of these diseases. Furthermore, chaperone therapy, a technique used to stabilize the defective enzymes produced by patients, is being examined for certain of these disorders. The experimental technique of gene therapy may offer cures in the future.

Ambroxol has recently been shown to increase activity of the lysosomal enzyme glucocerebrosidase, so it may be a useful therapeutic agent for both Gaucher disease and Parkinson's disease. Ambroxol triggers the secretion of lysosomes from cells by inducing a pH-dependent calcium release from acidic calcium stores. Hence, relieving the cell from accumulating degradation products is a proposed mechanism by which this drug may help.

A cure does not exist for I-Cell disease/Mucolipidosis II disease. Treatment is limited to controlling or reducing the symptoms that are associated with this disorder. Nutritional supplements, particularly iron and vitamin B12, are often recommended for individuals with I-Cell disease. Physical therapy to improve motor delays and speech therapy to improve language acquisition are treatment options. Surgery can remove the thin layer of corneal clouding to temporarily improve the complication. It is possible that bone marrow transplant may be helpful in delaying or correcting the neurological deterioration that occurs with I-Cell disease.. Even though there is no existing treatment, the Yash Gandhi Foundation is a 501(c)(3) non-profit organization focused on funding research for I-Cell disease

There is no cure for Pseudo-Hurler Polydystrophy/Mucolipidosis IIIA. Treatment is limited to controlling or reducing symptoms associated with this disorder. Physio-therapy, particularly hydrotherapy has proven effective at relieving muscle stiffness and increasing mobility. The use of crutches, a wheelchair or scooters are treatment options as the metabolic bone disease progresses. The insertion of rods in the spine to stabilize the vulnerable areas can treat scoliosis. Heart valve replacement surgery may be necessary as this disorder progresses.

Currently there is no cure for these disorders. Medical care is directed at treating systemic conditions and improving the person's quality of life. Physical therapy and daily exercise may delay joint problems and improve the ability to move.

Changes to the diet will not prevent disease progression, but limiting milk, sugar, and dairy products has helped some individuals experiencing excessive mucus.

Surgery to remove tonsils and adenoids may improve breathing among affected individuals with obstructive airway disorders and sleep apnea. Sleep studies can assess airway status and the possible need for nighttime oxygen. Some patients may require surgical insertion of an endotrachial tube to aid breathing. Surgery can also correct hernias, help drain excessive cerebrospinal fluid from the brain, and free nerves and nerve roots compressed by skeletal and other abnormalities. Corneal transplants may improve vision among patients with significant corneal clouding.

Enzyme replacement therapy (ERT) are currently in use or are being tested. Enzyme replacement therapy has proven useful in reducing non-neurological symptoms and pain. Currently BioMarin Pharmaceutical produces enzyme replacement therapies for MPS type I and VI. Aldurazyme is an enzymatic replacement therapy for alpha-L-iduronidase produced by BioMarin for use in Type I MPS. In July 2006, the United States Food and Drug Administration approved a synthetic version of I2S produced by Shire Pharmaceuticals Group, called Elaprase, as a treatment for MPS type II (Hunter syndrome).

Bone marrow transplantation (BMT) and umbilical cord blood transplantation (UCBT) have had limited success in treating the mucopolysaccharidoses. Abnormal physical characteristics, except for those affecting the skeleton and eyes, may be improved, but neurologic outcomes have varied. BMT and UCBT are high-risk procedures and are usually performed only after family members receive extensive evaluation and counseling.

For information on clinical trials visit Clinical Trials Search

There is no specific treatment to this disorder. However, several symptoms may be alleviated. For instance, anemia is treated by iron supplements. Some of the movement deficiencies may be corrected with orthopedic intervention. The corneal clouding can be, at least, temporarily corrected by corneal transplantation.

"See the equivalent section in the main mucolipidosis article.

The majority of patients is initially screened by enzyme assay, which is the most efficient method to arrive at a definitive diagnosis. In some families where the disease-causing mutations are known and in certain genetic isolates, mutation analysis may be performed. In addition, after a diagnosis is made by biochemical means, mutation analysis may be performed for certain disorders.

Mucolipidosis type I (ML I) or sialidosis is an inherited lysosomal storage disease that results from a deficiency of the enzyme alpha-N -acetyl neuraminidase (sialidase). The lack of this enzyme results in an abnormal accumulation of complex carbohydrates known as mucopolysaccharides, and of fatty substances known as mucolipids. Both of these substances accumulate in bodily tissues.

Pseudo-Hurler polydystrophy, also referred to as mucolipidosis III (ML III), is a lysosomal storage disease closely related to I-cell disease (ML II). This disorder is called Pseudo-Hurler because it resembles a mild form of Hurler syndrome, one of the mucopolysaccharide (MPS) diseases.

MPS II, Hunter syndrome or iduronate sulfatase deficiency, is caused by lack of the enzyme iduronate sulfatase. Hunter syndrome has two clinical subtypes and (since it shows X-linked recessive inheritance) is the only one of the mucopolysaccharidoses in which the mother alone can pass the defective gene to a son. The incidence of Hunter syndrome is estimated to be 1 in 100,000 to 150,000 male births.

Mucolipidosis (ML) is a group of inherited metabolic disorders that affect the body's ability to carry out the normal turnover of various materials within cells.

When originally named, the mucolipidoses derived their name from the similarity in presentation to both mucopolysaccharidoses and sphingolipidoses. A biochemical understanding of these conditions has changed how they are classified. Although four conditions (I, II, III, and IV) have been labeled as mucolipidoses, type I (sialidosis) is now classified as a glycoproteinosis, and type IV (Mucolipidosis type IV) is now classified as a gangliosidosis.

Inclusion-cell (I-cell) disease, also referred to as mucolipidosis II (ML II), is part of the lysosomal storage disease family and results from a defective phosphotransferase (an enzyme of the Golgi apparatus). This enzyme transfers phosphate to mannose residues on specific proteins. Mannose 6 phosphate serves as a marker for them to be targeted to lysosomes within the cell. Without this marker, the proteins are instead excreted outside the cell—the default pathway for proteins moving through the Golgi apparatus. Lysosomes cannot function without these proteins, which function as catabolic enzymes for the normal breakdown of substances (e.g. oligosaccharides, lipids, and glycosaminoglycans) in various tissues throughout the body (i.e. fibroblasts). As a result, a buildup of these substances occurs within lysosomes because they cannot be degraded, resulting in the characteristic I-cells, or "inclusion cells". These cells can be identified under the microscope. In addition, the defective lysosomal enzymes normally found only within lysosomes are instead found in high concentrations in the blood.

Mucolipidosis type IV (ML IV or ML4) is an autosomal recessive lysosomal storage disorder. Individuals with the disorder have many symptoms including delayed psychomotor development and various ocular aberrations. The disorder is caused by mutations in the MCOLN1 gene, which encodes a non-selective cation channel, mucolipin1. These mutations disrupt cellular functions and lead to a neurodevelopmental disorder through an unknown mechanism. Researchers dispute the physiological role of the protein product and which ion it transports.

Other diseases that result from a deficiency in the sialidase enzyme are categorized in a broader group known as sialidoses. Because ML I is classified as a sialidosis, it is sometimes referred to as sialidosis type II.

A rarer form of sialidosis – sialidosis type 1– occurs in children and adolescents and is often referred to as the juvenile form of the disorder. Children usually begin to show symptoms during the second decade of life, and myoclonus and cherry-red macules are often the initial symptoms. Patients usually develop seizures and progressive deterioration of coordinated muscular and mental activities.

The diagnosis of ML is based on clinical symptoms, a complete medical history, and certain laboratory tests.