Abstract
Background:Inborn errors of metabolism (IEMs) are a group of rare but potentially treatable genetic disorders. Their prevalence and patterns are particularly significant in communities with high rates of consanguineous marriage. This study aimed to present the first results from the Iran National Metabolic Registry and to analyze the frequencies, demographic patterns, and clinical outcomes of patients between 2017 and 2022.
Methods: This was a retrospective descriptive study based on the national registry. All patients with a confirmed diagnosis of IEM from 30 medical universities and referral centers for metabolic disorders who were registered in the national database were included. Inclusion criteria were a confirmed clinical/biochemical diagnosis and, when available, genetic confirmation. Cases with incomplete data or uncertain diagnosis were excluded. Collected data included demographic, clinical, laboratory, and outcome information. Descriptive statistical analysis was performed, and indicators were reported with 95% confidence intervals (CI).
Results: Between 2017 and 2022, 1,233 patients were registered in the database. After excluding 320 incomplete cases, a total of 913 patients were analyzed (51.9% male). The mean age at diagnosis was 7.2 years, with a median age of 10.3 years. Forty-four percent of patients were offspring of consanguineous marriages. The most common group of disorders was amino acid and peptide metabolism disorders (66.6%; 95% CI: 63–69%). The most frequent individual disorders were phenylketonuria (PKU, 323 cases), tyrosinemia (127 cases), and organic acidemias (111 cases in total). The reported mortality rate was 36.5%.
Conclusion: This study provides the first national report on IEMs in Iran, showing that the majority of cases involve aminoacidopathies and organic acidemias. High rates of consanguinity significantly influence the disease pattern. Expanding national registry coverage, implementing broader newborn screening programs, and strengthening genetic diagnostic infrastructure are essential.