Kifafa Seizure Disorder

Jilek-Aall et al. (1979) studied a seizure disorder called kifafa in an isolated tribe in the interior of Tanzania. About 200 cases were found among 10,000 persons. The disorder often led to severe burns in those afflicted. Many showed parkinsonian features and-or other neurologic abnormalities, as well as mental retardation and transient psychotic episodes. In children, head nodding was a frequent precursor of later grand mal seizures. Familial incidence was high; segregation analysis supported autosomal recessive inheritance. Jilek-Aall and Rwiza (1992) provided a 30-year follow-up. A prevalence of the disorder in the range of 19/1,000-36/1,000 with a mean age at onset of 11.6 years was found. Neuman et al. (1995) collected family data on 26 probands in 20 kifafa families. Of the 127 affected persons in these pedigrees, 23 were first-degree relatives of the 26 probands; 20 were second-degree relatives. When corrected for age, the risk to first degree relatives was 0.15; the risk to second degree relatives was 0.063. Among the mendelian single-locus models, an additive model was favored over either a dominant, recessive, or codominant model. The single-locus model could be rejected when compared with the mixed mendelian model (inclusion of a polygenic background), although the major-gene component tends to be recessive. However, the hypothesis of mendelian transmission could be rejected, suggesting that, although kifafa aggregates in these families, the mode of inheritance is genetically complex.