Inborn Errors of Metabolism Referrals- Shahid Sadoughi Hospital: A Cross- Sectional Study

Background: Inborn Errors of Metabolism (IEMs) are a group of heterogeneous disorders resulting from absent or decreased metabolic pathway activity. They are typically rare, but are more common in consanguineous population. Methods: In this cross sectional study, all children with symptoms suspicious for IEMs who referred to Shahid Sadoughi Hospital in Yazd during a 5-year period (2013-2018) were investigated for metabolic diseases. The diagnoses were further confirmed by clinical symptoms and biochemical analysis. IEMs type, age of diagnosis, family history and disease outcome were recorded. Results: In this study, 39 symptomatic children with a median age of 48 months were diagnosed with different types of metabolic diseases. About 64.1% of the patients were born from consanguineous marriage. The patients’ mean age at the time of diagnosis was 25.3 ± 5.1 months. The most frequent disorders were organic acidemias which were found in 12 patients (30.8%), lysosomal storage disorders which were found in 8 patients (20.5%), and amino acid disorders excluding phenylketonuria which was found in 8 patients (20.5%). Most of the patients (60%) were diagnosed before the age of 6 months. Mortality from metabolic disorders was 5 (12.8%). The rest of the patients (22 cases, 56.4 %) had developmental delay. Conclusion: It was found that the prevalence of inherited metabolic disorders was higher in countries with a high prevalence of consanguineous marriage, such as Iran. More extensive newborn screening is needed for ensuring early diagnosis of these patients given that delay in diagnosis of this disorder may be associated with high morbidity and mortality.