Thomsen syndrome (congenital myotonia syndrome; myotonia congenita)

General: Dominant; inheritance manifestations before age 5 years; prevalent in males; possibly caused by ex 343e42d cessive production of acetylcholine neuromuscular junction; emotions and cold enhance symptoms; warmth decreases symptoms; there are two types of this disorder, an autosomal dominant and an autosomal recessive, both with the same Clinical features; has been linked to chromosome 7q35 in the region of the human skeletal muscle chloride channel gene (HUMCLC).

Ocular: Inability to open eyelids for a few seconds after closure; spasm of the orbicularis oculi muscle; extraocular muscle paresis.

Clinical: Myotonia with muscles of upper and lower extremities primarily affected; muscle hypertrophy; pronounced delay in relaxation of contracted voluntary muscles.

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George AJ Jr, et al. Molecular basis of Thomsen's disease (autosomal dominant myotonia congenital. Nat Genet 1993; 3:305-310.

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Thomsen AJT. Myotonia Congenita: Tonische Krampfe in Willkurlich Beweglichen Muskeln in Folge von Ererbter Physischer Disposition (Ataxia Muscularis?). Arch Psych 1876; 6:702.