UGT1A1 haplotype mutation among Asians in Singapore

BACKGROUND

The uridine diphosphate glucuronosyltransferase 1A1 (UGT1A1) enzyme is responsible for conjugation of the bilirubin in the liver as well as for drug metabolism. Some of the polymorphisms have been associated with an increased risk of neonatal hyperbilirubinemia which may explain the increased incidence of jaundice in an Asian population as well as exaggerated irinotecan-induced leukopenia.

OBJECTIVE

The local Asian incidence of hypomorphic haplotypes, defined as gene mutations known to have a reduced function, has not been described. Clinical correlation between the mutations and the need for phototherapy for hyperbilirubinemia was carried out.

METHODS

A cohort of 241 consecutive term infants delivered in the National University Hospital, Singapore, was recruited with parental consent. Cord blood was collected, and the promoter and coding regions of the UGT1A1 gene were sequenced.

RESULTS

Six known haplotypes and 2 novel haplotypes were identified: 1 wild type, 5 with reduced function, while the 2 novel ones were predicted to have decreased function. The frequency of these hypomorphic haplotypes was high. Among the 241 infants screened, 35% had 1 hypomorphic haplotype and 12% had 2 hypomorphic haplotypes. The frequency was also different among ethnic groups, with 48% Chinese, 64% Indian and 31% Malay infants having at least 1 hypomorphic haplotype (chi(2) test, p < 0.05). There was a trend seen between the number of G71R mutations and the need for phototherapy (chi2 test for trend, p < 0.05).

CONCLUSIONS

The local Asian incidence of hypomorphic haplotypes was high and there was a trend between the number of G71R mutations and the need for phototherapy. The G71R mutation may account for the increased incidence of neonatal jaundice seen in Asian populations.

Immunosuppressive therapy in acute myocarditis: an 18 year systematic review

BACKGROUND

Immunosuppressive therapy is reportedly ineffective in adults with acute myocarditis.

AIMS

To systematically review the impact of immunosuppressive therapy on the outcome of acute myocarditis in children.

METHODS

A literature search for articles published from 1984 to 2003 was conducted with the following keywords: myocarditis, dilated cardiomyopathy, and immunosuppression. The relevant studies were systematically reviewed and comparison of treatment effect was made by calculating the odds ratio (OR) and confidence interval (CI) using the exact method based on the exact discrete reference distribution.

RESULTS

Of the 1470 articles found, only nine studies were eligible. The odds for improvement with immunosuppression was between 4.33 (95% CI 0.52 to 52.23) and 2.7 (95% CI 0.59 to 14.21). Addition of a second immunosuppressive agent to prednisolone only proved effective in one randomised controlled trial (OR 0.09, 95% CI 0.01 to 0.52). Heterogeneity of these studies precluded pooled odds ratio.

CONCLUSION

Current data suggest that immunosuppressive therapy does not significantly improve outcomes in children with acute myocarditis and there is insufficient evidence for its routine use. However, statistical power to detect a significant difference in the treatment effect may be limited because of the small number of subjects. This, together with problems of diagnosis, varying treatment practices, and a relative lack of evidence based guidelines would support efforts for a large multicentre, randomised controlled trial to better define the role of immunosuppression in acute myocarditis.

The prevalence of asthma and allergies in Singapore; data from two ISAAC surveys seven years apart

BACKGROUND AND AIMS

Over the past few decades, the prevalence of asthma has been increasing in the industrialised world. Despite the suggestion of a similar increase in Singapore, the 12 month prevalence of wheeze among schoolchildren in 1994 was 2.5-fold less than that reported in western populations. It was hypothesised that with increasing affluence in Singapore, the asthma prevalence would further increase and approach Western figures. A second ISAAC survey was carried out seven years later to evaluate this hypothesis.

METHODS

The cross-sectional data from two ISAAC questionnaire based surveys conducted in 1994 (n = 6238) and in 2001 (n = 9363) on two groups of schoolchildren aged 6-7 and 12-15 years were compared. The instruments used were identical and the procedures standardised in both surveys.

RESULTS

Comparing data from both studies, the change in the prevalence of current wheeze occurred in opposing directions in both age groups--decreasing in the 6-7 year age group (16.6% to 10.2%) but increasing to a small extent in the 12-15 year age group (9.9% to 11.9%). The 12 month prevalence of rhinitis did not change; there was an increase in the current eczema symptoms in both age groups.

CONCLUSION

The prevalence of current wheeze, a surrogate measure of asthma prevalence, has decreased significantly in the 6-7 year age group. Eczema was the only allergic disease that showed a modest increase in prevalence in both age groups.