Apparent mineralocorticoid excess due to 11 beta-hydroxysteroid dehydrogenase deficiency: a possible cause of intrauterine growth retardation.

A Japanese boy with apparent mineralocorticoid excess (AME) is described. He was born with intrauterine growth retardation (IUGR) and elevated serum level of creatine phosphokinase (CPK). He was studied at 2 years of age because of polyurea and polydipsia of one year's duration and was found to have hypokalaemic alkalosis and sustained hypertension. His plasma renin activity and aldosterone levels were always low and his ratio of urinary tetrahydrocortisol plus allo-tetrahydrocortisol to that of tetrahydrocortisone was very high. Therefore, AME due to 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) deficiency was diagnosed. He was successfully treated with a combination of spironolactone and nifedipine for at least 16 months. His blood pressure, plasma pH and serum potassium levels were normalized by this treatment, but serum CPK level remained high. We researched the birth records of previously reported AME cases and found that IUGR is a characteristic feature of AME. The mechanism by which IUGR occurs in AME is discussed and we speculate that 11 beta-HSD might be deficient in the placenta and/or fetal tissues, as well as in the kidney, in AME. An explanation for the elevated CPK could not be found.