Endosomal recycling defects link Huntington's disease with McLeod syndrome.

Chhetri and colleagues (2022. J. Cell Biol.https://doi.org/10.1083/jcb.202112073) show that Rab11-mediated endosomal recycling regulates cell surface expression of McLeod syndrome protein XK. Mutant huntingtin interferes with the recycling of XK to the cell surface and significantly reduces manganese transport across cell membrane.

Interaction between VPS13A and the XK scramblase is important for VPS13A function in humans.

VPS13 family proteins form conduits between the membranes of different organelles through which lipids are transferred. In humans, there are four VPS13 paralogs, and mutations in the genes encoding each of them are associated with different inherited disorders. VPS13 proteins contain multiple conserved domains. The Vps13 adaptor-binding (VAB) domain binds to adaptor proteins that recruit VPS13 to specific membrane contact sites. This work demonstrates the importance of a different domain in VPS13A function. The pleckstrin homology (PH) domain at the C-terminal region of VPS13A is required to form a complex with the XK scramblase and for the co-localization of VPS13A with XK within the cell. Alphafold modeling was used to predict an interaction surface between VPS13A and XK. Mutations in this region disrupt both complex formation and co-localization of the two proteins. Mutant VPS13A alleles found in patients with VPS13A disease truncate the PH domain. The phenotypic similarities between VPS13A disease and McLeod syndrome caused by mutations in VPS13A and XK, respectively, argue that loss of the VPS13A-XK complex is the basis of both diseases.

Orofacial manifestations of chorea-acanthocytosis: case presentation and literature review.

Chorea-acanthocytosis is a rare neurological disorder that produces involuntary body movements, along with a condition of misshapen red blood cells that is characterized by appearing in early adulthood. There are numerous orofacial manifestations linked to chorea-acanthocytosis that the dental practitioner must consider in early and late stages of the disease, such as chronic oral ulcerations, chronic mouth grinding, difficulty swallowing, and biting the lip and tongue, among others. This case, the first to the authors' knowledge to address the area of orofacial pain, provides general signs and symptoms of the disorder and management following a multidisciplinary approach. The life span of patients with this disorder is generally shortened, and correct management is essential to improve the quality of life.

Cardiac manifestation is evident in chorea-acanthocytosis but different from McLeod syndrome.

INTRODUCTION: We aimed to study the various cardiac manifestations of the two core neuroacanthocytosis (NA) syndromes, namely chorea-acanthocytosis (ChAc) and McLeod syndrome (MLS). So far, cardiac involvement has been described as specific feature only for MLS. METHODS: We studied six patients with ChAc (mean age 44.5 years, five men, one woman) and six patients with MLS (mean age 57.1 years, all men). Cardiac evaluation included echocardiography and/or cardiac magnetic resonance imaging (cardiac MRI), 24-h ECG-recording and examination of cardiac biomarkers. RESULTS: Cardiac involvement of ChAc was found in four of six patients. Two patients showed mildly reduced left ventricular ejection fraction (LVEF), two other patients mild to moderate left ventricular (LV) dilatation. Neither an increase in ventricular ectopic beats nor ventricular tachycardia were evident in ChAc. Four of five MLS patients showed left ventricle dilatation and reduced left ventricular ejection fraction (LVEF). Two of these, in addition, had critical ventricular tachycardia. High sensitive troponin T was elevated in all patients, for whom data were available (n = 10). In contrast, elevation of high sensitive troponin I was found in one of six ChAc and one of two MLS patients. CONCLUSION: For the first time, we reveal cardiac involvement in a cohort of six ChAc patients, while the risk to develop heart failure seems lower than in MLS. Our study confirms the malignant nature of MLS in terms of ventricular arrhythmias and progression to advanced heart failure. Herein, we define disease-specific recommendations for cardiac assessment in both conditions.

[Early Diagnosis of Chorea-Acanthocytosis: Orofacial Dyskinesia, Epileptic Seizures, and HyperCKemia]. / Frühdiagnose der Chorea-Akanthozytose: orofaziale Dyskinesien, epileptische Anfälle und HyperCKämie.

