Newborn screening for MSUD is not mandatory in Brazil and rarely done. Children are usually diagnosed during the first weeks or months of life when they are in acute decompensation. It is difficult to evaluate the prevalence of MSUD in Brazil, since most of the newborns are still not screened for the disease. The best estimate comes from the largest private lab that does newborn screening in the country. They report 15 diagnosed cases in 1,412,671 newborns screened, or 1 in 94,178 live births (Laboratório Nobel: E. Neto, personal communication).
The most important center for the diagnosis of inborn errors of metabolism in the country is Serviço de Genética Médica at the Hospital de Clinicas de Porto Alegre (HCPA). They currently treat 8 patients with MSUD. Amino acids are analyzed using high performance liquid chromatography (HPLC). There are 3 or 4 analyzers in the country, and the turn around for results is about 10-14 days. In addition to HCPA, MSUD patients receive treatment at facilities in Rio de Janeiro, Minas Gerais and São Paulo. The oldest patient currently being treated is 6 years old.
When decompensation occurs, the child is hospitalized, the reason for decompensation is treated and anabolism is promoted (with IV fluids and BCAA-free formula feeding through NG tube if necessary and in severe cases, BCAA-free TPN). BCAA-free formula and TPN are provided by the ministry of health at no cost to the patient. Reference centers such as HCPA usually have a few cans of formula stored for emergency situations (i.e. newly diagnosed patient). It usually takes 2-4 weeks for a new patient to be enrolled in the ministry of health protocol and from then on patients receive BCAA-free formula at regular intervals free of cost. For hospitalized patients, results of BCAA analysis are usually available within 24 hours.
Information provided by:
Patricia Ashton-Prolla MD, PhD, FACMG, clinical geneticist Lilia Farret Refosco, nutricionist, MSc Roberto Giugliani MD, PhD, head of the Medical Genetics Service, HCPA Dr. Ashton-Prolla trained at Mt. Sinai Hospital in New York City under the guidance of Dr. Claude Sansaricq.
MSUD Treatment in Brazil