The phenotypic spectrum of organic acidurias and urea cycle disorders. Part 2: the evolving clinical phenotype.

Background: The disease course and long-term outcome of patients with organic acidurias (OAD) and urea cycle disorders (UCD) are incompletely understood.

Aims: To evaluate the complex clinical phenotype of OAD and UCD patients at different ages.

Results: Acquired microcephaly and movement disorders were common in OAD and UCD highlighting that the brain is the major organ involved in these diseases.

The phenotypic spectrum of organic acidurias and urea cycle disorders. Part 1: the initial presentation.

Background: The clinical presentation of patients with organic acidurias (OAD) and urea cycle disorders (UCD) is variable; symptoms are often non-specific.

Aims/methods: To improve the knowledge about OAD and UCD the E-IMD consortium established a web-based patient registry.

Results: We registered 795 patients with OAD (n = 452) and UCD (n = 343), with ornithine transcarbamylase (OTC) deficiency (n = 196), glutaric aciduria type 1 (GA1; n = 150) and methylmalonic aciduria (MMA; n = 149) being the most frequent diseases.