Severe congenital cutis laxa: Identification of novel homozygous LOX gene variants in two families

We report three babies from two families with a severe lethal form of congenital cutis laxa. All three had redundant and doughy-textured skin and two siblings from one family had facial dysmorphism. Echocardiograms showed thickened and poorly contractile hearts, arterial dilatation and tortuosity. Post-mortem examination in two of the babies further revealed widespread ectasia and tortuosity of medium and large sized arteries, myocardial hypertrophy, rib and skull fractures. The presence of fractures initially suggested a diagnosis of osteogenesis imperfecta. Under light microscopy bony matrices were abnormal and arterial wall architecture was grossly abnormal showing fragmented elastic fibres. Molecular analysis of known cutis laxa genes did not yield any pathogenic defects. Whole exome sequencing of DNA following informed consent identified two separate homozygous variants in the LOX (Lysyl Oxidase) gene. LOX belongs to the 5-lysyl oxidase gene family involved in initiation of cross-linking of elastin and collagen. A mouse model of a different variant in this gene recapitulates the phenotype seen in the three babies. Our findings suggest that the LOX gene is a novel cause of severe congenital cutis laxa with arterial tortuosity, bone fragility and respiratory failure.

[Intersex: which gender should be chosen?]

A newborn infant with ambiguous genitalia is a medical emergency, and the choice of gender must take into account both the chromosomal and the gonadal sex, the hormonal milieu during fetal life, surgical aspects, the anatomy of the internal genitalia, as well as the prospects for future fertility, normal psychosexual development, and sexual function as an adult. Counselling requires paediatric endocrine, surgical, and psychological expertise, but the lack of knowledge of the long-term consequences of an intersex condition hampers rational treatment. It has long been customary to assign the child a female gender, whereas recent research points to a choice of a gender compatible with the chromosomal sex, if at all possible. This article reviews our knowledge in this field.