Human gene for torsion dystonia located on chromosome 9q32-q34.

Torsion dystonia is a movement disorder of unknown etiology characterized by loss of control of voluntary movements appearing as sustained muscle contractions and/or abnormal postures. Dystonic movements can be caused by lesions in the basal ganglia, drugs, or gene defects. Several hereditary forms have been described, most of which have autosomal dominant transmission with variable expressivity. In the Ashkenazi Jewish population the defective gene frequency is about 1/10,000. Here, linkage analysis using polymorphic DNA and protein markers has been used to locate a gene responsible for susceptibility to dystonia in a large, non-Jewish kinship. Affected members of this family have a clinical syndrome similar to that found in the Jewish population. This dystonia gene (ITD1) shows tight linkage with the gene encoding gelsolin, an actin binding protein, and appears by multipoint linkage analysis to lie in the q32-q34 region of chromosome 9 between ABO and D9S26, a region that also contains the locus for dopamine-beta-hydroxylase.

Dopamine beta-hydroxylase activity in cerebrospinal fluid of idiopathic torsion dystonia.

Since a postmortem biochemical study and a genetic linkage study of idiopathic torsion dystonia suggested possible involvement of dopamine beta-hydroxylase (DBH), we determined CSF DBH activities of Jewish and non-Jewish patients with childhood-onset idiopathic torsion dystonia and found no differences from a control population.

Phenotypic expression of X-linked dystonia-parkinsonism (lubag) in two women.

Lubag (X-linked dystonia-parkinsonism) has been considered a sex-linked recessive trait and has been mapped to the pericentromeric region of the X chromosome. We studied a 54-year-old man with lubag and two of his female first cousins. Genetic typing was carried out using X chromosome markers. Fluorodopa PET was performed on the man and one of the women. The man had moderately severe parkinsonism and dystonia. A 61-year-old female first cousin had mild left-sided dystonia and her 54-year-old sister had mild generalized chorea. Genetic typing data revealed that all three inherited an X chromosome with marker alleles strongly associated with lubag. Cytologic analysis did not reveal evidence of X chromosomal deletion. Fluorodopa PET in both the man and one affected cousin revealed reduced striatal uptake rate constants consistent with nigrostriatal involvement. These observations suggest that lubag may be a codominant disorder and that it is possible for women to be affected.

A study of idiopathic torsion dystonia in a non-Jewish family: evidence for genetic heterogeneity.

A gene (DYT1) for idiopathic torsion dystonia (ITD) was mapped to chromosome 9q34 in non-Jewish and Jewish families; the dystonia in these families usually began in childhood, with the limb muscles affected first. The role of the DYT1 gene in adult-onset and cervical- or cranial-onset ITD is unknown. We examined 53 individuals from four generations of a non-Jewish North American family with adult-onset ITD. There were seven affected family members, with a mean age at onset of 28.4 years (range, 7 to 50 years). In six of the seven, the neck was affected first. All seven developed cervical dystonia, and dysarthria or dysphonia occurred in five. Linkage data excluded the region containing the DYT1 locus, indicating that DYT1 was not responsible for ITD in this family. This study provides evidence that a gene other than DYT1 is responsible for some cases of adult cervical-onset dystonia.

Palliative care for people with late-stage Huntington's disease.

Huntington's disease provides a unique model to examine issues of long-term and palliative care for a younger and more mobile population who remain institutionalized longer than other nursing home residents. A lack of community-based alternatives for young families, and the need for highly complex care planning encourage long term care placement mid-way in the disease process. Despite the need for a body of knowledge specific to environmental enrichment and therapeutic strategies for improving quality of life for people in the later stages of Huntington's disease, there is no published data in the neurological or rehabilitation literature. This article reviews the signs and symptoms and offers a multidisciplinary approach to ameliorate problems frequently encountered in caring for this population.

The primary dystonias of childhood.

Dystonia refers to a specific clinical entity as well as movements occurring as a result of other syndromes. Dystonic movements are the most commonly misdiagnosed abnormal involuntary movements. Dystonia worsens under emotional or physical stress and with fatigue, lessens with rest, relaxation, hypnosis and sensory tricks, can have diurnal fluctuations and may disappear in sleep. Dystonia is often confused with chorea and myoclonus and considered to be voluntary, that is, psychogenic in origin, in part because of its unusual and varied clinical expression. The neuroscience nurse, cognizant of the natural history, phenomenology and genetics of dystonia, will be able to identify early signs and symptoms, inform colleagues and teach family members who care for children with primary dystonia.

Proposed guidelines for videotaping individuals with movement disorders.

Standardized rating scales for Parkinson's disease and dystonia have been validated and are now widely accepted as useful clinical assessment tools. However, the other movement disorders have been more difficult to quantify. The use of a standardized videotape protocol can provide a more precise audiovisual record of the movement disorder patient. With broader use by others and further revisions, these guidelines can be improved in order to provide an accurate assessment and teaching tool. The authors welcome comments.

Adductor laryngeal breathing dystonia in a patient with lubag (X-linked dystonia-Parkinsonism syndrome).

We report a patient with Lubag (X-linked dystonia-parkinsonism) who presented with severe respiratory stridor from adductor laryngeal breathing dystonia. Emergency tracheostomy was necessary, and subsequent laryngeal injection with botulinum toxin led to worsening aspiration. Botulinum toxin injection for severe lingual dystonia was successful.

Distant effects of locally injected botulinum toxin: a double-blind study of single fiber EMG changes.

We used single fiber electromyography (SFEMG) to study 42 patients who had enrolled in a double-blind, placebo-controlled trial undertaken to assess the efficacy of botulinum toxin (BTX) injection of neck muscles to treat torticollis. SFEMG in a limb muscle was performed before treatment, 2, and 12 weeks after injection of placebo or BTX. Before treatment, the mean jitter was 26.8 microsec in patients who were to receive BTX, and 25.7 microsec in the placebo group. Two weeks after injection, mean jitter in the group receiving BTX was 43.6 microsec. In the placebo group, it was 26.5 microsec (P = less than .05). Twelve weeks after injection, mean jitter in the BTX group was 35.5; for the placebo group it was 24.5. Fiber density did not change in any patient during the study. There were no remote clinical effects of BTX. Injection of BTX into muscles affected with focal dystonia is a promising and safe treatment, but there are subclinical effects on uninjected muscles.

Genetic mapping of "Lubag" (X-linked dystonia-parkinsonism) in a Filipino kindred to the pericentromeric region of the X chromosome.

"Lubag" is an X-linked disorder causing dystonia and parkinsonism that has only been described in families from the Philippines, principally from the island of Panay. We have established linkage between the disease phenotype "lubag" and DNA markers which span the Xp11.22-Xq21.3 region by using a large Filipino family with 8 affected men in three generations. These DNA markers define an interval of about 20 centimorgans in the pericentromeric region of the X chromosome as the most likely site of the disease locus XDPD (X-linked dystonia-parkinsonism). XDPD has a maximum multipoint log likelihood ratio score (Zmax) of about 4.6 over the interval from Xq12 to Xq21.31 (DXS159-DXYS1X). The co-occurrence of dystonia and parkinsonism in lubag and in other known disorders suggests there may be a common pathogenetic mechanism. Identification of the genetic defect in this family may provide an important clue toward understanding the pathogenesis and pathophysiology of both dystonia and parkinsonism.