Professor in Pediatrics, UP College of Medicine
Director, Institute of Human Genetics - National Institutes of
Health, University of the Philippines Manila
The Philippine delegation at the MSUD Symposium, 2008
The incidence of MSUD in the Philippines is not known. The first patient with MSUD in the Philippines was diagnosed in 1992. The 7 day old boy presented with the characteristic odor. Of the 76 cases identified since 1992, only 20 are still alive. The majority are diagnosed when signs of metabolic decompensation have set in. One patient was diagnosed as early as the 2nd day of life. Mom had another child with MSUD and she noted the ‘typical sweet odor’ while breastfeeding this baby.
The first major challenge is the early diagnosis of the babies with MSUD. The early symptoms of poor appetite/feeding, irritability and incessant crying mimic neonatal sepsis, a very common condition among sick neonates in the Philippines. A wrong diagnosis is made unless the physician has a high suspicion of MSUD. Most of the older patients were diagnosed late with onset of complications. The more recently diagnosed patients have better performance.
Most physicians are not aware of MSUD. In the Philippines, more than 60% of newborns are home-delivered and are attended by midwives and traditional birth attendants who also cannot recognize the early signs of MSUD. We suspect that many more babies with MSUD are born but are misdiagnosed as having infection and succumb to death without proper evaluation.
The second major challenge is the cost of the diagnostic examination. MSUD is not yet included in the newborn screening panel. Plasma level determination of leucine, isoleucine and valine is very costly (US$180). Cheaper alternatives for diagnosis are 1) urine metabolic screening using high voltage electrophoresis which show distinct bands for branched chain amino acids (US$60); 2) Thin Layer Chromatography (TLC) (US$6); and 3) Urine screening for 2,4 dinitropheynyl-hydrazine (US$12). TLC is the most commonly used. All these are generally not affordable for the majority of the families of MSUD patients earning minimum wages of US$ 8 a day.
Since most families are young, the third major challenge is diagnosis in subsequent pregnancies. MSUD is always considered in succeeding pregnancies of mothers with affected children. Out of the 76 patients identified, 36 families have agreed to undergo mutation analysis. Results showed that 40% of the patients have a novel mutation specific to the Filipino population. Families with known mutations are offered testing for subsequent children at birth. If confirmed positive with mutation analysis, nutritional management is started immediately. If negative for the family mutation, the patient is cleared and started with unrestricted breastfeeding and regular formula. If the family mutation is NOT available, the newborn is subjected to protein challenge guided by leucine level monitoring.
The fourth major challenge is acute and long term management. The majority of the patients undergo peritoneal dialysis as the method for rapid removal of toxic substances. In the Philippines, not all nephrologists are comfortable with dialysis in a neonate and not all tertiary hospitals are capable of handling acute management of MSUD. MSUD milk formula is not readily available in the Philippines. Although Mead Johnson donates several boxes to the group of patients, the supply is not enough and parents have to buy MSUD special formula which costs US$70 per can, inclusive of taxes and shipping. A major crisis happened last year when Mead Johnson did not provide milk for several months. The donation of the MSUD Support Group USA was very timely.
A volunteer dietitian assists with the preparation of special low protein menus using local food items. Special food items are likewise not available in the country. And even if made available, the cost of these special food items are not affordable to the families.
The fifth major challenge is follow-up of patients, which is very critical for MSUD management. Not all patients are following up regularly. Not all patients are following the dietary protocol. Not all patients are undergoing therapy. There are only a few clinical geneticists in the country and they are concentrated in Metro Manila, A Metabolic Clinic at the Philippine General Hospital (PGH), the University teaching hospital organizes the follow up of the patients as well as coordinates with the donated milk formula with Mead Johnson. Only1 other metabolic clinic (Cebu) exists outside of Metro Manila.
The sixth major challenge is securing support from government. The Institute of Human Genetics at the National Institutes of Health- Philippines has been the main institution that has been helping the MSUD families with access to diagnostic and treatment options. In 1993, an informal support group among MSUD family members was established. The families have been supporting each other during crises on MSUD milk shortage. They offer emotional support to new families. Sharing of recipes is an interesting activity of the families. This group was formalized in 2006 as the MSUD Parent Support Group and eventually joined the Philippine Society for Orphan Disorders, an umbrella organization that addresses the needs of patients with rare genetic disorders.
The challenges in the Philippines may be difficult to overcome but the professionals and the families have continued to face them with optimism. There are preliminary discussions on the inclusion of MSUD in the newborn screening panel. President and General Manager Paul Richards of Mead Johnson Philippines recently committed to provide a complete supply of MSUD special formula to the 20 living patients. There are efforts to set up an endowment fund to secure the needs of the patients and future babies with MSUD under Philippine Society for Orphan Disorders.