Rare clinical case of harlequin ichthyosis: opportunities and difficulties of prenatal diagnosis.

Objective: Harlequin ichthyosis (MIM 242500) is a rare autosomal recessive skin disorder caused by a congenital disorder of epidermal keratinization and associated with a mutation in the ABCA12 gene of chromosome 2q35. We report a case of a fetus at 25 weeks of gestation with harlequin ichthyosis and a deletion of chromosome 15q11.2-q12. Case(s): The results of an ultrasound examination at 13 weeks 2 days and 18 weeks of pregnancy showed no pathology. Two previous male children were presumably born with harlequin ichthyosis (genetic diagnosis was not performed due to unavailability at that time) and died on the first day of life. Analysis of amniotic fluid using SNP - array technology at 23 weeks revealed a deletion of 15q11.2-q12. Subsequent ultrasound examination at 25 weeks of pregnancy showed signs of harlequin ichthyosis, including an abnormal flat facial profile, a constantly open large mouth, and a large number of inclusions in the amniotic fluid. Considering the family history, a diagnosis of harlequin ichthyosis was made, leading the family to decide to terminate the pregnancy. A male child was born, weighing 800 g, with a typical harlequin ichthyosis phenotype, and died 2 hours after birth. Conclusion: In case of a suspicion of this disease in a family, prenatal diagnosis of harlequin ichthyosis can be carried out by prenatal chromosomal microarray analysis using tissue obtained from chorionic villus sampling, amniocentesis or cordocentesis in the early terms of pregnancy. Ultrasound signs of the disease typically manifest after 24 weeks of pregnancy. [ABSTRACT FROM AUTHOR]