Prenatal deletion detection in a sporadic case of Duchenne muscular dystrophy without genotype information from the affected individual.

We describe the application of deletion screening by amplification of deletion-prone exons via polymerase chain reaction (PCR) in a family with a sporadic case of Duchenne muscular dystrophy (DMD). No DNA was available from the affected patient who died 12 years beforehand at the age of 18 years. Material obtained prenatally from two male fetuses exhibited an identical deletion. These findings effectively transformed a sporadic case into a familial case and a numerical carrier risk was substituted by obligate carrier status. Additionally an indirect genotype analysis was replaced by the possibility of direct DNA analysis. Genetic counselling, formerly based upon incomplete data, can now be aided by precise risk assessment.