Alcohol‐responsive myoclonic dystonia in a large family: Dominant inheritance and phenotypic variation

Abstract

Alcohol-responsive myoclonic dystonia is reported in 26 individuals in a six-generation family, thus indicating autosomal dominant inheritance. Twenty affected family members aged between 3 and 56 years were examined on one occasion. Myoclonus in arms, shoulder, and neck distribution was seen in 17, with occasional generalized jerks in 14. Leg dystonia/hemidystonia was seen in two infant cases, writer's cramp in seven, torticollis/retrocollis in two, and finger tremor in three. The onset of myoclonus was regularly reported from 2 to 3 years of age, the onset of leg dystonia/hemidystonia from 6 to 18 months of age, writer's cramp from early school age, and neck dystonia from late teenage. The effect of alcohol had been noted in 10 individuals, and seven of them abused alcohol. Once established, the neurological signs did not progress significantly. Leg dystonia resolved in two juvenile members. Two adult members had recovered from myoclonus: one elderly man and one posthemorrhagic spastic hemiplegic man. Extensive family investigation is necessary to clarify the clinical variation of this autosomal dominant disorder of involuntary movements.

Essential myoclonus and myoclonus dystonia

“…In these families, myoclonus may occur alone or associated with dystonia or sometimes tremor. Isolated dystonia (as initial hemidystonia) was reported in two infants, shortly preceding the appearance of myoclonus, but had largely disappeared by the age of 3 years (26). Of 15 family members reported by Korten et al (27), eight had myoclonus alone; four, myoclonus and tremor; and three, tremor alone.…”

Fine Localization of the Torsion Dystonia Gene (DYT1) on Human Chromosome 9q34: YAC Map and Linkage Disequilibrium

“…Kramer, unpubl.). Genes responsible for other hereditary types of dystonia, including rapid-onset (Dobyns et al 1993), myoclonic (Kurlan et al 1988;Kyllerman et al 1990), and other late-onset focal dystonias (Forsgren et al 1988;Bressman et al 1994a) have not been mapped yet.…”

Association of a missense change in the D2 dopamine receptor with myoclonus dystonia

“…A 3-bp deletion in the DYT1 gene causes the majority of cases of early-onset primary torsion dystonia (7), and linkage to the DYT1 locus has been excluded in several families with MD (8,9), including the one under study (data not shown). Despite the description of various large families with MD in the literature (3,(8)(9)(10)(11)(12)(13), as yet, no positive linkage has been reported to a chromosomal location.…”

“…In addition, the DRD2 receptor is believed to have a role in affect, emotion, and reward mechanisms (14) and has been implicated in the etiology of alcoholism (20,21) and schizophrenia (22). Interestingly, many patients with MD consume large quantities of alcohol (8), frequently exceeding the amount necessary to relieve the myoclonus, or even to be addicted to alcohol or drugs (11). Some patients, including several members of the family under study, also display features of psychiatric disorders͞affective traits such as anxiety, neurosis, phobias (11), depression, and panic attacks (M.F.B.…”