A novel ABCA12 mutation 3270delT causes harlequin ichthyosis

Abstract

Conflicts of interest: None declared. Harlequin ichthyosis (HI) is a severe and often fatal congenital ichthyosis with an autosomal recessive inheritance pattern.1 The clinical features include thick, plate‐like scales with ectropion, eclabium, and flattened ears. The skin development is altered in utero.2,ABCA12 mutations have been reported to underlie HI3, 4 and it was clarified that HI is caused by severe functional defects in the keratinocyte lipid transporter ABCA12.3 The pathomechanism of HI lies in the defective function of the lipid transporter ABCA12 which causes abnormal lipid lamellar granule transport in the keratinocytes, and results in a malformation of the epidermal lipid barrier.3 Until the 1980s, newborns affected with HI rarely survived beyond the neonatal period. However, recently, HI babies have often had a better prognosis.5–7 It is still unclear whether the good prognosis in HI is due to some remnant ABCA12 protein transporter function in the patients or not. Here, we report a girl with HI with a novel homozygous ABCA12 deletion mutation leading to a complete loss of function of ABCA12, who has survived despite having severe ichthyosis showing the clinical features of nonbullous congenital ichthyosiform erythroderma (NBCIE).