Background

Neuroacanthocytosis (NA) syndromes are rare diseases affecting only 1 in 3 million inhabitants and have been defined by neurological abnormalities in combination with misshaped acanthocytic red blood cells. NA syndromes are characterized by a wide variety of dysfunction of the nervous system including epileptic seizures and basal ganglia-related movement disorder symptoms, dementia, psychosis and speech/swallowing difficulties leading to a markedly reduced life-span (1-3). So far, only fairly effective symptomatic treatment is available for NA syndromes. The core NA syndromes are McLeod syndrome (MLS), pantothenate kinase-associated neurodegeneration (PKAN) and Chorea-acanthocytosis (ChAc) (1, 3-5). ChAc is caused by mutations within the gene VPS13A encoding for the protein named Chorein. Due to their rarity, studies on the molecular pathophysiology of these diseases are seldom. Any new insight in the molecular biology of this disease is however a prerequisite to novel innovative treatment approaches.

Within the E-Rare program 2009 the “European Multidisciplinary Initiative on Neuroacanthocytosis – EMINA-1“ has been funded to study the clinical picture of NA syndromes and the effect of innovative treatment options on the one hand and to reveal the enigmatic connection between malformed red blood cells and neurodegeneration on the other hand. This transnational consortium has made major steps towards the characterization of the various different NA syndromes and detailed phenotypic descriptions and tissue banking of most NA syndromes are now available for these rare diseases (3). Although the EMINA-1 network was focused on clinical/translational aspects, within the basic research groups of EMINA-1 major progress has been made in ChAc by demonstrating an increased Lyn kinase activity (6) and decreased RAC1 activity with impaired actin polymerization (7). These kinases might be suitable drug targets for novel therapies.

 

Literature:

1. A. Danek et al., Mov Disord 16, 882 (Sep, 2001).

2. C. Dobson-Stone et al., Ann Neurol 56, 299 (Aug, 2004).

3. H. H. Jung, A. Danek, R. H. Walker, Orphanet J Rare Dis 6, 68.

4. A. Al-Asmi et al., Epilepsia 46, 1256 (Aug, 2005).

5. C. Dobson-Stone et al., Neurogenetics 6, 151 (Sep, 2005).

6. L. De Franceschi et al., Blood 118, 5652 (Nov 17).

7. M. Foller et al., FASEB J. 26(4): 1526-1534 (2012)