We report the sporadic case of a 9 year-old boy with Carney syndrome, who presented with precocious puberty due to the endocrinological effects of primary pigmented nodular adrenocortical disease (PPNAD) and a synchronous pituitary adenoma. The adrenal tumor was removed surgically. Following unsuccessful treatment with bromocriptine the pituitary adenoma was also resected and a residual tumor irradiated. Thirty months after diagnosis the boy is free of symptoms. Mutation screening of the entire coding region of the PRKAR1A gene identified five single nucleotide exchanges, four of which were either heterozygous or homozygous polymorphic variants that were also present in his parents. However, the hitherto unreported disease-relevant mutation R96X in exon 3 had occurred de novo on the paternal allele.