Lethal Osteogenesis Imperfecta–Like Condition with Cutis Laxa and Arterial Tortuosity in MZ Twins Due to a Homozygous Fibulin-4 Mutation

Abstract

This case report involved male infants of a size consistent with the estimated gestational age of 31 weeks. The mother of the twins was a 27-year-old, G4P3 woman with limited prenatal care who presented for cesarean delivery. Resuscitation efforts were initiated and continued until the infants became asystolic. Postmortem radiographs showed innumerable fractures of the limbs, ribs, and skull in various states of healing with callus formation; hence, the fractures were of prenatal origin. Despite the fractures, the growth of the long bones was not impaired. The radiographic findings were initially thought to represent osteogenesis imperfecta type IIC. However, there were also vascular anomalies not explained by this phenotype. Grossly, all arteries were elongated, thickened, and tortuous. The carotids, descending aorta, and iliac arteries were redundant to such an extent that they produced corkscrew patterns. There was also cutis laxa with loose, redundant skin over the entire body. Collagen genes did not show any mutations; however, when it was suggested Fibulin-4 be studied because of overlap with the condition described by Dasouki and colleagues in 2007, a homozygous premature stop codon mutation was found in that gene.