Pilot study of measurement of respiratory chain complexes in Hong Kong

Abstract

According to the previous studies in Caucasian populations, the prevalence of mitochondrial disease (MD) is at least 1 in 5000, implying that this inborn error metabolism disease is not as rare as we originally thought. As the awareness of local clinicians toward MD increases, the underestimation of MD should be improved and there will be higher demand for the accurate diagnosis. The accurate diagnosis of MD needs to integrate the biochemical, histochemical and molecular approaches. In which, the biochemical measurement of activities of different respiratory chain (RC) complexes in the muscle biopsies is regarded as the gold standard of diagnosis for paediatric MD patients. However, this measurement is not available in Hong Kong or China. Patients have to send their muscle biopsies to overseas centres for the diagnosis. This does not only increase their financial burden, but also lengthens the diagnosis time. As a result, the measurement of RC complex I, II and citrate synthase has been set up in this pilot study. Our results of 5 normal controls and 5 positive controls were comparable to one of the world renowned centres of mitochondrial research, the Nijmegen Centre for Mitochondrial Disorders in Netherland. In addition, we have established our own internal quality control for monitoring the precision of the assays. Our next step is to complete the profile of RC complexes measurement to set a milestone of MD diagnosis in Hong Kong.