Harlequin ichthyosis: a review of clinical and molecular findings in 45 cases.

Objective: To assess the clinical outcomes of 45 cases of harlequin ichthyosis and review the underlying ABCA12 gene mutations in these patients.

Design: Multicenter, retrospective, questionnaire-based survey.

Setting: Dermatology research institute.

Participants: Patients with harlequin ichthyosis for whom we had performed ABCA12 mutation analysis.

Main Outcome Measures: Referring physicians were asked to complete a questionnaire using the patients' notes, detailing the clinical outcome of the affected child. In each case, the causative ABCA12 mutation was identified using standard polymerase chain reaction and sequencing techniques.

Results: Of the 45 cases, the ages of the survivors ranged from 10 months to 25 years, with an overall survival rate of 56%. Death usually occurred in the first 3 months and was attributed to sepsis and/or respiratory failure in 75% of cases. The early introduction of oral retinoids may improve survival, since 83% of those treated survived, whereas 76% who were not given retinoids died. Recurrent skin infections in infancy affected one-third of patients. Problems maintaining weight affected 44%. Three children developed an inflammatory arthritis, and developmental delay was reported in 32%. Mutation analysis revealed that 52% of survivors had compound heterozygous mutations, whereas all deaths were associated with homozygous mutations.

Conclusions: Harlequin ichthyosis should be regarded as a severe chronic disease that is not invariably fatal. With improved neonatal care and probably the early introduction of oral retinoids, the number of survivors is increasing. Compound heterozygotes appear to have a survival advantage.