A pedigree of amyotrophic chorea with acanthocytosis

Untangling the Thorns: Advances in the Neuroacanthocytosis Syndromes

There have been significant advances in neuroacanthocytosis (NA) syndromes in the past 20 years, however, confusion still exists regarding the precise nature of these disorders and the correct nomenclature. This article seeks to clarify these issues and to summarise the recent literature in the field. The four key NA syndromes are described here-chorea-acanthocytosis, McLeod syndrome, Huntington's disease-like 2, and pantothenate kinase- associated neurodegeneration. In the first two, acanthocytosis is a frequent, although not invariable, finding; in the second two, it occurs in approximately 10% of patients. Degeneration affecting the basal ganglia is the key neuropathologic finding, thus the clinical presentations can be remarkably similar. The characteristic phenotype comprises a variety of movement disorders, including chorea, dystonia, and parkinsonism, and also psychiatric and cognitive symptoms attributable to basal ganglia dysfunction. The age of onset, inheritance patterns, and ethnic background differ in each condition, providing diagnostic clues. Other investigations, including routine blood testing and neuroimaging can be informative. Genetic diagnosis, if available, provides a definitive diagnosis, and is important for genetic counseling, and hopefully molecular therapies in the future. In this article I provide a historical perspective on each NA syndrome. The first 3 disorders, chorea-acanthocytosis, McLeod syndrome, Huntington's disease-like 2, are discussed in detail, with a comprehensive review of the literature to date for each, while pantothenate kinase-associated neurodegeneration is presented in summary, as this disorder has recently been reviewed in this journal. Therapy for all of these diseases is, at present, purely symptomatic.

Clinical and molecular research of neuroacanthocytosis

Neuroacanthocytosis is an autosomal recessive or dominant inherited disease characterized by widespread, non-specific nervous system symptoms, or spiculated "acanthocytic" red blood cells. The clinical manifestations typically involve chorea and dystonia, or a range of other movement disorders. Psychiatric and cognitive symptoms may also be present. The two core neuroacanthocytosis syndromes, in which acanthocytosis is atypical, are autosomal recessive chorea-acanthocytosis and X-linked McLeod syndrome. Acanthocytes are found in a smaller proportion of patients with Huntington's disease-like 2 and pantothenate kinase-associated neurodegeneration. Because the clinical manifestations are diverse and complicated, in this review we present features of inheritance, age of onset, neuroimaging and laboratory findings, as well as the spectrum of central and peripheral neurological abnormalities and extraneuronal involvement to help distinguish the four specific syndromes.

Neuroacanthocytosis: new developments in a neglected group of dementing disorders

Neurological abnormalities associated with spiculated, "acanthocytic" red cells in blood have been summarized as neuroacanthocytosis. This is a heterogeneous group of conditions that can now be clearly subdivided on the basis of genetic discoveries. The core neuroacanthocytosis syndromes are autosomal recessive chorea-acanthocytosis (ChAc) and the X-linked McLeod syndrome (MLS). Huntington's disease-like 2 (HLD2) and pantothenate kinase associated neurodegeneration (PKAN) can now also be included. All of these share dyskinesias, cognitive deterioration and progressive neurodegeneration mainly of the basal ganglia, but they are sufficiently distinct to permit a specific working diagnosis on the basis of clinical, laboratory and imaging findings. In addition, the VPS13A (formerly called CHAC), XK, JPH3 and PANK2 genes, respectively, may be examined for mutations. Unfortunately, little is yet known about the normal and abnormal physiology of the protein products of these genes, but they appear to be involved in membrane function and intracellular protein sorting. Since no cures are yet available, development and study of disease models in experimental animals (mouse, C. elegans) is a priority for current research. From a clinical point of view, the common occurrence of cardiomyopathy in MLS, the transfusion hazards due to the McLeod Kell phenotype and the possibility of improving the violent trunk spasms and orofacial dyskinesias typical for ChAc (with subsequent lip or tongue mutilations and feeding dystonia) by deep brain surgery or stimulation should be considered in patient management.

Chorea-acanthocytosis associated with tourettism

We report on a case of Chorea-acanthocytosis (ChAc) in association with Tourettism that consisted of motor and vocal tics, attention deficit-hyperactivity disorder, and obsessive-compulsive disorder in addition to the typical symptoms of ChAc. The subject was compared with his elder sister who had the same disease but milder clinical profile and neuroradiological findings. The [(18)F]-2-fluoro-2-deoxyglucose positron emission tomography (FDG-PET) findings did not explain the differences in symptomatology between the patient and his sister, although they may have correlated with severity.

