Structure-function relationships of band 3 variants

This review describes many of the naturally occurring band 3 variants that have been reported in the literature to date; from the common band 3 Memphis, to the rare band 3 HT. Both the molecular basis of these variants, and their effect on the structure and/or function of band 3, are described. The blood group antigens that have recently been assigned to band 3, such as Diego, Wright, Waldner, Redelberger and Warrior, are mentioned. Band 3 variants that affect the morphology of the red cell (e.g. acanthocytosis in band 3 HT and stomatocytic ovalocytosis in band 3 SAO) are described, as are many of the band 3 mutations that cause instability, either at the mRNA or protein level, and hence hereditary spherocytosis (HS). Band 3 variants that affect the binding pocket of the anion transport inhibitor, 4,4'-diisothiocyanato-2,2'-dihydrostilbene disulphonic acid (H2DIDS), (e.g. Diego and band 3 HT) and band 3 variants that affect the rate of anion transport (e.g. band 3 HT and band 3 in red cells that lack glycophorin A (GPA)) are reviewed in greater detail. The association between band 3 and GPA is discussed; both with respect to the Wright antigens and with regards the structure/function of band 3 in the absence of GPA.

Acanthocytosis, retinitis pigmentosa, pallidal degeneration. Report of two cases without serum lipid abnormalities

We describe two unrelated patients with Hallervorden-Spatz, disease characterized by prominent facio-bucco-lingual dyskinesia. Acanthocytosis and retinitis pigmentosa were additional findings. Brain MRI showed the typical 'tiger's eye' image of the globus pallidus. This phenotype closely resembled the so-called HARP syndrome (hypoprebetalipoproteinemia, acanthocytosis, retinitis pigmentosa and pallidal degeneration), but extensive serum lipid study failed to demonstrate any lipoprotein abnormality. Our results raise the question whether HARP syndrome is an autonomous entity or a particular phenotype of Hallervorden-Spatz disease.

[Choreoacanthocytosis. A neurologic-hematologic syndrome]

A 43 year old male patient is reported who presented at the age of 33 years with a hyperkinetic movement disorder. At the time of presentation orofacial dyskinesias, tic-like hyperkinesias with vocalisation and behavioural disturbance dominated the clinical picture. In the course of his illness he developed a marked truncal choreoathetosis and a symmetrical, distal, predominantly motor polyneuropathy with wasting of lower leg muscles. Serum creatinine kinase levels were markedly elevated. Serum lipids and lipoproteins were within normal limits. These clinical features in combination with an increased number of acanthocytes, clearly visible after dilution of whole blood with normal saline (1:1), led to the diagnosis of choreoacanthocytosis (CA). Both parents were neurologically and behaviourally normal, but were found to have acanthocytes in saline diluted whole blood. The literature concerning CA is reviewed.

[Hematuria--diagnostic procedure and therapeutic approaches]

Hematuria is a common clinical problem. It may arise from benign diseases posing minimal risk to the patient to potentially life-threatening conditions. Due to its many causes, the evaluation of hematuria often requires various different diagnostic procedures. To prevent unnecessary diagnostic tests, the workup should begin with noninvasive techniques such as history, urinalysis, laboratory data and ultrasonography. This proceeding allows a simple and rapid differentiation in renal and non-renal causes of hematuria in most cases.

[Cardiac involvement in familial amytrophic chorea with acantocytosis: description of two new clinical cases]

Familial amyotrophic chorea and acanthocytosis, also known as the Levine-Critchley syndrome, is a rare inherited disease characterized primarily by central nervous system involvement with progressive demyelinization and autosomic or dominant transmission. Clinical symptoms include orofaciolingual dyskinesia and involuntary choreiform movements associated with skeletal muscle atrophy due to axonal demyelinization and erythrocyte acanthocytosis. A few patients have some cardiac abnormality, including an electrocardiographic pattern of left ventricular hypertrophy, left atrial wave abnormalities, non-specific ST-T wave changes, and a pseudonecrosis pattern with abnormal Q waves in the inferior leads. Two-dimensional echocardiography has disclosed concentric ventricular hypertrophy and the typical findings of congestive cardiomyopathy. We report the case of two brothers, 40 and 58 years old, who had asymmetric left ventricular hypertrophy (more marked in the younger brother), left ventricular mass index increase unrelated to a hypertensive state or the percent of circulating acanthocytes. Functional systolic parameters were normal. The younger brother had dilation of the aortic root and marked enlargement of the non-coronary Valsalva sinus, and both patients manifested mitral leaflet redundancy without evident prolapse. Our observations suggest the hypothesis that connective tissue and/or vessel muscle-elastic fiber pathology is associated with the well-known neurological disorders typical of the Levine-Critchley syndrome. It is thus advisable that these patients undergo thorough cardiovascular evaluation.

