Studies of GH gene defects in familial Isolated Growth Hormone Deficiency (IGHD).

ABSTRACT

One family with isolated GH deficiency (IGHD) was Studied. To determine GHI gene deletions, PCR and Southern blot analyses were used. None of the possible deletions were found in the subjects but the GH1 gene mutation was found. The family consisted of parents (both 140 cm) and their three children with isolated GHD. The daughter and two sons were first seen between 2.9 and 5.3 years of age when their HtSDSs were -2.2 to -3.6, and peak GHs were 0.9 to 4.0 mg/ml. The GH1 gene change was found in G-->A substitution at +28 in the intervening sequence or intron 3 (IVS3+28 G-->A). This change is a dominant-negative mutation which has never occurred in any reports in any reports in Thailand and we were the first group to report here. The segregation which and expression studies of the IVS3+28 G-->A variant are underway to confirm whether it is a new dominant-negative mutation that causes GHD by perturbing mRNA splicing.