[Indirect genetic diagnosis of cystic fibrosis]

The diagnosis cystic fibrosis was made in a three years old girl. Her older brother and her mother's sister both had minor symptoms and signs suggestive of this disease. None of 17 mutations in the gene locus for cystic fibrosis was identified in the patient by DNA-analyses. By haplotype analyses her brother, but not her aunt, was shown to share the proband's haplotypes. This family is used as an example of the general diagnostic potential of indirect diagnosis of genetic disease by haplotype analysis. The prerequisite for haplotype analysis is the availability of DNA from both the patient and the patient's relatives, stressing the need for a DNA bank of material from persons with inherited disorders, for future use.