ABSTRACT
BACKGROUND: Type Ib pseudohypoaldosteronism is a congenital disorder characterized in the newborn by salt loss caused by multiple end-organ resistance to aldosterone. An autosomal recessive mode of inheritance has been reported. Its particularity is the spontaneous improvement by 18 months to 2 years, due to an improved tubular response of the kidneys to mineralocorticoids, or earlier when given salt supplements once the diagnosis is made. OBSERVATIONS: We observed three children with this disease, which was revealed by day 8 to day 15 of life; one of these presented respiratory symptoms identical to those of cystic fibrosis, and another one an apparently chance association with a rod myopathy. CONCLUSION: Recent findings in the literature demonstrate the molecular aspects of pseudohypoaldosteronism and lead to an interesting comparison with cystic fibrosis by explaining their similar physiopathology through the activity of epithelial sodium channels.