Chorea-acanthocytosis is an uncommon neurodegenerative disorder. Early diagnosis is often challenging. The triad of orofacial dyskinesia, epileptic seizures, and hyperCKemia should alert neurologists of a neuroacanthocytosis syndrome. The diagnosis can be confirmed by detection of chorein deficiency or through molecular genetics (VPS13A mutation).

Neuroacantocitosis, una nueva mutación / Neuroacanthocytosis: a new mutation

No disponible

[Epilepsy revealing chorea-acanthocytosis: about a case]. / Epilepsie révélant une chorée-acanthocytose: à propos d'un cas.

Chorea-acanthocytosis (ChAc) is an extremely rare autosomal recessive disorder caused by mutations in the VSP13A gene on chromosome 9q21. It is characterized by neurological symptoms, psychiatric manifestations and multisystem involvement resulting in myopathy, axonal neuropathy and presence of spiculated red blood cells or acanthocytes. Rarely, epilepsy may be the early symptom in these patients. This can lead to serious delays in diagnosis. We here report the case of a patient with this disease who had seizures several years before the onset of typical manifestations.

Hipometabolismo estriatal detectado por PET-FDG cerebral en un caso de corea-acantocitosis / Brain FDG-PET showing striatal hypometabolism in a case of chorea-acanthocytosis

No disponible

Seizures as presenting and prominent symptom in chorea-acanthocytosis with c.2343del VPS13A gene mutation.

OBJECTIVE: The aim of the study was to characterize the clinical features of nine patients in three families with chorea-acanthocytosis (ChAc) sharing the same rare c.2343del mutation in the VPS13A gene. METHODS: Genetic test results, clinical description, magnetic resonance imaging (MRI), and electroencephalography (EEG), as well as laboratory results are summarized. RESULTS: ChAc is a rare genetic disorder characterized by hyperkinetic movements, seizures, cognitive decline, neuropsychiatric symptoms, and acanthocytes on peripheral blood smear. This unique cohort of nine patients is characterized by seizures as a first and prominent symptom. In our patients, other features of ChAc appeared later, including tics, other movement disorders, dysarthria, and mild to moderate cognitive decline. SIGNIFICANCE: Patients with chorea-acanthocytosis carrying the described rare mutation can present with focal, treatment-resistant seizures.

Successful Combination of Pallidal and Thalamic Stimulation for Intractable Involuntary Movements in Patients with Neuroacanthocytosis.

OBJECTIVE: Neuroacanthocytosis (NA) is a rare neurodegenerative disease that involves severe involuntary movements including chorea, dystonia, and trunk spasms. Current treatments are not effective for these involuntary movements. Although there are a few reports on the use of deep brain stimulation to treat patients with NA, the optimal stimulation target is not yet definitive. Some authors have reported successful improvement of NA symptoms with stimulation of the globus pallidum interna, and others have reported a reduction in trunk spasm with stimulation of the ventralis oralis complex of the thalamus. We investigated whether the optimal target is well defined for NA. METHODS: We describe the effect of combination stimulation of the globus pallidum interna and the ventralis oralis complex of the thalamus in 2 patients with NA who presented with severe intractable involuntary movements. RESULTS: Gpi stimulation alone was an insufficient effect for trunk spasm and/or chorea. Vo complex stimulation given without Gpi stimulation resulted in improvement of trunk spasm after 2 weeks and might also have had an incomplete effect on involuntary movement including a chorea. The combination of Gpi and Vo complex stimulation reduced the trunk spasms and chorea. This improvement was maintained at 3 months after surgery. The Unified Huntington's Disease Rating Scale score at 1 year after surgery was lower than that before surgery. CONCLUSIONS: Gpi stimulation appears to be insufficient to control violent involuntary movements; therefore, combined GPi and Vo complex stimulation provided some moderate advantage over Gpi stimulation alone.