Management of acute metabolic decompensation in maple syrup urine disease: a multi-center study.

BACKGROUND: Therapeutic modalities in acute metabolic decompensation in maple syrup urine disease (MSUD) are variable, and outcomes of each therapeutic measure have been known only individually. Factors that affect neurological outcome are not clear. METHODS: A questionnaire was sent throughout Japan to each pediatrician treating any of the 42 MSUD patients. RESULTS: Necessary information was available for 13 patients through the questionnaire, and through a publication for one patient. In nine of the 14 patients episodes of metabolic decompensation developed in the neonatal period. In the other five, the onset of disease was delayed until infancy or later. In the nine patients with neonatal onset, a pretreatment level of plasma leucine greater than 40 mg/100 mL or a duration of altered level of alertness longer than 10 days was associated with a poor neurological outcome. The therapeutic measures employed included intravenous infusion of glucose and electrolyte solution or hypertonic glucose and electrolyte solution, exchange transfusion, peritoneal dialysis, a large dose of thiamine and intravenous hyperalimentation. All patients had survived the episodes and were alive at the time of the survey. Five of the nine patients with neonatal onset have developed neurological sequelae to varying degrees. Episodes of metabolic decompensation in infancy or thereafter did not affect, or only minimally affected, the neurological outcome. CONCLUSION: Therapeutic goals to improve neurological outcome are to shorten the duration of the altered level of consciousness, and to minimize the peak plasma leucine level as much as possible.

Sequence analysis of the thyrotropin (TSH) receptor gene in congenital primary hypothyroidism associated with TSH unresponsiveness.

Congenital primary hypothyroidism due to thyrotropin (TSH) unresponsiveness is a very rare disorder and only a few cases have been documented previously. To elucidate whether structural abnormalities in the TSH receptor (TSHR) could be a primary underlying mechanism of this disorder, we analyzed nucleotide sequence of the entire coding region of the TSHR gene in three patients diagnosed with congenital primary hypothyroidism associated with TSH unresponsiveness. Diagnosis of TSH unresponsiveness was largely made based on the following criteria: (a) congenital primary hypothyroidism with autosomal recessive inheritance, (b) a nongoitrous thyroid gland in a normal position with low thyroidal radioactive iodine uptake, (c) normal in vitro TSH bioactivity or absent in vivo response to exogenous TSH, and (d) absence of thyroid autoantibodies. The TSHR cDNA was successfully obtained from RNA of peripheral mononuclear leukocytes with reverse transcription and polymerase chain reaction, and was sequenced directly. Comparison of these nucleotide sequences with the normal TSHR sequence revealed no difference in the predicted amino acid sequence with a heterozygous polymorphism in codon 601 in one patient, indicating absence of TSHR structural abnormalities in these patients. Our results indicate that congenital primary hypothyroidism associated with TSH unresponsiveness is unlikely to be due to mutations in the TSHR-structure gene.

Neonatal hypophosphatasia with elevated serum parathyroid hormone.

Two cases of neonatal hypophosphatasia are described. In case 1, hypercalcemia developed at 2 1/2 months of age and continued until death at 10 1/2 months of age. Serum calcium levels decreased transiently in response to phosphate supplementation, prednisolone, and calcitonin. Significantly elevated levels of PTH were detected at 2 1/2 months of age. At autopsy, no parathyroid glands were found. In case 2, hypercalcemia was not detected in his course. Elevated level of serum PTH was recorded on the 17th day of life. A post-mortem examination revealed the presence of one normal parathyroid gland.