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Background: Tetrahydrobiopterin (BH 4 ) deficiencies comprise a group of six rare neurometabolic disorders characterized by insufficient synthesis of the monoamine neurotransmitters dopamine and serotonin due to a disturbance of BH 4 biosynthesis or recycling. Hyperphenylalaninemia (HPA) is the first diagnostic hallmark for most BH 4 deficiencies, apart from autosomal dominant guanosine triphosphate cyclohydrolase I deficiency and sepiapterin reductase deficiency. Early supplementation of neurotransmitter precursors and where appropriate, treatment of HPA results in significant improvement of motor and cognitive function. Management approaches differ across the world and therefore these guidelines have been developed aiming to harmonize and optimize patient care. Representatives of the International Working Group on Neurotransmitter related Disorders (iNTD) developed the guidelines according to the SIGN (Scottish Intercollegiate Guidelines Network) methodology by evaluating all available evidence for the diagnosis and treatment of BH 4 deficiencies., Conclusion: Although the total body of evidence in the literature was mainly rated as low or very low, these consensus guidelines will help to harmonize clinical practice and to standardize and improve care for BH 4 deficient patients.

Nonalcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease across all age groups. Obesity, diabetes, and metabolic syndrome, are the primary causes that are closely linked with the development of NAFLD. However, in young children, rare inborn errors of metabolism are predominant secondary causes of NAFLD. Furthermore, inborn errors of metabolism causing hepatosteatosis are often misdiagnosed as NAFLD in adolescents and adults. Many inborn errors of metabolism are treatable disorders and therefore require special consideration. This review aims to summarize the basic characteristics and diagnostic clues of inborn errors of metabolism associated with fatty liver disease. A suggested clinical and laboratory diagnostic approach is also discussed.

In many countries, neonatal screening programs have been unable to expand and have been limited to a few diseases. We highlight herein the opportunity available for the early detection of some inborn errors of metabolism (IEMs) in those countries in which newborn screening programs are limited. All the newborns that are referred to us for hyperphenylalaninemia are examined physically and their blood samples are checked by both high-performance liquid chromatography (HPLC) for blood phenylalanine levels and by amino acid analyzer for the measurement of blood amino acid concentrations. Seven patients who had been referred to our unit for hyperphenylalaninemia were eventually diagnosed with another IEM. A careful physical examination of the babies sent for positive screening test result combined with the utilization of low expense screening techniques at the experienced referring centers might facilitate otherwise missed opportunities for the early detection of some IEMs.

Early detection and therapy of haematological abnormalities and/or diseases may improve the prognosis of metabolic disorders. Accordingly, we aimed to evaluate the frequency and types of haematological abnormalities in children[-31pc] with various inherited metabolic disorders. The study group comprised 46 children with metabolic disorders who were followed at the Pediatric Metabolism Unit and were referred to the Pediatric Hematology Unit for evaluation of anaemia between June 2000 and 2005. The mean age of the children was 55.2 +/- 64.8 months at haematological evaluation (range 1 month-18 years, median 22.0 months); 16 were female and 30 were male. Of these 46 patients with anaemia, 25 of (54.3%) had anaemia of chronic disease (ACD), 9 (19.6%) had iron-deficiency anaemia (IDA), 7 (15.2%) had megaloblastic anaemia due to vitamin B(12) deficiency, 3 (6.5%) had chronic haemolytic anaemia, 2 (4.3%) had autoimmune haemolytic anaemia, 1 had beta-thalassaemia major, and 1 had hereditary spherocytosis. In addition to the anaemia, bicytopenia or pancytopenia was found in 8 of 46 children (17.4%). The study indicated that in organic acidaemias including methylmalonic acidaemia, propionic acidaemia, isovaleric acidaemia, and argininosuccinic acidaemia, the majority of patients had ACD (75%), which was followed by vitamin B(12) deficiency anaemia and IDA (p < 0.001). In PKU, both nutritional anaemias and ACD were present at about same frequency: 46.7% and 40%, respectively (p > 0.05). This study suggested that congenital anaemias such as hereditary spherocytosis or thalassaemias should be kept in mind as a coexisting haematological diseases in young patients with inborn errors of metabolism. In conclusion, ACD and nutritional anaemias are the most prevalent anaemias seen in patients with inborn errors of metabolism. Early detection of the disease, early administration of specific diet, and close monitoring of the patients are very important factors to prevent the development of haematological diseases in patients with inborn errors of metabolism.