Severe generalized dystonia due to primary putaminal degeneration: case report and review of the literature

Putaminal lesions of a variety of etiologies may cause secondary dystonia. We report on a case of primary putaminal degeneration as a cause of severe childhood-onset generalized dystonia and review the literature of the pathology of dystonia. A 44-year-old patient with severe generalized childhood-onset dystonia and macrocephaly underwent neurological evaluation and neuropathological examination. Neurological examination was normal apart from dystonia and signs referable to prior cryothalamotomy. Workup for metabolic and genetic causes of dystonia was negative. Neuroimaging showed severe bilateral putaminal degeneration, which subsequently correlated with the neuropathological findings of gliosis, spongiform degeneration, and cavitation. The substantia nigra pars compacta contained a normal number of neurons but decreased tyrosine hydroxylase immunoreactivity. There were no histopathological markers of other metabolic or degenerative diseases.

[Neuroacanthocytosis. A case report]

We present a 45 years old man with neuroacanthocytosis. This gentleman has complex partial seizures and generalized tonic-clonic seizures, as well as movement disorders characterized by chorea and orofacial diskinesia. Complementary examination shows acanthocytosis of 11% on peripheral blood, irritative focus on right temporal lobe on EEG, serum creatinokinase of 101 U/l and volume reduction and hypersignal on caudate nucleus and putamen bilaterally on MRI.

Late appearance of acanthocytes during the course of chorea-acanthocytosis

A case of chorea-acanthocytosis (CA) syndrome is described. The presence of acanthocytes has usually been considered an important diagnostic marker of CA. However, it is not specific and other neurological diseases have to be considered. In the present report we rule out other diagnostic possibilities and show that the acanthocytes in the peripheral blood smears can appear even later during the course of the disease.

Chorea-acanthocytosis: genetic linkage to chromosome 9q21

Chorea-acanthocytosis (CHAC) is a rare autosomal recessive disorder characterized by progressive neurodegeneration and unusual red-cell morphology (acanthocytosis), with onset in the third to fifth decade of life. Neurological impairment with acanthocytosis (neuroacanthocytosis) also is seen in abetalipoproteinemia and X-linked McLeod syndrome. Whereas the molecular etiology of McLeod syndrome has been defined (Ho et al. 1994), that of CHAC is still unknown. In the absence of cytogenetic rearrangements, we initiated a genomewide scan for linkage in 11 families, segregating for CHAC, who are of diverse geographical origin. We report here that the disease is linked, in all families, to a 6-cM region of chromosome 9q21 that is flanked by the recombinant markers GATA89a11 and D9S1843. A maximum two-point LOD score of 7.1 (theta = .00) for D9S1867 was achieved, and the linked region has been confirmed by homozygosity-by-descent, in offspring from inbred families. These findings provide strong evidence for the involvement of a single locus for CHAC and are the first step in positional cloning of the disease gene.

The neuropathological features of neuroacanthocytosis

In this article we describe the neuropathological changes in three patients with neuroacanthocytosis and review the neuropathology of the other eight cases reported in the literature. Macroscopically the brains showed enlargement of the lateral ventricles, especially the frontal horns. The most severely and consistently affected brain areas were the caudate nucleus and putamen, which were atrophic and showed by light microscopy marked neuronal loss and gliosis. Small and medium-sized striatal neurons were particularly depleted. The globus pallidus was almost as severely involved as the striatum. In some cases the thalamus, substantia nigra, and anterior horns of the spinal cord showed pathology, mainly neuronal loss and mild gliosis. Brain areas with no pathology included the subthalamic nucleus, cerebral cortex, cerebellum, pons, and medulla. The preservation of these areas may help in the neuropathological distinction of neuroacanthocytosis from Huntington's disease.

