Pitfalls in the use of chromosome variants for paternity dispute cases.

A huge 'satellite' (22s+) was observed in a mentally retarded and malformed girl. It consisted of constitutive heterochromatin based on the C-band technique (CBG). In neither of the parents was the variant observed. Genetic marker studies revealed that the father was, indeed, the father of the proposita (probability, 99.8%). It is emphasized that caution must be taken in the use of chromosome variants for paternity dispute cases.