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The discovery that a natural product leptospermone had herbicidal activity formed the starting point for chemical synthesis to find more activity and selectivity. A series of molecules called triketones were found to possess good activity and 2-(2-nitro-4-trifluoromethylbenzoyl)-cyclohexane-1,3-dione (NTBC) was selected for toxicology testing. NTBC fed at low doses to rats and dogs caused keratopathy, which on cessation of the diet recovered. Mice, rabbits and monkeys fed NTBC did not show this response. Research discovered that NTBC caused tyrosinaemia which was due to inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase in both mammals and plants thereby finding a novel target for killing plants. NTBC was also used sucessfully as a drug to treat a rare inborn error of metabolism, tyrosinaemia type I, in collaboration with Professor's Sven Lindstedt and Elisabeth Holme. Understanding the mechanism of toxicity of NTBC led to novel herbicide discovery and saved the lives of children with acute tyrosinaemia type I.

The continued expansion of newborn screening programmes to include additional conditions increases the responsibility of newborn screening laboratories to provide testing with the highest sensitivity and specificity to allow for identification of affected patients while minimizing the false-positive rate. Some assays and analytes are particularly problematic. Over recent years, our laboratory tried to improve this situation by developing second-tier tests to reduce false-positive results in the screening for congenital adrenal hyperplasia (CAH), tyrosinaemia type I, methylmalonic acidaemias, homocystinuria, and maple syrup urine disease (MSUD). Beginning in 2004, this approach was applied to Mayo's newborn screening programme and resulted in a false-positive rate of 0.09%, a positive predictive value of 41%, and a positive detection rate of 1 affected case in 1672 babies screened.

NTBC has revolutionized the management of tyrosinaemia type I, although animal experiments have shown that long-term administration may produce corneal opacities analogous to those in tyrosinaemia type II. We have assessed the prevalence of ocular side-effects in 11 tyrosinaemia type I patients on NTBC attending the Birmingham Children's Hospital. Despite high plasma tyrosine concentrations in some patients, they did not experience symptoms or signs of ocular toxicity.

Neurological crises do not occur in patients with tyrosinaemia type I treated with NTBC. We report an 8 month-old boy with severe neurological crisis after interruption of NTBC treatment including progressive ascending polyneuropathy and diaphragmatic paralysis, arterial hypertension, respiratory distress requiring mechanical ventilation who later also developed impaired liver function and tubulopathy. After re-introduction of NTBC the patient slowly regained normal neurological functions and recovered completely.

From 3–4 June, 2016, the 23rd Annual Meeting of the German Society for Newborn Screening (Deutsche Gesellschaft für Neugeborenenscreening, DGNS) was held at the University Hospital Heidelberg. The meeting was organized by PD Dr. med. Gwendolyn Gramer (conference president) from the Newborn Screening Centreat the University Hospital Heidelberg, Centre for Paediatric and Adolescent Medicine. Prof. Dr. med. Prof. h.c. mult. (RCH) Georg F. Hoffmann, PD Dr. phil. nat. Jürgen G. Okun and PD Dr. med. Gwendolyn Gramer formed the scientific board for the selection of presentations. Abstracts of plenary lectures, oral communications, and posters presented during the meeting are collected in this report.

The rapid development of new modes of treatment including organ transplantation, enzyme inhibition, enzyme replacement, liver cell transplantation and gene therapy necessitates knowledge about the results of all modes of treatment to allow decisions on treatment strategies. In hereditary tyrosinaemia type I, apart from the dietary treatment, both orthotopic liver transplantation (OLT) and treatment with 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) have become available (Lindstedt et al 1992). However, this disease seems clinically very heterogeneous. Therefore, we should first attempt to categorize different clinical forms since treatment strategies may be quite different. Based on clinical heterogeneity, Halvorsen (1990) divided patients with tyrosinaemia into three forms - acute, subacute and chronic - but could not report the exact outcome on dietary treatment with possible consequences for treatment strategies. We have therefore investigated the clinical course on dietary treatment of our own patients and conducted an international survey on the clinical course of patients managed by dietary treatment and/or OLT, of which the results in part are described elsewhere (van Spronsen et al 1994). The results may enable us to compare the outcome on NTBC and to decide on treatment strategy in tyrosinaemia type I patients.

A 19 year old woman with tyrosinaemia type 1 gave birth to a healthy girl after 41 weeks of gestation. Nitisinone was continued throughout the pregnancy (maternal levels 68-96 μmol/l, target level 30-60 μmol/l). Tyrosine levels during pregnancy were between 500 and 693 μmol/l (normal values 20-120 μmol/l) and phenylalanine levels between 8 and 39 μmol/l (normal values 30-100 μmol/l). Nitisinone was measurable in neonatal blood immediately after birth, at a level comparable to the simultaneous level in the mother. Nitisinone half-life in the neonate was estimated to be 90 h. Tyrosine levels in the neonate decreased from 1,157 μmol/l at birth (cord blood) to normal levels within 4 weeks. Phenylalanine levels in the neonate were normal from birth on. The child had a normal psychomotor development as assessed throughout the first year of life.This is the first report worldwide of a pregnancy during treatment with nitisinone.In this case, no adverse effects of nitisinone, maternal high tyrosine or low phenylalanine were detected in the child, so far. Long-term results in a larger cohort of pregnancies and births are needed to determine whether nitisinone can be administered safely during pregnancy.

