Dopamine beta-hydroxylase gene excluded in four subtypes of hereditary dystonia

The gene for familial dystonia with myoclonic jerks responsive to alcohol is not located on the distal end of 9q

A gene (DYT1) for susceptibility to early-onset torsion dystonia in Ashkenazi Jewish and Gentile kindreds is situated on chromosome 9q32-q34 in a 6-7 cM span between markers AK1 and ASS. To determine whether transmission of familial dystonia with myoclonic jerks responsive to alcohol was consistent with a gene in this region, we studied the 37 members of a Swedish family, of whom 20 were so affected. A lod score of < -2.00 from a two-point linkage analysis with six DNA markers covering a 30 cM span from D9S26 to D9S10 that included the region of the DYT gene indicated that this gene is not located in this region, and that two or more autosomal loci are responsible for hereditary dystonia in humans.

Linkage mapping of dopa-responsive dystonia (DRD) to chromosome 14q

Dopa-responsive dystonia (DRD) is an autosomal-dominant neurological disorder which appears to result from a genetically determined deficiency of striatal dopamine. Pathological evidence suggests that this may be due to the establishment of a reduced number of dopaminergic nerve terminals in the striatum, or to an excessive reduction (pruning) of these terminals in early development. We have mapped the DRD gene to chromosome 14 by linkage analysis in 3 families with a maximum 2-point lod score of 4.67 at 8.6 centiMorgans from D14S63; maximum multipoint lod scores > 6 were obtained for the intervals D14S47-D14S52 and D14S52-D14S63. The flanking loci D14S47 and D14S63 define a region of about 22 cM as containing the DRD gene.

Early onset dystonia decreasing with development. Case report of two children with familial myoclonic dystonia

Two related girls had the onset of unilateral leg dystonia in the neonatal period and at 13 months, respectively. The dystonic signs subsided with motor development and resolved completely in one of the girls by the age of 5 years. There was no response to L-dopa. From 2-3 years of age segmental myoclonus with a shoulder girdle distribution appeared. Family investigation results were compatible with autosomal dominant myoclonic dystonia responsive to alcohol. The onset and resolution of dystonia have not been described previously. This disorder is genetically separate from torsion dystonia. No linkage has been found to the dopamine beta-hydroxylase gene locus. Genetically determined disorders of neurotransmission may add to our knowledge of the normal development of motor control and thus merit further study.

The autosomal dominant dystonias

Dystonia is a term used to describe a specific set of abnormal movements that can occur as a symptom of a variety of neurologic disorders, but also as a disease entity in its own right. This review focuses on the primary dystonias and delineates the genetic contribution to these disorders. Included is a description of the well recognized forms of primary dystonias which manifest autosomal dominant inheritance, especially the "classic" type of early onset, generalized torsion dystonia, but also other clinically distinct forms such as myoclonic dystonia, paroxysmal dystonia, and DOPA-responsive dystonia. Also, a summary of the molecular genetic studies pertinent to these disorders and a discussion of the implications of recent genetic research for delineating the wide spectrum of this phenotypically and genetically heterogeneous group of diseases are forthcoming.