HADH and cartilage-hair hypoplasia: Flanagan et al (5) reported 11 cases with a median age of 7 weeks (1 day-26 weeks) at HH diagnosis and a median birth weight of 3.6 kg (2.8-4.35 kg) at 40 weeks gestation When Kapoor et al (6) studied the clinical and molecular characterisation of 300 patients with CHH, they identified three patients who had HADH mutations and were diazoxide-responsive.