Detection of the cystic fibrosis delta-F508 mutation at autopsy by site-directed mutagenesis.

In Causasian populations cystic fibrosis (CF) is the most common autosomal recessive disorder. CF was previously considered rare in Mexico; however, the reported frequency is about 1% in autopsies. This discrepancy appears to be due to the inability to diagnose the illness during life. It is now known that in developing countries a great number of affected children die without the benefit of CF diagnosis and appropriate treatment. In this study we have used the PCR-mediated site-directed mutagenesis technique for the detection of the delta-F508 mutation in a 6-month-old Mexican boy who died without definitive diagnosis. The tissue available from the child was a formaldehyde fixed paraffin-embedded liver. We identified the delta-F508 mutation in homozygous form in the propositus and in a heterozygous form in his parents. This represents the first report of CF molecular diagnosis in Mexico.