Diagnosis Of Maple Syrup Urine Disease Research Articles (Page 1)

Maple Syrup Urine Disease (MSUD) and Type 1 Diabetes Mellitus (T1DM) are two distinct metabolic disorders with unique dietary management requirements. While MSUD necessitates strict restriction of branched-chain amino acids (BCAAs), T1DM requires precise carbohydrate counting to maintain optimal glycemic control. We report two cases of patients diagnosed with both MSUD and T1DM, highlighting the challenges and strategies in dietary management. Case 1, a 5-year-old girl, was diagnosed with T1DM after presenting with hyperglycemia and metabolic acidosis, despite previously stable MSUD management. The dietary regimen was modified to include a leucine-free amino acid formula and controlled carbohydrate intake to stabilize both leucine and glucose levels. Case 2, an 11-year-old boy with the diagnosis of MSUD, presented with hyperglycemia during a routine follow-up. Dietary management involved increasing the leucine-free formula while reducing carbohydrate intake to maintain metabolic control. Both cases emphasize the importance of individualized dietary plans, integrating BCAA restriction and carbohydrate regulation to prevent metabolic crises and achieve optimal glycemic control. These cases also underscore the need for a multidisciplinary approach involving pediatric endocrinologists, metabolic specialists, and dietitians to navigate the complexities of dual metabolic disorders effectively. Further studies are warranted to explore long-term outcomes and potential therapeutic targets in patients with concurrent MSUD and T1DM.

Maple syrup urine disease (MSUD) is an autosomal recessive inherited metabolic disorder, caused by branched-chain alpha-ketoacid dehydrogenase (BCKD) deficiency, leading to toxic accumulation of branched-chain amino acids (BCAAs) including leucine, isoleucine and valine and their corresponding a-ketoacids. The diagnosis of MSUD is based on elevated BCAAs and allo-isoleucine in plasma, and branched-chain hydroxyacids and ketoacids in urine. The identification of alloisoleucine >5 µmol/L is considered pathognomonic. Moreover, brain magnetic resonance imaging (MRI) showing atypical signal intensity and oedema is characteristic of MSUD. Recognition of the classical neuro-radiological findings of MSUD is particularly useful in local settings as many healthcare facilities lack the resources to measure Plasma Amino Acids (PAA). We report three cases of MSUD, in whom the disorder was strongly suspected at presentation, based on classical brain MRI findings, which was urgently confirmed by PAA analysis.

ABSTRACT:Maple syrup urine disease (MSUD) is an inborn error of amino acid metabolism secondary to enzyme defect that breaks down branched-chain amino acid (BCAA). Accumulation of these amino acids and their corresponding ketoacids in the body progresses to neurodegenerative disorders and encephalopathy in undiagnosed infants. We report a case of 46 days old baby with classical clinical and biochemical findings consistent with MSUD. Baby was investigated for inborn error of metabolism after he developed lethargy and his oral intake reduced on fifth day of life. A diagnosis of MSUD was established after analysis of plasma and CSF amino acid profile. Baby was treated accordingly and improvement in his condition was seen afterwards. KEYWORDS:Maple Syrup Urine Disease (MeSH); Amino Acids (MeSH); Amino Acids, Branched-Chain (MeSH); Infant (MeSH), Cerebrospinal Fluid (MeSH).

Implications of Maple Syrup Urine Disease in Newborns

We describe a male neonate with classic maple syrup urine disease (MSUD) in metabolic crisis. On day 7 of life, he was referred to hospital because of coma and metabolic acidosis with maple syrup odor. On day 4 after admission, brain magnetic resonance imaging findings were consistent with encephalopathy due to MSUD. Proton magnetic resonance spectroscopy ((1) H-MRS) showed a large methyl resonance peak at 0.9 p.p.m. The diagnosis of MSUD was confirmed on low branched-chain α-keto acid dehydrogenase complex activity in lymphocyte. (1) H-MR spectra were obtained in 10 min, while it took at least several days to obtain the results of other diagnostic examinations. In convalescence, the peak at 0.9 p.p.m. decreased. The large methyl resonance peak at 0.9 p.p.m. in brain (1) H-MRS would be one of the earliest clues to the diagnosis of classic MSUD in the neonatal period, especially in metabolic crisis.

Maple syrup urine disease (MSUD) is a very rare disorder of branched-chain amino acid metabolism. However, it is the most common inborn error of metabolism in the Philippines. We present a retrospective review of 21 patients diagnosed with MSUD between 1999 and 2004. The patients presented clinically between 2 and 14 days of life (mean 5 days) and the diagnosis of MSUD was established between 6 days and 11 months of age (mean 39 days). The classical burnt sugar odour was noted in the majority of patients (81%). The diagnosis of MSUD was initially based on clinical suspicion and confirmed biochemically by measurement of leucine/isoleucine levels by thin-layer chromatography. The acute management included removal of accumulated branched-chain amino acids by peritoneal dialysis in 62% of the patients. Mortality rate of this group of patients was 24% and follow-up rate was 87%. We compared this series with a previously reported series of 26 patients to determine whether diagnosis and the management of MSUD improved over the two periods. Four cases have been diagnosed early since 1992, the majority of whom had the classic form of MSUD with the onset of symptoms in the first two weeks of life. A small subset of patients with early nonspecific symptoms was diagnosed much later owing to a low-level clinical suspicion among clinicians. Overall, however, there appears to be a small but general trend towards earlier diagnosis, reduced mortality and long-term follow up in the later series. Although we are able to diagnose and manage MSUD in the Philippines, we recognize that the clinical outcome remains poor and is due mainly to late referral of cases and inadequate long-term management. In the Philippines, we recommend that all newborns who are considered to be septic, have feeding difficulties, fail to regain their birth weight or present with any other symptoms suggestive of MSUD be evaluated in the first instance by analysis of urine for ketones and if they are positive have blood collected and sent to our laboratory for leucine/isoleucine measurement.

Diagnosis of MSUD by newborn screening allows early intervention without extraneous detoxification

Computed tomography in maple syrup urine disease

Cerebral edema causing death in children with maple syrup urine disease

Although serum levels of BCAA are elevated in MSUD at the time of diagnosis, data on serum levels of amino acids prior to development of symptoms are very limited. We have measured serum levels of BCAA during the first 4 days of life in 7 neonates from 3 families with affected offsprings. Three infants had MSUD and 4 were normal. All infants received 5% glucose in water for the first 12-24 hours and then were started on a formula devoid of BCAA. Valine and isoleucine were mildly elevated in cord sera of all 3 affected infants but leucine levels overlapped with those of normal siblings. Serumlevels of all BCAA increased as early as 4 hours after birth while these levels decreased in normal infants during the same period. Isoleucine levels decreased below normal in affected infants at 2nd and 4th days of life while other BCAA continued to rise. These data indicate that diagnosis of MSUD can be made within a few hours of life even before feeding. (Supported by GCRC grant n. RR-75).