HOUSTON Families of children who died of Canavan disease, a rare degenerative brain disease, are suing the hospital and researchers who used their children's blood and tissue to identify and patent the gene responsible for the disorder. The six-count lawsuit filed on October 30 is believed to be the first of its kind. It alleges breach of informed consent, breach of fiduciary duty, unjust enrichment, fraudulent concealment and misappropriation of trade secrets.

Canavan disease most commonly afflicts children of Jewish families whose ancestors came from eastern and central Europe. There are about 200 children in the US with Canavan disease. Symptoms usually appear when babies are 3–6 months old. Patients are never able to walk or eat independently. As the disease progresses, children often lose most of their sight and are prone to seizures and infection. They develop difficulty chewing and swallowing; most eventually require intravenous feeding. Children become less responsive over time but are never totally unresponsive. Most die between the ages of 10 and 15.

Canavan disease is caused by a deficiency of the enzyme aspartoacylase, which leads to increased excretion of N-acetylaspartic acid (NAA). These abnormally high levels of NAA lead to demyelination and spongy degeneration of the brain causing the neurological features of Canavan disease. No cure is known.

The story begins in 1987 when Daniel Greenberg and his wife, parents of two children with Canavan disease, convinced Dr Reuben Matalon to try to identify the gene responsible for the disease and develop affordable carrier and prenatal testing. The research began when the Greenbergs provided Matalon with numerous blood and urine samples from their children. They located other affected families and arranged for them to provide urine, skin and even post-mortem tissue samples to Matalon. They established the first ever Canavan Registry that provided listings of families with a history of the disease and what autopsy tissues had been preserved and stored. This registry was crucial to Matalon's research. The Canavan Foundation persuaded Canavan families to give blood, tissue, urine and autopsy samples, as well as financial support to Matalon.

Matalon's team, which relocated to Miami Children's Hospital (MCH), identified the Canavan gene in 1993 and developed accurate prenatal and carrier screening. Without informing any of the Canavan families and organisations, the defendants filed a patent in 1994 for the gene and for carrier and prenatal testing. In 1996, the Canavan Foundation offered free Canavan testing in New York.

After the patent (US 5,679,635) issued in 1997, the American College of Obstetricians and Gynecologists recommended that all Jewish women of central and eastern European descent be tested to determine if they are Canavan carriers. In 1999, however, MCH began to enforce its patent and collect royalties for the patented genetic test. MCH says this is necessary to recover some of the $5 million spent developing the test. The licensing fees were too expensive for the Canavan Foundation and the organisation was forced to stop offering free genetic screening. In addition, MCH set a limit on the number of tests any academic lab could perform.

The outcome of the lawsuit could have wide-ranging implications. Thousands of gene patent applications are pending before the US Patent and Trade Office (see 'Patent knowledge' BioMedcentral 20 November 2000).