[Disturbance of hypothalamic-pituitary hormone secretion in familial chorea-acanthocytosis]

An endocrinological study was performed dopaminergic regulation of the hypothalamic-pituitary axis of 3 patients with familial chorea-acanthocytosis (females, 38 to 47 years of age). All 3 patients exhibited low basal levels of triiodo-thyronine (T3), and 2 patients had a slightly elevated baseline plasma prolactin (PRL) level. The patients had a delayed plasma thyroid stimulating hormone (TSH) response and plasma PRL excessive response to thyrotropin releasing hormone (TRH), and a low plasma growth hormone releasing hormone (GRF) response to L-dopa. These TSH, PRL and GRF responses represent a secretion pattern due to a hypothalamic disorder, suggesting impaired regulation of hormone secretion by the dopaminergic system, primarily in the hypothalamus. In addition, an increased growth hormone (GH) response secretion following TRH (paradoxical response) was observed in 2 patients, suggesting that the pituitary was also involved. An oral glucose tolerance test (75g-OGTT) revealed a diabetic pattern in all 3 patients, indicating frequent association with impaired glucose tolerance.

Sleep features in Tourette's syndrome, neuroacanthocytosis and Huntington's chorea

Twenty-one patients affected by extrapyramidal disorders were polygraphically recorded during spontaneous nocturnal sleep for two consecutive nights to assess their sleep and movement patterns. The patients (pts) sample included: Gilles de La Tourette syndrome (TS, nine pts), neuroacanthocytosis (NA, six pts) and Hungtington's chorea (HC, six pts). Sleep recording included C3/A2, 01/A2, ROC/LOC, submental EMG, EKG, nasal airflow thoracoabdominal respirogram, bilateral anterior tibialis and other EMGs, in relation to the individual distribution of the abnormal movements. According to our observations, abnormal movements always decreased but never ceased completely during sleep. Sleep efficiency (SE) was nearly always poor with a high percentage of wakefulness after sleep onset (WASO) and increased number of arousals. REM sleep was often reduced and in some cases (3 TS pts) incompletely defined as far as its microstructural aspects. Slow wave sleep (SWS) was reduced in HC, normal in NA, and increased in all TS patients with the exception of the two adult subjects more severely affected, while the percentage of stage 2 was not affected. Spindling was increased in NA, HC and in the two most severely affected adult TS patients.

Inherited movement disorders

A high proportion of neurological diseases characterized by movement disorders are caused by single genes; in others, such as Parkinson's disease, there appears to be a genetic component. Gene mapping studies have made substantial progress in unravelling the aetiology of dystonias and Huntington's disease, and are underway in other disorders such as essential tremor and Gilles de la Tourette syndrome. These advances are already applicable to clinical practice, particularly in Huntington's disease where identification of the disease mutation has led to the possibility of improved diagnosis and more widespread availability of predictive testing for asymptomatic family members.

[Neuro-acanthocytosis with associated myopathy. A case report]

Abnormalities of striated muscle histology in patients with neuroacanthocytosis have been previously attributed to chronic denervation. This hypothesis is based in the presence of axonal peripheral neuropathy. In this 37-year-old patient clinical, biochemical and histologic data revealed a non specific primary myopathy. Other important findings were decreased levels of 5-hydroxy-indoleacetic acid (5-HILA) and homovanillic acid (HVA) in the CSF, cerebellar and basal ganglia atrophy seen in MRI and infertility of probable gonadal origin.

[A case of chorea-acanthocytosis associated with low glycohemoglobin A1c]

We reported the first case of chorea-acanthocytosis associated with low glycohemoglobin A1c. Fasting blood sugar, daily profile of blood sugar, serum fructosamine and 75 g glucose tolerance test were all within normal limits. While abnormal hemoglobins were not detected, red blood cell half-life was sharply reduced to 13.4 days. These findings suggest that the low glycohemoglobin A1c in this case is highly ascribable to the reduction of red blood cell half-life rather than to continuous hypoglycemia. However, we can not rule out that the abnormalities of red blood cell membrane, suggested factors in this disease, may be related to the low glycohemoglobin A1c value. Further investigations on chorea-acanthocytosis cases with normal red blood cell half-life are necessary in order to elucidate whether an abnormal glycohemoglobin A1c value is a specific indication regarding this disease.

