Endocrine Abstracts

Type 1 pseudohypoaldosteronism (PHA1), defined as resistance to aldosterone, is characterised by salt wasting, hyperkalemia and metabolic acidosis and is associated with high renin and aldosterone levels. The autosomal recessive form is characterised by generalised salt wasting and is due to a defect in the epithelial sodium channel. Whilst there are individual case reports on this condition, there are little published data on long-term outcome including neurodevelopment.

Aims: We report a single centre experience of 8 cases of PHA1 managed over a 28 years period, including three pairs of siblings. The family history of consanguinity, age at presentation and clinical characteristics were consistent with the autosomal recessive form of PHA1.

Methods: A retrospective review of the available case notes of the children who attended a single tertiary paediatric endocrinology unit.

Results: All children presented within the first 2 weeks of life with lethargy and dehydration or circulatory collapse with electrolyte disturbance, sodium 116–133 mmol/l and potassium 7.9–11.2 mmol/l. Four patients, aged between 3 months to 24 years are currently alive; one of them with a neurodisability. Two of these patients displayed growth failure (weights <0.4th and 2nd–9th percentile, heights <0.4th percentile); the other 2 showed no growth problems (on or above the 50th percentile for weight and height). The current sodium requirements range between 2.8 and 8.5 mmol/kg per day for the >18-year-old and 21–25 mmol/kg per day for those aged <7 years. Four patients have died, two were index cases within the family, one a sibling of an index case. Two patients died in the first year of life; one with unexplained bowel perforation and one with intractable cardiac arrhythmia secondary to hyperkalemia. Another died at 4 years of age following a diarrhoeal illness, and a further patient at 20 years of age with hyperkalemia and cardiac arrest. Of the 4 non-survivors who died between ages 1 month to 20 years, two had significant mental and motor handicap.

Conclusions: PHA1 is a rare and challenging disorder, with a high morbidity and high mortality, even in diagnosed cases. Prompt diagnosis, regular review of electrolytes and education of the families to seek early medical attention are essential in management.