Patterns of inborn errors of metabolism: A 12 year single-center hospital-based study in Libya

Background: Inborn errors of metabolism (IEM) are mostly transmitted as autosomal recessive disorders and are therefore more frequent in countries with high consanguinity rates such as in the Arab world. Objective: To study the socio-demographic characteristics and the clinical presentation of IEM in Libyan children and to shed light on our experience in dealing with these disorders. Methods: This is a descriptive case series hospital-based study of 107 children attending the Metabolic Unit at El-Khadra Teaching Hospital (MUKH) in Tripoli, Libya. The study took place between January 2001 and December 2012. Information was collected from caregivers and from all available hospital records on the following variables: age, sex, birth order, place of residence, age at onset, presenting complaints and family history of the same illness. Results: During the 12-year study period, there were 55,422 live births at El-Khadra Teaching Hospital and 107 children were diagnosed with 46 different metabolic disorders. A significantly high consanguinity rate was observed (86.9%) among parents of the affected children. Family history of previous affected children was noted in 63.5% of cases. Male to female ratio was 1.18:1. The most frequent IEM cases were amino acids disorders (25%), carbohydrate disorders (14.9%), lysosomal storage diseases (14%), organic aciduria and energy metabolic defects (9.3% each). The main clinical presentations were jaundice, hepatomegaly and seizures. Most children presented between one and six months of age (43.4%); whereas the median age at diagnosis was eight months. Thirty-eight children (35.5%) were born at El-Khadra Hospital with IEM giving a birth prevalence of 1:1458 live births, (1:6158 for aminoaciduria and 1:6927 for carbohydrate disorders). Conclusion: IEM disorders are common in Libya. Efforts to enhance awareness among pediatricians and primary healthcare providers should be supported and encouraged as many diseases are still undiagnosed. It is very important to consider IEM among all children when they present any worrying or suspicious symptoms or signs which do not respond to conventional treatment. Although our findings are preliminary, and probably the first to be conducted in Libya, they suggest ideas for decision makers to plan services including newborn screening programs and country-wide research of IEM diseases.