McLeod syndrome: a distinct form of neuroacanthocytosis. Report of two cases and literature review with emphasis on neuromuscular manifestations

McLeod syndrome was originally described on the basis of a specific blood group phenotype with weak expression of Kell antigens. This erythrocyte abnormality also causes acanthocytosis. The haematological findings are associated with abnormalities in other organ systems, including neuromuscular manifestations. A 51-year-old patient was followed up for 11 years. He presented with persistent muscle creatine kinase elevation and progressive heart disease and later developed a slowly progressive neuropathy and choreic movements. His younger brother presented with grand mal seizures, involuntary movements and high muscle creatine kinase when aged 43 years. Clinical myopathy was absent in both, yet muscle biopsy showed mild myopathic changes. The presence of a motor axonopathy was supported by electrophysiological findings. One brother also showed sensory axonopathy. The movement disorder suggested accompanying basal ganglia dysfunction. Earlier reports of McLeod syndrome are reviewed with respect to neuromuscular involvement. Absence of the Kx membrane protein seems to be the cause of this multi-system disorder.

[Hypothyroidism and acanthocytes: diagnostic significance of blood smear]

We report on 3 cases of hypothyroidism in which the diagnoses were suspected after having observed acanthocytes on the blood film. The diagnostic value of this erythrocyte change has been neglected, although the results of studies have shown a test specificity of 87-99%, other diseases related to acanthocytes being very rare. After an analysis of the studies and case reports dealing with acanthocytes we conclude that hypothyroidism must be excluded in all cases where acanthocytes are observed on the blood film.

Presynaptic and postsynaptic striatal dopaminergic function in neuroacanthocytosis: a positron emission tomographic study

Using [18F]dopa, [11C]raclopride, C15O2, and positron emission tomography, we have assessed striatal dopamine storage capacity, dopamine D2-receptor integrity, and regional cerebral blood flow, respectively, of 6 patients with neuroacanthocytosis. The patients with neurocanthocytosis all had chorea and variable combinations of seizures, dementia, axonal neuropathy, and orolingual self-multiation. [18F]dopa positron emmission tomographic findings were compared with 30 normal controls and 16 patients with sporadic, L-dopa-responsive, Parkinson's disease. Caudate and anterior putamen [18F]dopa uptake were normal in patients with neuroacanthocytosis, but mean posterior putamen [18F]dopa uptake was reduced to 42% of normal, similar to that in patients with Parkinson's disease. In patients with neuroacanthocytosis, mean equilibrium caudate: cerebellum and putamen: cerebellum [11C]raclopride uptake ratios were reduced to 54% and 62% of normal, compatible with a 65% and 53% loss of caudate and putamen D2-receptor-binding sites, respectively. Striatal and frontal blood flow was also depressed. The severe loss of D2-receptor-bearing striatal neuron, with concomitant loss of dopaminergic projections from the nigra to the posterior putamen, is consistent with both chorea and extrapyramidal rigidity being features of patients with neuroacanthocytosis.

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.

Acanthocytosis associated with myelodysplasia

Dysplastic hematopoiesis associated with erythrocyte macrocytosis is a morphologic hallmark of myelodysplasia. We report the cases of six patients with myelodysplasia in which acanthocytosis was the predominant red blood cell (RBC) abnormality. In each case acanthocytes represented 5% to 10% of circulating RBC forms and was the primary reason for referral in two cases. None of the patients had comorbid conditions known to be associated with acanthocyte formation. Myelodysplasia should be considered in the differential diagnosis of acanthocytosis, particularly in the anemic, elderly individual. Acanthocytosis may be a harbinger of an unrecognized, hematologic stem-cell disorder.

Choreoacanthocytosis in a Chinese patient--a case report

A 50-year old Chinese woman with the rare neurological disorder of Choreoacanthocytosis is described. Her illness is characterised by seizures, buccolingual dyskinesia, choreiform movements, arreflexia and mild sensorimotor polyneuropathy. Acanthocytes were present in her peripheral blood in large numbers but the serum lipid profile was normal. Her features are consistent with those so far described in Caucasian and Japanese patients. The disease differs from Huntington's chorea in that there are acanthocytes, peripheral neuropathy, and metal function remains relatively intact.

Regional brain glucose metabolism in neuroacanthocytosis

Two brothers with neuroacanthocytosis had [18F]-2-fluoro-2-deoxyglucose PET scans showing marked glucose hypometabolism of the caudate and putamen. MRIs showed no evidence of atrophy or modification of signal intensity in these structures. Decreased glucose utilization of the striatum can underlie hyperkinetic movement disorders of various etiologies.

Chorea-amyotrophy with chronic hemolytic anemia: a variant of chorea-amyotrophy with acanthocytosis

We studied two siblings with chorea and amyotrophy of adult onset and spherocytic hemolytic anemia. Autopsy revealed an atrophic striatum with iron deposition and spheroid bodies. Degeneration of the substantia nigra and spinal cord anterior horns was seen without iron deposition. The disorder seems to be a variant of the chorea-amyotrophy-acanthocytosis syndrome, and the pathology may account for evidence of parkinsonism and amyotrophy in that syndrome. Acanthocytosis may not be the only hematologic abnormality in this disorder.