Hypokalaemic Hypertension and 17-Alpha-hydroxylase/17,20-lyase Deficiency in a Young Girl: a Case Report

Case presentationA young girl aged 9 years 6 months was admitted to hospital in July 2022 with coronavirus disease 2019 infection and found to have refractory hypokalaemia.She reported good past health and denied taking any supplements or medications.Her nonconsanguineous parents and 4-year-old younger brother were healthy and family history was unremarkable.Her body weight and height were 35.8 kg at the 75th to 95th percentile and 140 cm at the 75th percentile, respectively.Her body mass index was 18.3 kg/m 2 at the 75th percentile.Blood pressure was noted to be persistently high up to 152/117 mm Hg (112/73 mm Hg being the 90th percentile for her gender, age and height according to the American Academy of Pediatrics 1 ).Cardiovascular and abdominal examinations were unremarkable.There was no hyperpigmentation or sign of virilisation.She was prepubertal, with normal female external genitalia.Ambulatory blood pressure monitoring confirmed stage 2 hypertension.Electrolytes and hormone profile are summarised in the Table .Her bone age was 8 years 10 months according to the Greulich and Pyle method of assessment.A standard-dose Synacthen test did not stimulate a rise in 17-hydroxyprogesterone or cortisol level.Ultrasound of the pelvis revealed prepubertal uterus and bilateral ovaries.Her karyotype was 46,XX.Urine steroid profile showed a characteristic pattern compatible with 17-alphahydroxylase/17,20-lyase deficiency (17OHD), with a lack of androgen metabolites and an excess of progesterone, pregnenolone, and corticosterone metabolites (online supplementary Appendix).Oral hydrocortisone was commenced at 7.6 mg/m 2 /day.Blood pressure improved to 119/81 mm Hg after 2 weeks.Spironolactone was added for better control.Genetic analysis revealed compound