By Karen Dolins, Editor
Heterozygote to homozygote related living donor liver transplantation in maple syrup urine disease: A case report
Liver transplantation has become more widely practiced but livers are scarce. This paper reports on a successful liver transplantation using the mother of a 2 year old child with MSUD as a donor. According to the authors, this is only the second successful case reported where a patient with MSUD received a liver from a live donor who is a heterozygous carrier (has a defective gene) for the disease. After transplant BCAA levels normalized and remained so on an unrestricted protein diet. The authors note that longer term follow-up is necessary to ensure that the child remains healthy.
Patel N et al Pediatr Transplant. 2015 Feb 10. doi: 10.1111/petr.12439. [Epub ahead of print]
Maple Syrup Urine Disease in Brazil: a panorama of the last two decades
Brazil instituted a newborn screening program in 2001, but MSUD is not one of the diseases screened for. Laboratory testing and the metabolic formula are not provided by the government health service. The authors of this study reviewed all patients diagnosed between the years of 1992 and 2011 in an attempt to inform public policy. The researchers identified 83 patients who met the criteria for a diagnosis of MSUD. Only 48 were alive at the time of the study. The age at diagnosis ranged from 7 days to 10 years. Only 12 patients were diagnosed early, defined by the researchers as by the 15th day of life. Almost half of these patients had a family history of the disease. All of those with MSUD exhibited neurological damage, including those who were diagnosed early. The authors note that this is due to the difficulties in obtaining the metabolic formula. Those who have received formula often accomplished this through legal action.
The authors make the following recommendations:
- MSUD should be included in the public newborn screening program
- Metabolic formulas should be available to all patients
- A national center specializing in liver transplantation for metabolic disorders should be established
- A network of multidisciplinary teams specializing in MSUD management should be established
Herber S Jornal de Pediatria 2014.
Urinary biomarkers of oxidative damage in Maple syrup urine disease: The l-carnitine role
It is known that high levels of leucine in the blood as well as high levels of the metabolic product alpha keto acid are responsible for the neurological damage observed in MSUD. Oxidative stress, caused by an increase in free radicals, is also thought to play a role. The body has a natural antioxidant defense system which neutralizes free radicals. Carnitine, a substance found in cells, functions as part of this system and has been studied for its potential to block some of the damage caused by free radicals.
In this study conducted in Brazil, 7 young MSUD patients who were diagnosed late were given L-Carnitine or placebo and markers of oxidative stress in their urine were observed. The researchers found that some of the children were deficient in carnitine prior to supplementation and observed a lowering of oxidative markers in the urine after 2 months of supplementation.
It is important to note that only 7 children were in the study, and all were diagnosed late as Brazil does not screen for MSUD. The researchers do not specify the time of diagnosis. Dietary compliance was not discussed, nor was their intake of food sources of antioxidants (fruits and vegetables). From the above article, we know that many do not have access to the metabolic formula. It is uncertain how this information can be applied to individuals who are diagnosed shortly after birth and who are compliant with diet. However, MSUD patients should be monitored to make sure they are not deficient in carnitine.
Guerreiro G et al International Journal of Developmental Neuroscience 2015 Feb 10. pii: S0736-5748(15)00011-8. doi: 10.1016/j.ijdevneu.2015.02.003. [Epub ahead of print]