REN and Leigh syndrome: Particularly, since approximately 7–8% of patients diagnosed with LS are normotensive [205], and considering the incomplete penetrance of the disease, it is important to screen for this condition in individuals presenting with refractory hypertension or isolated hypokalaemia, particularly when suppressed aldosterone and renin levels are associated with a strong family history of severe or refractory hypertension and/or hypokalaemia [215].