Mihoko Kodama

THE GROWTH HORMONE RECEPTOR GENE MUTATION OF A JAPANESE PATIENT WITH LARON SYNDROME

SummaryDeletions and point mutations of the growth hormone (GH) receptor gene (GHR) have been identified in patients with Laron syndrome. We report the first detection of the GHR mutation among Japanese patients with Laron syndrome. Using the Japanese female patient’s genomic DNA as a template, all exons and flanking portions of introns of GHR were amplified by polymerase chain reaction (PCR). Sequencing of the PCR products showed that the patient was homozygous for a G to A substitution at the first position of intron 4. This substitution was same as that detected in a Spanish patient and a north European patient. The base change occurred at the 5′ splice consensus sequence of intron 4, resulting in the abolition of a BanI restriction site. Since this substitution was not detected by a BanI restriction analysis in 85 control individuals, it is more likely a disease-related splice mutation than a polymorphism. The mutation in our patient was predicted to destroy the original 5′ splice site of intron 4 of GHR and to produce a new cryptic splice site, leading to abnormal mRNA processing and a lack of GH binding activity of GH-binding protein (GHBP).

Glucoregulatory disorders in school-refusal students

Our previous studies demonstrated autonomic nervous system disorders and cerebral blood hypoperfusion in school refusal students with underlying emotional distress due to fear or anxiety associated with school attendance. Because severe stress is known to affect glucoregulatory metabolism, this study used the oral glucose tolerance test (OGTT) to measure glucose metabolism in school refusal students.

Aarskog syndrome with isolated growth hormone deficiency

A 5-year-old male with the Aarskog syndrome is described. He had abnormal facies, short stature, short fingers with interdigital webbing, a saddle type scrotum and mild mental retardation. In addition, he had isolated growth hormone deficiency as evidence by the insulin, arginine, and propranolol-glucagon tests. An arginine test after short-term stimulation with estrogen further supported this diagnosis. His mother had minor abnormalities of the hands and feet, and slight mental retardation.