Update in Neurodegeneration with Brain Iron Accumulation: Advances in Molecular Diagnosis and Treatment Strategies

Abstract

Neurodegeneration with brain iron accumulation (NBIA) is an umbrella term used to clinically describe a group of neurologic conditions associated with high brain iron. To date, there are 10 genetic subtypes described, which share several common clinical features. Novel technologies such as improved magnetic resonance imaging techniques and whole exome sequencing have provided new clinical and genetic insight into these disorders, thereby improving clinical diagnosis for patients. Indeed, precise diagnosis is now possible for approximately 60% of patients with NBIA. Despite these genetic advances, little is known about the exact underlying disease pathways governing many forms of NBIA. In fact, for most subtypes, the causative genes and affected proteins are not directly related to iron homeostasis. Management for all subtypes remains mainly supportive and based on a multidisciplinary approach, but there are promising advances in the development of novel therapeutic strategies. Focusing mainly on the newly described NBIA subtypes, we summarize the clinical phenotypes, genetic basis, and postulated pathophysiological disease mechanisms, and propose an NBIA diagnostic pathway to guide clinical testing and genetic councelling.