[Homologies between membrane proteins result in expected or unexpected relations between neuromuscular and erythrocyte diseases]

The advances achieved in biochemistry and molecular genetics have made it possible to demonstrate that the membrane proteins of the erythrocytes belong to protein "families" that are present in most cell membranes and share remarkable structural and functional homologies. Abnormalities of erythrocyte membrane proteins might then totally or partially reflect lesions of other cell membranes that are intrinsically more severe than those of the erythrocytes. Examples of these physiopathogenetic links can be found in congenital diseases where muscular and erythrocytic pathologies coexist. Such are: (1) choreaacanthocytosis supported by molecular abnormalities of the so-called band 3 protein or anion channel; (2) Mac Leod syndrome by deficiency of a membrane protein precursor of Kell antigens; (3) some cases of hereditary spherocytosis associated with qualitative and quantitative ankyrin alterations. Yet, despite the homologies that are known to exist between spectrin and dystrophin, all attempts to use spectrin analysis as marker of Duchenne-Becker muscular dystrophy have met with complete failure, which shows that at this early stage one should refrain from drawing firm physiopathological conclusions from the available data.

Chorea-acanthocytosis: abnormal composition of covalently bound fatty acids of erythrocyte membrane proteins

Phospholipid class, peak profile of each phospholipid class, loosely bound fatty acids, covalently (tightly) bound fatty acids of the erythrocyte membranes, and plasma fatty acids were investigated using high-performance liquid chromatography in six patients with chorea-acanthocytosis and 14 age- and sex-matched normal control subjects. Additionally, six patients with Huntington's disease were included as disease control subjects in the study of covalently bound fatty acids. Study of covalently (tightly) bound fatty acids in erythrocyte membrane proteins after alkaline hydrolysis, hitherto undescribed in chorea-acanthocytosis, revealed that palmitic acid (C16:0) was significantly increased and stearic acid (C18:0) was decreased in the patients with chorea-acanthocytosis. Analyses for total covalently bound fatty acids disclosed that palmitic and docosahexaenoic (C22:6) acids were increased and stearic acid was decreased in chorea-acanthocytosis. Phospholipid class (phosphatidylcholine, phosphatidylethanolamine, sphingomyelin, and phosphatidylserine) and peak profile of each phospholipid class from the erythrocyte membranes did not differ between the patients with chorea-acanthocytosis and the control subjects. Of the loosely bound fatty acids, linoleic acid (C18:2) was significantly decreased in those with chorea-acanthocytosis, which seemed to be nonspecific.

Chorea-acanthocytosis: report of a family and neuropathological study of two cases

We report three siblings, offspring of normal consanguineous parents, with a progressive neurological illness that began in midlife and was characterized primarily by chorea and leading to death in the fourth decade. The proband had erythrocyte acanthocytosis with normal serum beta-lipoprotein. Biopsy of left gastrocnemius muscle showed neurogenic muscular atrophy. There was a decrease in the numbers of large myelinated axons of the sural nerve. Postmortem examination of two cases showed marked atrophy, neuronal loss and gliosis of the caudate nucleus and putamen. Autosomal recessive inheritance is likely in this family.

Peripheral neuropathy in amyotrophic chorea-acanthocytosis

We investigated involvement of the peripheral nervous system in 6 patients with amyotrophic chorea-acanthocytosis. Electromyographic and neurographic findings, and pathological changes as demonstrated by examination of biopsy specimens of muscle and sural nerve indicate that most patients had an axonal sensorimotor polyneuropathy with more pronounced involvement of the distal portion of the nerves. Results obtained in one patient raised the question of an anterior horn cell disorder.

Self-injurious behaviour and the Gilles de la Tourette syndrome: a clinical study and review of the literature

Thirty (33%) of 90 patients with the Gilles de la Tourette syndrome exhibited self-injurious behaviour. Fourteen were head bangers, of whom two had cavum septum pellucidum. Clinical correlates of self-injury were the severity of Gilles de la Tourette syndrome symptoms and psychopathology, with special reference to obsessionality and hostility. We discuss an additional patient who died from a subdural haematoma as a result of head banging, and three who had permanent vision impairment from self inflicted eye injuries.

Neurochemical findings in neuroacanthocytosis

We performed a neurochemical study of the brain of two unrelated patients, living in different continents, with neuroacanthocytosis. The levels of monoamines and their metabolites, gamma-aminobutyric acid and substance P, were measured in several brain areas and the monoamine metabolites in cerebrospinal fluid. The binding of 3H-spiperone to striatal membranes and to lymphocytes was also measured. Both patients had a progressive neurological disorder with onset in the third decade of life and characterized by a complex movement disorder, epilepsy, muscular wasting, and changes in behavior. The movement disorder initially manifested with oromandibular dystonia and limb chorea, but at the time of death was characterized by a severe dystonic syndrome. The chemical changes were similar in the two patients. The most important neurochemical findings were a depletion of dopamine and its metabolites in most brain areas, most notably in the striatum, and elevation of norepinephrine levels in the putamen and globus pallidus. Substance P was markedly reduced in the striatum and substantia nigra. Our findings may provide clues to the neurochemical mechanisms underlying dystonia.

