Family data in Rett syndrome: association with other genetic disorders

BACKGROUND: Rett syndrome is a neurological disorder, almost exclusively affecting girls. METHODOLOGY: Between 1993 and 1995 pedigree data were obtained from families of girls registered with the Australian Rett syndrome database. RESULTS: Although 21 individual disorders were reported to be present in family members of affected girls, there was no apparent clustering of the same disorder in different families. However it was certain that a geneticist had been involved in only 10.9% of cases. CONCLUSIONS: Mutations in the MECP2 gene have now been reported in a proportion of sporadic cases. Thus, it will be important to examine this phenotype-genotype correlation in the Australian cohort. Where a mutation is found, prenatal diagnosis in a subsequent pregnancy will be a possibility. Using the Australian population database and in conjunction with the clinical genetic services in each state it is planned to contact families with an affected girl to offer testing and counselling.     

How strong is the association between abdominal obesity and the incidence of type 2 diabetes?

Background: Quantitative evidence on the strength of the association between abdominal obesity and the incidence of type 2 diabetes was assessed. Methods: Systematic review of longitudinal studies assessing the relationship between measures reflecting abdominal obesity and the incidence of type 2 diabetes. Results: There was a strong association between measures reflecting abdominal obesity and the incidence of type 2 diabetes, the pooled odds ratio was 2.14 (95% CI: 1.70–2.71; p < 0.0001). Waist circumference (WC) was at least as good as other measures in predicting outcome. Conclusions: There is a strong association between measures reflecting abdominal obesity and the development of type 2 diabetes. Reducing WC may reduce the risk of developing type 2 diabetes.     

Symptoms and longitudinal changes in lung function in young seasonal grain handlers

A total of 119 seasonal grain handlers (mean age 23) were assessed before and towards the end (mean work period 18 days) of the 1983 Western Australian grain harvest to determine if respiratory symptoms that occur with exposure to grain dust are associated with changes in ventilatory capacity or non-specific bronchial reactivity to methacholine. Eighteen per cent of subjects had wheeze, breathlessness, or chest tightness and 18% had cough or sputum production at work. Subjects complaining of wheeze, chest tightness, or breathlessness at work had a significantly greater decline in FEV1 than subjects who did not experience these symptoms (p less than 0.05). Symptoms were not associated with changes in bronchial reactivity. In young grain handlers who develop respiratory symptoms on short term exposure to grain dust changes in FEV1 but not in non-specific bronchial reactivity have been demonstrated.