Two- and three-dimensional sonographic findings of harlequin ichthyosis: case report and literature review

Background: Harlequin ichthyosis (HI) is a rare skin disorder with extremely high lethality due to a mutation of the ABCA12 gene. Because of its rarity and the often-late onset, prenatal screening for HI is extremely difficult, and most pregnant women might easily miss the period for optimal examinations. Objective: To summarize the sonographic features of HI for prenatal diagnostic purposes. Methods: The authors describe a case of HI with no family history who was diagnosed by using prenatal ultrasound scanning. The sonographic features of HI and the clinical characteristics of pregnant women were summarized by searching relevant literature over nearly two decades. Results: The unique sonographic presentations including peeling skin, clenched hands and clubfeet, ectropion, flat nose, fetal growth impairment, polyhydramnios and echogenic amniotic fluid may be primarily related to skin disorders in HI fetuses. The authors also identified a novel pathogenic ABCA12 gene mutation and explained the possible pathogenic mechanisms. Study limitations: Caution should be exercised in summarizing disease characteristics because of the small number of cases, and the authors are faced with the possibility of incomplete case searching. Conclusions: HI has relatively unique sonographic features. Therefore, 2D-ultrasound combined with 3D-ultrasound may be an effective method for the prenatal diagnosis of HI. Moreover, a novel pathogenic ABCA12 gene mutation may provide important clues for future research on the etiology of HI. However, the authors consider that additional studies are needed to provide more evidence for prenatal diagnosis. (c) 2023 Published by Elsevier Espana, S.L.U. on behalf of Sociedade Brasileira de Dermatologia. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).