Background Quantification of nitisinone, 2-(nitro-4-trifluoromethylbenzoyl)1,3-cyclohexanedione (NTBC) has been repeatedly described. Nevertheless monitoring of NTBC has not yet become part of routine therapy surveillance in tyrosinaemia type I (OMIM 276700 ). We developed a blood spot test to facilitate collection and transport of samples. Furthermore, the test material can be used for determination of other parameters like tyrosine and succinylacetone. Method For quantification of NTBC in blood spots filter paper discs of 3.2 mm diameter were extracted with 150 μL methanol containing mesotrione as internal standard (IS). Analysis was done by UPLC–MS/MS on a Xevo mass spectrometer (ESI+), (MRM). Parent ions were 330.05 for NTBC and 340.05 for IS, daughter ions were m/z 217.95 and m/z 125.95 for NTBC, and m/z 227.95 and m/z 103.95 for IS. Results The calibration curve for NTBC in blood spots was linear from 0.1 μmol/L to 100 μmol/L. Recovery exceeded 73.1%, CV intraday and interday were below 9.6%. Instrumental run time was 2.5 min. Sensitivity of the method was 0.1 μmol/L. NTBC concentrations in plasma were higher than in blood spots by a factor of 1.56 ± 0.13. Conclusion As demonstrated in patients with tyrosinaemia type I quantification of NTBC by UPLC–MS/MS in blood spots is feasible and gives valuable information for monitoring NTBC treatment.

Tyrosinaemia type I (TTI) is an inherited multisystemic disorder of tyrosine metabolism. In addition to hepatic and renal involvement, cardiomyopathy is an important clinical manifestation. Objective: To evaluate the incidence and outcome of cardiomyopathy in TTI. Subjects and methods: A retrospective study was performed of 20 consecutive children with TTI (12 male, 8 female) referred to a single centre between 1986 and 2002. All were initially treated with standard dietary therapy and, since 1992, with nitisinone. The indications for orthotopic liver transplantation (LT) changed during the study. Serial echocardiography was undertaken in all subjects. Results: 9/20 (45%) children had an acute hepatic presentation. Five (25%) received dietary treatment followed by LT, and 14 (70%) were treated with nitisinone at presentation. 6/20 (30%) had cardiomyopathy at initial assessment, with interventricular septal hypertrophy being the commonest finding (5/6). Cardiomyopathy was significantly less common in those treated initially with nitisinone. After a median follow-up of 3.6 (0.45–13.5) years, 5/6 (83%) had complete resolution of cardiomyopathy and 1/6 showed significant improvement. No child with a normal initial echocardiography subsequently developed cardiomyopathy. Conclusion: Cardiomyopathy is a common manifestation of TTI and it has a favourable long-term outcome. Children initially treated with nitisinone are less likely to develop this complication.

We report the case of a child who developed severe obstructive hypertrophic cardiomyopathy revealing hereditary tyrosinaemia type I, who was successfully treated with NTBC. The mechanisms underlying the association are discussed.

UNLABELLED Despite the introduction of NTBC into the treatment of tyrosinaemia type I (TT1) and a considerable improvement in the outcome of these patients, the principal risk of developing hepatocellular carcinoma (HCC) in this metabolic disorder remains mainly in those children with late introduction of NBTC after the second year of life. Serial total alpha-Fetoprotein (AFP) levels are used to evaluate the individual risk to develop malignant changes. A failure of AFP to decrease on adaequate treatment or a secondary increase after a period of falling levels have been an indication for liver transplantation. Lectin-reactive alpha-Fetoprotein is a recently described marker to distinguish hepatocellular carcinoma from benign liver disease in adult cirrhotic patients. AIMS To investigate if the analysis for Lectin-reactive alpha-Fetoprotein would lead to earlier detection of HCC compared to a judgement based on the evolution of standard total AFP alone. PATIENTS We report the analysis of 12 patients with TTI and histologically proven HCC. There of 5 were diagnosed under one year of age, but NTBC treatment was started between 2 years 3 month and 7 years of age except in one case in which NTBC was introduced when the diagnosis of TTI was made. The remainder of the patients cover up to the age of 15 years. All patients had been treated with NTBC. METHODS Lectin containing agarose gel for AFP electrophoresis leads to AFP separation according to different affinities of the varying carbohydrate chains of AFP to lectins. RESULTS AFP subfractions could be identified in all 12 patients. In 6 patients the L3-AFP rose before the total AFP. In 3 patients the rise in L3-AFP was consistent with the rise of the total AFP and in 3 patients the L3-AFP was raised after the total AFP or did not increase at all. DISCUSSION We were able to identify 6 out of 12 patients who had an early increase of L3-AFP before they developed a change in total AFP levels. The clinical significance of these early changes need to be determined. Lectin-affinity electrophoresis may have a potential role as an additional tool that may help to discriminate benign liver disease from HCC in TTI. CONCLUSIONS We suggest the further evaluation of lectin-reactive AFP in TTI.

