A NEW TYPE OF INHERITED GROWTH HORMONE DEFICIENCY: A COMPOUND HETEROZYGOTE OF A 6.7 KB DELETION, INCLUDING THE GH-1 GENE, AND TWO BASE DELETION IN THE THIRD EXON OF THE GH-1 GENE

Abstract

The genomic DNA in a patient with severe growth retardation was analysed and a new type of mutation, a compound heterozygous mutaion, was found in her GH-1 gene. The patient was a 13 years old girl, a first child of unrelated parents and born by normal delivery. She had been diagnosed as growth hormone deficiency at the age of 8 years 11 months. Her height and weight were 86.1 cm (−7.8SD) and 10.2 kg (−3.4SD), respectively. She has been treated with exogenous hGH successfully over years without producing antibody against hGH by now. The genomic DNA of this patient and her parents were analyzed by polymerase chain reaction followed by restriction enzyme digestion as reported by Vneneak-jones et al. and the existence of 6.7 kb deletion including whole GH-1 gene was found in one allele of the patient and her father but not in her mother. The sequence analysis of this family revealed the 2 bp deletion in exon 3 of GH-1 gene in the patient and her mother but not in her father. A termination codon at the position of amino acid residue 132 in exon 4 was assumed to be introduced through this mutation. These results might suggest the new type of inherited GH-1 gene deficiency caused by heterozygous mutation in GH-1 gene.