A family with isolated growth hormone deficiency (IGHD) in two children and their mother is reported. Genetic analysis revealed a heterozygous splice site mutation in intron III of the GH-1 gene. This mutation was de novo in the mother and was transmitted in a dominant way to her offspring.
Conclusion: De novo mutations in the GH-1 gene may be an important cause of congenital idiopathic IGHD. As these patients have normal fertility, pointing out this mutation is of great value for appropriate genetic counselling in patients with idiopathic IGHD.