Isolated Growth Hormone Deficiency Type 1A without Apparent Growth Hormone 1 Gene Deletion

We document a Japanese girl who, without apparent growth hormone (GH)-l gene deletion, had a clinical phenotype identical to that of isolated growth hormone deficiency type 1A (IGHD-1A). The restriction fragment length polymorphism (RFLP) linkage analysis of the patient and her family members indicates that her GH-1 gene is structurally intact, though the molecular basis of her GH deficiency remains to be determined. We suspect that several congenital disorders other than GH-1 gene mutations may be responsible for IGHD-1A phenotype.