Acute Pancreatitis in a Patient with Maple Syrup Urine Disease: A Management Paradox.

Maple syrup urine disease (MSUD) is an inborn error of metabolism that causes elevated leucine in the setting of acute illnesses. We describe an 8-year-old boy with MSUD who developed acute pancreatitis and subsequent leucinosis. This case highlights the complexities of fluid management in patients with MSUD.

Management of a Woman With Maple Syrup Urine Disease During Pregnancy, Delivery, and Lactation.

Maple syrup urine disease (MSUD) is an inherited disorder of metabolism of the branched-chain amino acids leucine, isoleucine, and valine. Complications of acute elevation in plasma leucine include ketoacidosis and risk of cerebral edema, which can be fatal. Individuals with MSUD are at risk of metabolic crisis throughout life, especially at times of physiological stress. We present a case of successful management of a woman with MSUD through pregnancy, delivery, postpartum, and lactation, including nutrition therapy using modified parenteral nutrition.

The complexity of newborn screening follow-up in phenylketonuria.

In the United States, and most developed nations, the newborn screening (NBS) panel covers many primary disorders of metabolism, including phenylketonuria (PKU). When an elevated phenylalanine level is identified, the infant is evaluated for PKU and should also be tested for tetrahydrobiopterin (BH4) deficiency. A neonate presented with a phenylalanine level of 254 µmol/L (reference range <138 µmol/L) on newborn screening. The infant's confirmatory phenylalanine was 118 µmol/L (reference range <77 µmol/L). Her urine pterin profile was normal, and initially she had no measurable activity of red blood cell (RBC) dihydropteridine reductase (DHPR). Subsequent study revealed normal levels of CSF tetrahydrobiopterin and neurotransmitter metabolites, and by 18 months of age, her RBC DHPR activity was detectable at 0.5 nmol/min/mgHgb (reference range 0.8-3.9). Sequencing of the QDPR gene for DHPR revealed c.1A>T nucleotide substitution in exon 3 expressed as "p.MET1?" Phenylalanine hydroxylase (PAH) gene sequencing revealed compound heterozygosity for L249F and A300S. Although initial testing suggested the child was affected with DHPR deficiency, further analysis, finding increasing levels of DHPR activity and PAH compound mutant heterozygosity, indicated that the primary disorder is mild hyperphenylalaninemia with carrier status for DHPR deficiency. This is an example of newborn screening results leading to confusing findings requiring extensive biochemical studies and genotyping in order to arrive at the appropriate diagnosis.

Rhabdomyolysis, acute renal failure, and cardiac arrest secondary to status dystonicus in a child with glutaric aciduria type I.

An 8-½ year old boy with glutaric aciduria type I (GA1) and chronic dystonia presented with severe rhabdomyolysis in association with a febrile illness. His clinical course was complicated by acute renal failure, cardiac arrest and hypoxic ischemic encephalopathy. As acute neurological decompensation is typically not seen in patients with GA1 beyond early childhood, this case report serves as an important reminder that patients with GA1 and status dystonicus may be at risk for acute life-threatening rhabdomyolysis, renal failure and further neurological injury at any age.