Harlequin ichthyosis (HI) is a rare and severe form of the autosomal recessive congenital ichthyosis. This is a case report of a 30-year-old healthy woman with a pregnancy resulting in preterm birth of a child with severe HI, who did not survive. At the autopsy, the child was found with HI and a diaphragmatic hernia of the Bochdalek type. Genetic analysis showed, that the child was homozygous for the mutation c.5121_5124del in ABCA12. The parents were related and were found heterozygous of this mutation. This clinical presentation with this new mutation has not been described in the literature before.