LONG-TERM FOLLOW-UP OF A 46,XY PHENOTYPIC GIRL WITH 17-ALPHA-HYDROXYLASE DEFICIENCY TREATED WITH ALTERNATE-DAY DEXAMETHASONE

We report an 18-year-old 46,XY phenotypic girl who has been on alterna te-day dexamethasone therapy for 10 years. The patient was seen at our hospital for right-sided inguinal hernia at the age of 4 years. Biops y of the herniated gonad showed testicular tissue, and the karyotype o f the peripheral lymphocytes was 46,XY. The diagnosis of 17 alpha-hydr oxylase deficiency was established by the evaluation of adrenal steroi dogenesis at the age of 6.1 years when hypertension was clearly recogn ized, and was confirmed later by the gene analysis of CYP17 which disc losed a compound heterozygote. The growth rate was suppressed during t he initial treatment with daily administration of 0.25-0.5 mg dexameth asone. Switching to alternate-day regimen of dexamethasone 0.5 mg/dose improved height velocity. Subsequent addition of low-dose estrogen th erapy induced pubertal growth spurt. The blood pressure and adrenal ho rmone levels remained almost within the normal range throughout the co urse. Adrenal function was evaluated at the age of 15 years. Plasma AC TH and corticosterone levels were high only just before the next admin istration, when the plasma dexamethasone concentration should be at th e nadir. Since corticosterone possesses glucocorticoid activity and ca n work as a glucocorticoid reserve, it is assumed that this mode of de xamethasone administration can be a safe treatment for this disorder. We conclude that the patient with childhood 17 alpha-hydroxylase defic iency can be safely and effectively treated with alternate-day dexamet hasone without interfering with linear growth.