Clinical and genetic diversity of congenital hyperammonemia.

Congenital hyperammonemia (HA) due to inborn errors of metabolism is a rare condition with a high rate of mortality. The main effects occur at the central nervous system (CNS) level, being neurotoxic by alteration of the neurotransmitter function. HA can be triggered by an inappropriate diet, infection or stress, but can also occur without a precise cause. In cases of metabolic crises, patients require immediately intensive care. In the last seven years (2011-2017), we cared in the Department of Genetics, "Dr. Gavril Curteanu" Municipal Clinical Hospital, Oradea, Romania, six patients with different causes of congenital HA: one case with argininosuccinate lyase deficiency, two cases (brothers) with argininosuccinate synthase deficiency, one case with non-ketotic hyperglycinemia, one case hyperglycinemia and one case with HA with unknown etiology. The medical surveillance and care of these children over a long period of time raise serious problems for the family and society. These patients are dependent on medical services: qualified medical staff (pediatrician, geneticist, radiologist, biochemist, nutritionist, and psychologist), expensive and repeated medical investigations, prolonged and costly medication. Most of these costs could be avoided by early diagnosis and treatment, rigorous monitoring of HA, ensuring proper diet and medication. Our experience regarding the clinical and genetic particularities of patients with congenital HA could be an opportunity for the better knowledge of special needs of these patients, especially regarding the psychological and social aspects.