Chorea-acanthocytosis: a report of three new families and implications for genetic counselling

Chorea-acanthocytosis (CHA) is a rare inherited neurologic disorder with peripheral red cell acanthocytes and normal serum lipoprotein levels. To date, 8 families with the disorder have been reported outside of Japan. We describe 4 patients in 3 families with CHA and review the clinical presentations in previous reports. In addition, we report magnetic resonance imaging scans in these patients. The pattern of inheritance in these families is most likely autosomal recessive. Obligate heterozygotes do not have acanthocytes on wet preparation under phase microscope. Two of 3 propositi were initially diagnosed as having Huntington chorea. Chorea-acanthocytosis is an important differential in the diagnosis of Huntington chorea and should be considered in families without a family history. The paucity of families with CHA reported to date may represent lack of recognition.

Hereditary myoclonus and chorea: the spectrum of hereditary nonprogressive hyperkinetic movement disorders

We report three members of a single family who developed a newly described combination of myoclonus and chorea in association with mild ataxia. The occurrence of this and related syndromes suggests that inherited, slowly progressive myoclonus, chorea, and dystonia, alone or in combination, should be viewed as a spectrum of hyperkinetic involuntary movements, and that each motor component may represent variable expression of the same genetic defect.

Amyotrophic choreo-acanthocytosis: a new observation in southern Europe

Amyotrophic choreo-acanthocytosis is a rare disease of adult onset characterized by dyskinesias, neurogenic muscular atrophy, erythrocytary acanthocytosis with normal serum lipoproteins and elevated levels of serum CPK. Presumably, this disorder is an autosomal recessively inherited trait. This disease has been described in Japanese, English, Finnish and Puerto Rican people. This is the first observation in the southern countries of Europe, in two members of a Calabrian family. The authors point out that amyotrophic features can occur several years before the appearance of the extrapyramidal disorders.

Evoked potentials in choreoacanthocytosis

Visual, brain-stem auditory and somatosensory evoked potentials were obtained in two patients with choreoacanthocytosis. Only minor SSEP amplitude reduction was found in one patient. Therefore evoked potentials were not helpful in identifying patients with symptoms of this disorder of up to 8 years duration.

Erythrocyte membrane abnormalities in patients with amyotrophic chorea with acanthocytosis. Part 1. Spin labeling studies and lipid analyses

Low fluidity was observed in the erythrocyte membranes of familial chorea-acanthocytosis by spin labeling with 12NS. The high content of the saturated fatty acids support the finding of low fluidity. Other lipid contents (cholesterol and phospholipids) and the cholesterol/phospholipid ratio were within normal ranges. The sharp decrease in the parameter, (h0/h-1)1/2, suggests phase separation deep inside the patients' erythrocyte membrane matrix. This distortion of the membrane matrix may be caused by membrane components other than the lipid components.

A new X-linked syndrome comprising progressive basal ganglion dysfunction, mental and growth retardation, external ophthalmoplegia, postnatal microcephaly and deafness

We report on 4 boys (3 in one family) who have a remarkably constant syndrome of childhood-onset choreoathetosis with later spasticity, postnatal microcephaly, growth and mental retardation, apparent external ophthalmoplegia and varying degrees of deafness. The pedigrees are consistent with X-linked inheritance. The syndrome is compared and contrasted with others comprising basal ganglion dysfunction in childhood. It is concluded that clinically and genetically the condition is unique.

Chorea-acanthocytosis. Neurological disease with acanthocytosis

A case of chorea-acanthocytosis (CA) syndrome is described. CA is a rare, inherited syndrome characterized by normolipoproteinemic acanthocytosis and progressive neurological disturbances (orofacial dyskinesia, limb chorea, lip and tongue biting, distal muscle wasting, muscle hypotonia, absent or diminished tendon reflexes) with adult onset. Thus far, 10 independent reports of CA have been published. The present case is the first patient reported in Europe outside Great Britain. Due to obvious clinical similarities between CA and Huntington's chorea, particular attention is drawn to the differential diagnosis between these 2 syndromes. Investigation of the red blood cell morphology should necessarily be performed in the examination of choreic patients, particularly when the disorder is familial.