Aim We aim to raise awareness among Paediatricians to a group of conditions that are individually rare but collectively appear not to be so. Three cases were diagnosed in a medium sized district hospital, two of which were identified within 6 months.

Hypoglycemia in an iugr baby A phenotypically normal female baby born to consanguineous Asian parents, presented with mild but persistent hypoglycemia. She had undetectable plasma cortisol and no response to Synacthen stimulation. Congenital adrenal hyperplasia or hypoplasia were considered. However her urine steroid profile showed absent glucocorticoid and androgens metabolites despite normal to high plasma aldosterone and ACTH level over 1000. A clinical diagnosis of ACTH unresponsiveness was made, and subsequently confirmed by detecting a novel homozygous mutation in FGD2 gene. She was treated with steroid replacement therapy.

Abnormal thyroid function tests (tft) in a healthy term baby A Caucasian baby had her TFT checked incidentally. Her fT3 & T4 levels were persistently elevated but TSH remained unsuppressed. She was asymptomatic, though it was felt she had mild transient tachycardia and slightly increased feeding pattern. TFT screening of the family revealed that her father, who is asymptomatic, has a similar pattern. Resistance to Thyroid Hormone was confirmed with TRb gene mutation. No treatment was needed.

Weight loss, hyponatremia and hyperkalemia A 2 weeks old boy born to unrelated Asian parents presented with 10% weight loss and mild dehydration despite adequate feeding. He had normal renal functions, adequate plasma cortisol and unremarkable urine steroid profile. He had strikingly high plasma renin and Aldosterone with no sodium loss on sweat testing. His mother used to crave salt. Clinical diagnosis of AD Pseudohypoaldosteronism type I was made awaiting genetic confirmation. He remained well on sodium supplements with persistently elevated aldosterone.

Conclusion In the future, it is expected that additional hormone resistance syndromes will be diagnosed and described. Lack of clinical or biochemical effect of elevated hormone level that results in a lack of feedback inhibition should raise suspicion of hormone resistance. Relevant biochemical screening of family is timely effective in aiding diagnosis while awaiting genetic confirmation.