CONGENITAL ADRENAL HYPERPLASIA DUE TO 3 beta-HYDROXYSTEROID DEHYDROGENASE (3bHSD) DEFICIENCY.An eight weeks old boy, first child to nonconsanguineous parents of Swedish extraction, presented with severe dehydration and salt loss. Plasma Na 109 and plasma K 8.7mval/l. He had a phallus 1,5 cm in length, meatus in the peniscrotal junction and a bifid scrotum with gonads on both sides. Normal blood pressure. After rehydration and hydrocortison i.v. the boy was substituted with 10 mg hydrocortison and 0.05 mg fludrocortison daily. Steroids in 24 hours collection of urine were analysed by capillary gas chromatography mass spectrometry. More than 90% of the steroids were 3beta-5-en steroids mainly androst-5-en-3,17,20-triol, 16 alphahydroxy-DHA and pregn-5-en3,17,20-triol. Plasma levels of 17-OH-P, DHA, androstendion and aldosteron were analysed by RIA. During the salt crisis aldosteron was 1650 pmol/L and decreased to 775 during substitution. During ACTH stimulation 17 OH-P and androstendion were 7 and 2,4 nmol/~ respectively which is lower than usually seen in 21 hydroxylasedeficient children in poor control. We find the case consistent with 3bHSD deficiency of partial but stillsalt loosing type. as already observed in a previous study (Gupta et a1,1983) .2.Night peak MEL values m e in the prepubertal range irrespective of the age and dwelopcental stage of the subject. 3.Desynchmnized ultradian rhythms were present in all subjects except one,a 17-yrs. old XO/XX girl who had spntaneous mstruations. 4.m relationship between MEL serum levels and gonadotrophin concentrations were found. 5.In sow of the patients the night elevation in serum PRL levels m s very pronounced. These data illustrate the principle that c m s o m a l abmnnality may be antecedent to the developcent of aberrations in relation to the pineal biorhythm.Wever,this is simply a hypothesis which should be examined further. The effect of L-DOPA on basal LH, FSH and Prolactin (Pr) secretion in subjects with Turner syndrome. The dopaminergic tuberoinfundibular system has been shown to play a role in the regulation of the pituitary secretion of LH an Pr in experimental animals. In humans,DA and DA agonists have an inhibitory effect on LH and Pr release which differs in the two sexes and in women in the different phases of the menstrual cycle. We examined the effect of L-DOPA in the dose used for GH stimulation on the LH,FSH and Pr levels in 9 subjects with Turner syndrome, who had never received estrogens.We found the following (mean 5 SD) . DUNGER DB*,LIGHTMAN S*,WILLIAMS M*, GRANT DB,PREECE M -The Hospitals for Sick 128 Children, The Westminster Hospital, London Hvpodipsia. osmoreceptor dysfunction, early puberty and abnormal behaviour in two boys Two unrelated boys (A l3yrs B 18yrs) presenting with early puberty and episodes of aggressive behaviour were found to have hypernatraemia(Na 147-160 mmol/l, osmolality 298-323mosmol/kg) and hypodipsia. Plasma vasopressin(AVP) levels were in the range seen in diabetes insipidus(<2pmol/l), yet 24hr urinary volumes ...