Huntington's Disease Genetic Heterogeneity In African Patients

SUMMARY Huntington’s disease 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 tri-nucleotide repeat at the chromosome 4 HD locus was previously regarded as a way of excluding classical Huntington’s disease (HD). The objective of this paper is to describe a number of black patients with genetically proven Huntington’s disease and review its occurrence in Africa. Methods: Eleven black families (twelve subjects), with genetically proven Huntington’s disease are described, nine from the Dr George Mukhari Hospital and two from private practice in Tshwane. Results: Chorea was present in all 12 patients and cognitive decline in nine. Nine had an age of onset between 30-50 years. Six families exhibited expansion of the trinucleotide repeat at the chromosome 4, IT 15 gene (HD) and five 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 or HDL2) appears to be similar. The actual rate of occurrence of Huntington’s disease in Blacks may require reassessment. With the number of Huntington’s chorea patients occurring in our area (Garankuwa), the possibility of clustering of the condition arises

Global and regional effects of potentially modifiable risk factors associated with acute stroke in 32 countries (INTERSTROKE): a case-control study

Background: Stroke is a leading cause of death and disability, especially in low-income and middle-income countries. We sought to quantify the importance of potentially modifiable risk factors for stroke in different regions of the world, and in key populations and primary pathological subtypes of stroke. Methods: We completed a standardised international case-control study in 32 countries in Asia, America, Europe, Australia, the Middle East, and Africa. Cases were patients with acute first stroke (within 5 days of symptom onset and 72 h of hospital admission). Controls were hospital-based or community-based individuals with no history of stroke, and were matched with cases, recruited in a 1:1 ratio, for age and sex. All participants completed a clinical assessment and were requested to provide blood and urine samples. Odds ratios (OR) and their population attributable risks (PARs) were calculated, with 99% confidence intervals. Findings: Between Jan 11, 2007, and Aug 8, 2015, 26 919 participants were recruited from 32 countries (13 447 cases [10 388 with ischaemic stroke and 3059 intracerebral haemorrhage] and 13 472 controls). Previous history of hypertension or blood pressure of 140/90 mm Hg or higher (OR 2·98, 99% CI 2·72–3·28; PAR 47·9%, 99% CI 45·1–50·6), regular physical activity (0·60, 0·52–0·70; 35·8%, 27·7–44·7), apolipoprotein (Apo)B/ApoA1 ratio (1·84, 1·65–2·06 for highest vs lowest tertile; 26·8%, 22·2–31·9 for top two tertiles vs lowest tertile), diet (0·60, 0·53–0·67 for highest vs lowest tertile of modified Alternative Healthy Eating Index [mAHEI]; 23·2%, 18·2–28·9 for lowest two tertiles vs highest tertile of mAHEI), waist-to-hip ratio (1·44, 1·27–1·64 for highest vs lowest tertile; 18·6%, 13·3–25·3 for top two tertiles vs lowest), psychosocial factors (2·20, 1·78–2·72; 17·4%, 13·1–22·6), current smoking (1·67, 1·49–1·87; 12·4%, 10·2–14·9), cardiac causes (3·17, 2·68–3·75; 9·1%, 8·0–10·2), alcohol consumption (2·09, 1·64–2·67 for high or heavy episodic intake vs never or former drinker; 5·8%, 3·4–9·7 for current alcohol drinker vs never or former drinker), and diabetes mellitus (1·16, 1·05–1·30; 3·9%, 1·9–7·6) were associated with all stroke. Collectively, these risk factors accounted for 90·7% of the PAR for all stroke worldwide (91·5% for ischaemic stroke, 87·1% for intracerebral haemorrhage), and were consistent across regions (ranging from 82·7% in Africa to 97·4% in southeast Asia), sex (90·6% in men and in women), and age groups (92·2% in patients aged ≤55 years, 90·0% in patients aged 55 years). We observed regional variations in the importance of individual risk factors, which were related to variations in the magnitude of ORs (rather than direction, which we observed for diet) and differences in prevalence of risk factors among regions. Hypertension was more associated with intracerebral haemorrhage than with ischaemic stroke, whereas current smoking, diabetes, apolipoproteins, and cardiac causes were more associated with ischaemic stroke (p<0·0001)

Practice patterns and outcomes after stroke across countries at different economic levels (INTERSTROKE):an international observational study

Background: Stroke disproportionately affects people in low-income and middle-income countries. Although improvements in stroke care and outcomes have been reported in high-income countries, little is known about practice and outcomes in low and middle-income countries. We aimed to compare patterns of care available and their association with patient outcomes across countries at different economic levels. Methods: We studied the patterns and effect of practice variations (ie, treatments used and access to services) among participants in the INTERSTROKE study, an international observational study that enrolled 13 447 stroke patients from 142 clinical sites in 32 countries between Jan 11, 2007, and Aug 8, 2015. We supplemented patient data with a questionnaire about health-care and stroke service facilities at all participating hospitals. Using univariate and multivariate regression analyses to account for patient casemix and service clustering, we estimated the association between services available, treatments given, and patient outcomes (death or dependency) at 1 month. Findings: We obtained full information for 12 342 (92%) of 13 447 INTERSTROKE patients, from 108 hospitals in 28 countries; 2576 from 38 hospitals in ten high-income countries and 9766 from 70 hospitals in 18 low and middle-income countries. Patients in low-income and middle-income countries more often had severe strokes, intracerebral haemorrhage, poorer access to services, and used fewer investigations and treatments (p<0·0001) than those in high-income countries, although only differences in patient characteristics explained the poorer clinical outcomes in low and middle-income countries. However across all countries, irrespective of economic level, access to a stroke unit was associated with improved use of investigations and treatments, access to other rehabilitation services, and improved survival without severe dependency (odds ratio [OR] 1·29; 95% CI 1·14–1·44; all p<0·0001), which was independent of patient casemix characteristics and other measures of care. Use of acute antiplatelet treatment was associated with improved survival (1·39; 1·12–1·72) irrespective of other patient and service characteristics. Interpretation: Evidence-based treatments, diagnostics, and stroke units were less commonly available or used in low and middle-income countries. Access to stroke units and appropriate use of antiplatelet treatment were associated with improved recovery. Improved care and facilities in low-income and middle-income countries are essential to improve outcomes