RESUMEN
OBJECTIVE: Huntington's disease (HD) has been reported to occur rarely in black patients. A new genetic variant- Huntington's disease-like 2 (HDL2)--occurring more frequently in blacks, has recently been described. The absence of an expanded trinucleotide repeat at the chromosome 4 HD locus was previously regarded as a way of excluding classic HD. The objective of this paper is to describe a number of black patients with genetically proven HD and to review its occurrence in Africa. METHODS: Eleven black families (12 subjects), with genetically proven HD, are described: 9 from the Dr George Mukhari Hospital, and 2 from private practice in Tshwane. RESULTS: Chorea was present in all 12 patients and cognitive decline in 9. Nine had an age of onset between 30 and 50 years. Six families exhibited expansion of the trinucleotide repeat at the chromosome 4, IT 15 gene (HD), and 5 a junctophilin (JPH3) trinucleotide expansion at chromosome 16 (HDL2). The HDL2 subtype showed a tendency towards a later age of onset. CONCLUSIONS: The clinical presentation of the two genotypes (i.e. HD and HDL2) appears to be similar. The actual rate of occurrence of HD in blacks may require re-assessment. Considering the number of Huntington's chorea patients occurring in our area (Garankuwa), the possibility of clustering of the condition arises.
Asunto(s)
Población Negra/genética , Heterogeneidad Genética , Enfermedad de Huntington/genética , Adulto , Edad de Inicio , Cromosomas Humanos Par 4 , Femenino , Genotipo , Humanos , Proteína Huntingtina , Enfermedad de Huntington/epidemiología , Masculino , Proteínas de la Membrana/genética , Persona de Mediana Edad , Proteínas del Tejido Nervioso/genética , Proteínas Nucleares/genética , Sudáfrica/epidemiología , Sudáfrica/etnología , Expansión de Repetición de TrinucleótidoRESUMEN
BACKGROUND: The increase in HIV infections in South Africa is alarming. The aim of this prospective 4-year study was to evaluate the rising incidence of HIV-related admissions due to meningitis at the Pretoria Academic Hospital (PAH) adult neurology ward and to investigate the spectrum of meningitis during this time. PATIENTS AND METHODS: Adults with meningitis presenting at the PAH neurology ward from March 1994 through February 1998 were included. HIV antibody status was determined and patients were assigned to five categories: bacterial, tuberculous, viral and cryptococcal meningitis, as well as an uncertain category. RESULTS: Over the 4-year study period 141 patients with meningitis were seen. Of these, 44 were HIV-positive (31%), with TB meningitis occurring in 16 (36%), cryptococcal meningitis in 22 (50%) and acute bacterial meningitis in three (7%). In the first 2 years of the study, 14% of patients were HIV positive; this figure rose to 44% in the 3rd year, and 57% in the final year. The spectrum of meningitis also changed: bacterial meningitis remained relatively stable at about 25% of the total; TB meningitis almost doubled from 16% in the 1st year to 31% in the last year of the study; viral meningitis initially occurred in 8% of patients and later in 3% of cases, while cryptococcal meningitis showed the most significant increase from 6% of cases in 1994/5 to 31 and 26% respectively in the last 2 years of the study. CONCLUSION: Over a 4-year period the HIV epidemic was responsible for a marked shift in the spectrum of meningitis towards chronic infections such as TB and cryptococcal meningitis at the PAH.