Progress of genetics and diagnosis of primary dystonia / 上海交通大学学报（医学版）

Dystonia is one kind of dyskinesia characterized by abnormal movement and/or posture caused by persistent or intermittent muscle contraction. It also has distinguished features of repeatability and modeling, and can be induced or aggravated by random movements. Dystonia caused by hereditary factors is named as primary dystonia. Currently, 28 phenotypes have already been found in primary dystonia. Development of genetic technology has largely promoted the discovery of genetic mechanisms. Even so, many patients still have different genetic and clinical features from these phenotypes. Diagnosis of primary dystonia is quite challenging. Clinical manifestations, imaging examinations, electromyography, gene testing and other examinations should be taken into account for systematic diagnosis. This article reviews the genetic progress and diagnostic strategies of primary dystonia, aimed at providing help for further clinical practice and scientific research.

Analysis of DYT1 and DYT6 in Thai patients with primary dystonia

@# DYT1 and DYT6 dystonias are the two most common genetic primary dystonias. However, they are rare in the Asian population and have never been reported in Thailand. DYT6 dystonia typically presents with craniosegmental dystonia with speech involvement, whereas DYT1 dystonia typically presents with lower limb dystonia, which tends to become generalized over time. Methods: Blood samples were collected from 14 patients with primary dystonia evaluated in five tertiary hospitals in Thailand. Genotyping of the TOR1A and THAP1 gene was performed. Results: Two patients were found to have a missense mutation, p.M143V (c.427A>G), in exon 3 of the THAP1 gene confirming the diagnosis of DYT6 dystonia. One patient was a woman who developed blepharospasm and lower cranial dystonia at the age of 38 years. Her dystonia spread to the neck and arm six months later. The other patient developed focal hand dystonia at the age of 34 years. The TOR1A mutation was not identified in any of these 14 patients.

Clinical View Points on Primary Dystonia and Dystonia-plus Syndrome

Dystonia is a disorder of movement caused by involuntary, sustained muscle contractions affecting one or more sites of body, frequently causing twisting and repetitive movements, or postures. Dystonic movements and postures can produce a wide range of clinical presentations. Some distinguishing clinical features of dystonia can help the appropriate diagnosis of primary dystonia. The direction of contraction is almost consistent. Action dystonia and occupational dystonia are related to a movement or task-specific movement, respectively. Sensory tricks or gestes antagonistes are usually seen in patients with dystonia. Two types of tremors can be seen in patients with dystonia: a postural and/or action tremor that resembles essential tremor and a rhythmic expression of dystonic tremor. Sometimes dystonic tremor appears to be less regular and can be associated with myoclonus. Onset age of dystonia, body distribution and etiologies are important to correct diagnosis of primary dystonia. It is well known that the age of onset has important prognostic implications. This article highlights general concepts of phenomenology, classification that are relevant for the purpose a clinical diagnosis.

Study on the gene mutation of spinocerebellar ataxia types 1～3 in patients with primary dystonia / 临床神经病学杂志

Objective To study the gene mutation of the spinocerebellar ataxia(SCA) types 1～3 in the patients with primary dystonia.Methods The CAG triplet repeat expansion of SCA1～3 were detected with the polymerase chain reaction(PCR) in two patients with primary dystonia(father and son) and their 21 health family members.Results The two patients with primary dystonia were found to have the gene mutation of SCA3,the CAG repeat were 80 and 75 respectively.The gene mutations of SCA1,2 were not found in the two patients.The gene mutation of SCA1～3 were not found in the 21 family members.Conclusions The patients with primary dystonia have the gene mutation of SCA3.The gene mutations of SCA3 may be relatived to the incidence of primary dystonia.