Pathomechanisms of harlequin ichthyosis and ABCA transporters in human diseases.
OBJECTIVE
To review recent advances in our understanding of the genetic pathomechanisms of harlequin ichthyosis (HI) (the most devastating subtype of congenital ichthyoses) and its prenatal diagnosis and to discuss the possibility of future gene therapy.


METHODS
PubMed search for articles about HI, its causative protein adenosine triphosphate-binding cassette A12 (ABCA12), and related molecules.


METHODS
English-language studies were selected if they provided useful information about the pathomechanisms of HI and ABCA lipid transporters.


RESULTS
This article describes ABCA12 as a causative molecule involved in defects in HI, summarizes the known genetic disorders caused by genetic defects in ABCA lipid transporters, and highlights the prospects of prenatal diagnosis and gene therapy for HI.


CONCLUSIONS
Harlequin ichthyosis is caused by a serious functional deficiency of ABCA12. ABCA12 and ABCA3 are essential lipid transporters for human adaptation to a dry terrestrial environment. In clinical practice, information regarding the genetic defects and pathomechanisms underlying HI is important for precise diagnosis, genetic counseling, and prenatal diagnosis.
Akiyama
Masashi
M
Department of Dermatology, Hokkaido University Graduate School of Medicine, Sapporo, Japan. akiyama@med.hokudai.ac.jp
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D017490:Ichthyosis, Lamellar / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology; D007231:Infant, Newborn; D009154:Mutation; D011247:Pregnancy; D011296:Prenatal Diagnosis
D018528:ATP-Binding Cassette Transporters