This meeting, which aimed at integrating Asian thinking and experience into the European and North American work on chorea-acanthocytosis (ChAc) and McLeod syndrome (MLS), the core neuroacanthocytosis syndromes, was proposed by Prof Akira Sano (Kagoshima) and organized by Shinji Saiki (Cambridge), Ruth Walker (New York) and Adrian Danek (Munich). The truly international meeting brought together neurologists, psychiatrists, haematologists and basic scientists from Asia, Australia, Europe and North America. Taking place in Kyoto, the meeting featured many local Japanese contributions, which have been outstanding during the past quarter century.

Participants of the 2006 symposium contributed to
Walker RH, Saiki S, Danek A, Neuroacanthocytosis Syndromes II, Springer, Heidelberg, New York, Berlin to be published beginning of 2008

Ruth Walker reviewed existing knowledge. The genetic flaws that cause both ChAc and MLS are now understood. The affected genes code for proteins, known as chorein in ChAc and XK in MLS. Genes contain the code, which makes the proteins, which control all functions in the body. The problem is that in spite of the genetic discoveries, now 5 and 12 years ago, respectively, the function of both these proteins is still not understood. Since the two diseases are quite similar, we presume that these two proteins may be components of one single pathway in the body. While the major clinical problem is obviously in the nervous system, the red blood cell offers a ready line of investigation in a much simpler, but easily accessible, type of cell.

Antonio Velayos-Baeza and Clothilde Leveque in Oxford, UK are trying to understand the function of the chorein protein. There are major technical difficulties. By protein standards, chorein is very large, roughly 5 times as big as a typical protein. Standard techniques are difficult to apply and progress is slow, but it will come.

Soohee Lee in New York has studied the way in which the family of XK proteins is distributed in different human cells. According to haematologist Lucia de Franceschi from Verona, many proteins in McLeod membranes are abnormally susceptible to modification with phosphate groups.

Hans Jung in Zurich, who has extensively studied MLS patients in Switzerland, noted the similarity of the XK protein to an example in a well-studied worm known as Caenorhabditis elegans. Genetic problems, which disable the protein in this worm, interfere with the programming of cell lifespan.

Masayuki Nakamura from Prof Sano´s group in Kagoshima reported on their development of a mouse in which the chorein gene is disabled: the mouse shows a condition similar to ChAc. This is a faithful model, mimicking the human disease fairly closely. This will be extremely useful for preliminary trials of potential medications. Mac Ho (Singapore) who had discovered the XK gene has developed a parallel mouse for MLS.

Akira Sano (Kagoshima, Japan) who studies the psychiatric problems in ChAc, characterised different clinical presentations that may allow other doctors better to recognise the condition, to avoid misdiagnosis of neuroacanthocytosis patients as ‘purely psychic’. This should lead to better treatment of these troublesome symptoms.

Shinji Saiki (Cambridge, UK), reported on a study of muscles from patients with movement disorders, ChAc and MLS included.