Ascertainment of Indonesian families with schizophrenia for affected sib-pair analysis

There are 31 mental state hospitals in Indonesia serving a population of 217 million. Having a large number of patients, these hospitals offer an ideal source for recruitment of families for genetic studies in schizophrenia. Beside the common difficulties in ascertainment such as low compliance, we experience specific problems like incomplete medical records, multiple language dialects, high missing rate of patients, and biased information because of stigma and unawareness of genetic problems. Another difficulty is the location of these hospitals, which are scattered all over Indonesia (about 1,919,440 square km). We have recruited more than 80 families with schizophrenia for affected sib-pair linkage analysis from 10 mental state hospitals in Java and Bali. Recruiting is currently being extended to other hospitals in major islands of Indonesia. About 70% of the families have both parents available. In 30%, one parent is missing, but additional unaffected siblings allow reconstruction of the missing genotype. Thus, genetic analysis can be done strictly as identity by descent. For clinical assignment we use all relevant data and Diagnostic Interview for Psychoses (DIP), a semi-structured interview for patients. Other instruments include Personal Psychiatric History Schedule (PPHS) and Family Interview for Genetics Studies (FIGS). We also use OPCRIT computer algorithm program to make diagnosis according to DSMIII-R and ICD-10. Genotyping and genetic analysis of markers in candidate region of chromosome 4q, 5q, 6p, 6q, 8p, 10p, 13q are currently being done in collaboration with the Bonn group.