Schindler disease, also known as Kanzaki disease and Alpha-N-acetylgalactosaminidase deficiency is a rare congenital metabolic disorder in humans. This lysosomal storage disorder is caused by a deficiency in the enzyme alpha-NAGA (alpha-N-acetylgalactosaminidase), attributable to mutations in the NAGA gene on chromosome 22,which leads to excessive lysosomal accumulation of glycoproteins.A deficiency of the alpha-NAGA enzyme leads to an accumulation of glycosphingolipids throughout the body. This accumulation of sugars gives rise to the clinical features associated with this disorder.
Infants with Schindler disease tend to die within 4 years of birth, therefore, treatment for this form of the disease is mostly palliative. However, Type II Schindler disease, with its late onset of symptoms, is not characterized by neurological degeneration. There is no known cure for Schindler disease, but bone marrow transplants have been trialed, as they have been successful in curing other glycoprotein disorders.
From Madisons Foundation:
What Schindler disease is an extremely rare genetic disorder that occurs in young children and causes severe injury to the nervous system. It is a member of a family of disorders known as lysosomal storage diseases. In diseases such as these, the body lacks a particular enzyme, causing certain carbohydrates and proteins to build up in cells. This build up of storage material interferes with the normal function of the cell and can lead to cell death. In Schindler disease, the body lacks an enzyme known as alpha-N-acetylgalactosaminidase (alpha-GalNAc). There is a separate, but similar, genetic disorder known as Kanzaki disease that affects adults and is often compared to Schindler disease in medical textbooks and journal articles.
Who Very little information is known at this point about how often Schindler disease occurs. Fewer than 20 children worldwide have ever been diagnosed with the disorder. Schindler disease is a genetic disease, so individuals with one family member with the disorder are at an increased risk of having others with it. As a result, several of the children who have been diagnosed with Schindler disease have been found to have siblings or other relatives with the disorder.-------------------------------
Another non-medical source of information is The International Advocate for Glycoprotein Storage Diseases.
Rare Disease Day is February 28, 2013.