Molecular analysis of the growth hormone gene (GH1)in isolated growth hormone deficiency

A fraction of patients affected by the most severe form of isolated growth hormone deficiency (IGHD) carry mutations in the GH1 gene that abolish the production or alter the function of the mature peptide. We investigated the possible involvement of the GH1 gene in milder forms of the deficit in which a low but detectable amount of GH (< 8.0 ng/ml) is present after provocative stimuli. The GH1 gene and promoter were analyzed in 21 Italian and three Turkish sporadic patients and their parents. DHPLC analysis of the whole gene revealed two polymorphisms in intron 4 that are unlikely to affect the GH level. The GH1 promoter variations previously identified in the region between -75 and +25 showed comparable frequencies in patients and in a control panel, with the exception of -1T that showed a slightly increased frequency in patients with a borderline statistical significance.