Huntington's disease-like 2 with an expansion mutation of the Junctophilin-3 gene; first reported case from Botswana.

Huntington's disease-like 2 (HDL2) is a rare autosomal dominant progressive neurodegenerative disorder commonly seen in adults. It was first described in a large African-American family in the United States. HDL2 clinically resembles Huntington's disease (HD) and causes adult-onset relentlessly progressive movement, emotional and cognitive dysfunction. Onset is usually in the fourth decade with slow progression to death. We present a 47-year-old male Botswana native, with a four-year-history of chorea, slurred speech, mood instability, cognitive impairment and weight loss. Genetic testing reveals normal HTT gene but a heterozygous expansion mutation at the JPH3 locus, confirmatory of HDL2. Though some cases of HDL2 have been reported from neighboring South Africa, this is the first instance from Botswana. This report draws attention to the fact that HDL2 exists among native Batswana, and even though clinically indistinguishable from HD, molecular testing can result in positive case identification.