Neurologic impairment is common in OAD and UCD, whereas the involvement of other organs (heart, liver, kidneys, eyes) follows a disease-specific pattern. The identification of unexpected chronic renal failure in GA1 and ASL deficiency emphasizes the importance of a systematic follow-up in patients with rare diseases.

The initial presentation varies widely in OAD and UCD patients. This is a challenge for rapid diagnosis and early start of treatment. Patients with a sepsis-like neonatal crisis and those with late-onset of symptoms are both at risk of delayed or missed diagnosis.

Aim To explore the clinical presentation, course, treatment and impact of early treatment in patients with remethylation disorders from the European Network and Registry for Homocystinurias and Methylation Defects (E‐HOD) international web‐based registry. Results This review comprises 238 patients (cobalamin C defect n = 161; methylenetetrahydrofolate reductase deficiency n = 50; cobalamin G defect n = 11; cobalamin E defect n = 10; cobalamin D defect n = 5; and cobalamin J defect n = 1) from 47 centres for whom the E‐HOD registry includes, as a minimum, data on medical history and enrolment visit. The duration of observation was 127 patient years. In 181 clinically diagnosed patients, the median age at presentation was 30 days (range 1 day to 42 years) and the median age at diagnosis was 3.7 months (range 3 days to 56 years). Seventy‐five percent of pre‐clinically diagnosed patients with cobalamin C disease became symptomatic within the first 15 days of life. Total homocysteine (tHcy), amino acids and urinary methylmalonic acid (MMA) were the most frequently assessed disease markers; confirmatory diagnostics were mainly molecular genetic studies. Remethylation disorders are multisystem diseases dominated by neurological and eye disease and failure to thrive. In this cohort, mortality, thromboembolic, psychiatric and renal disease were rarer than reported elsewhere. Early treatment correlates with lower overall morbidity but is less effective in preventing eye disease and cognitive impairment. The wide variation in treatment hampers the evaluation of particular therapeutic modalities. Conclusion Treatment improves the clinical course of remethylation disorders and reduces morbidity, especially if started early, but neurocognitive and eye symptoms are less responsive. Current treatment is highly variable. This study has the inevitable limitations of a retrospective, registry‐based design.

Treatment improves the clinical course of remethylation disorders and reduces morbidity, especially if started early, but neurocognitive and eye symptoms are less responsive. Current treatment is highly variable. This study has the inevitable limitations of a retrospective, registry-based design.

Objectives: The aim of the study was to describe the experience with teduglutide of several Spanish hospitals in pediatric patients with SBS (SBS). Methods: Seventeen pediatric patients with intestinal failure associated with SBS were treated with teduglutide. Patients received 0.05 mg · kg−1 · day−1 of subcutaneous teduglutide. Patients’ demographics and changes in parenteral nutrition (PN) needs, fecal losses, and citrulline level initially and at 3, 6, and 12 months were collected, as well as any adverse events. Results: Patients were receiving 55 ml · kg−1 · day−1 and 33 kcal · kg−1 · day−1 of parenteral supplementation on average at baseline (2 patients received only hydroelectrolytic solution). A total of 12/17 patients achieved parenteral independence: 3 patients after 3 months of treatment, 4 patients at 6 months, and 5 after 12 months. One patient discontinued treatment 1 year after the beginning as no changes in parenteral support or fecal losses were obtained. All others decreased their intravenous requirements by 50%. One patient suffered an episode of cholecystitis, and another one with a pre-existing cardiac disease, developed a cardiac decompensation. Conclusions: Teduglutide seems to be a safe and effective treatment in the pediatric SBS population with better results than in the pivotal study as well as in the adult population.