Tyrosinaemia type I (TT I) (McKusick 276700) is a heterogeneous disorder with a broad spectrum of clinical phenotypes. Although histological abnormalities of the pancreas are well recognized, there are only incidental reports of pancreatic dysfunction manifested as insulin-dependent diabetes mellitus. We report three subjects with TT I and acute liver dysfunction who had hyperinsulinism in early infancy. Hypoglycaemia persisted despite dietary treatment and one patient had inadequate lipolysis at the time of hypoglycaemia. All three patients were successfully treated with diazoxide (10 mg/kg per day) and chlorthiazide (35 mg/kg per day) and treatment was gradually withdrawn after 9, 13 and 34 months, respectively. The mechanism of pancreatic dysfunction in TT I is unknown but may be related to the toxic metabolites that accumulate in this condition. We conclude that hyperinsulinism is not a rare complication in TT I. In patients with persistent hypoglycaemia, C-peptide should always be measured. Treatment with diazoxide and chlorthiazide is highly effective, appears to be safe, and does not need to be continued lifelong.

A 21-month-old girl suffering from tyrosinaemia type I and undergoing treatment with 2-(2-nitro-4-trifluoro-methylbenzoyl)-1,3-cyclohexanedione (NTBC) presented with pruritus which rapidly ceased with administration of high doses of ursodeoxycholic acid. Determination of plasma bile acids revealed clearly elevated levels both in samples taken before and after the onset of NTBC therapy, thus indicating, that the increase was not related to the administration of this drug. This result is corroborated by data from the first patient's newborn sister, diagnosed with the same disease, who showed elevated plasma bile acid concentrations in all samples examined, except for the cord plasma. This is the first report on altered bile acid concentrations in tyrosinaemia type I, and underlines the need for thorough investigation of bile acid metabolism in this disease.

AIMS: To assess the incidence of tyrosinaemia type I in the West Midlands Region, and the value of current neonatal screening programmes for phenylketonuria (PKU) for its detection. METHODS: Retrospective study of results from the PKU neonatal screening programmes in Birmingham (using plasma amino acid chromatography) and in the rest of the West Midlands (using the Guthrie microbiological assay for blood spot phenylalanine) was carried out between January 1985 and March 1994. Patients with tyrosinaemia I born in the region during the same period were identified from a regional database of patients with confirmed inherited metabolic disease. The study was carried out in a specialist children9s hospital; the regional centre in the West Midlands for neonatal screening and investigation of inborn errors, and a supraregional centre for liver transplantation and management of paediatric liver disease. RESULTS: Amino acid chromatography showed increased tyrosine in 447 of 145,444 neonates born in Birmingham; this was still increased at 6 weeks of age in six cases. Five had tyrosinaemia I; the sixth had tyrosinaemia type III. Two others in whom amino acid chromatography was considered normal have since presented with tyrosinaemia I. Outside Birmingham, 525,151 children were screened using the Guthrie test. Five have presented clinically with tyrosinaemia I; screening did not contribute to diagnosis in any case. The incidence of tyrosinaemia I was 1 in 20,791 live births within Birmingham and 1 in 105,037 outside. Of the total 12 patients in the West Midlands with tyrosinaemia I, 10 (83%) were of non-oriental Asian ethnicity; the incidence of tyrosinaemia I was 3.7/10(6) head of population in this group and 0.04/10(6) in the rest of the population. CONCLUSIONS: Asians in the West Midlands have a high incidence of tyrosinaemia I. Neonatal PKU screening using amino acid chromatography may contribute to diagnosis and early treatment.

Dietary treatment cannot prevent a lethal outcome in many patients with hereditary tyrosinaemia type I (van Spronsen et al 1994). Therefore, until the discovery of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3-cyclohexanedione (NTBC) as a potential drug (Lindstedt et al 1992), orthotopic liver transplantation (OLT) was the only definitive treatment in patients with this disease (van Spronsen 1989). We report our experiences with OLT in 9 patients with tyrosinaemia type I.

This study reports the development of a mutation screening strategy for tyrosinaemia type I, and the identification of six novel mutations in the FAA gene.

I. TAVARES DE ALMEIDA l, P. P. LEANDRO 1, M. F. B. SILVA 1, C. SILVEIRA l, A. DA SILVA 2, J. SALAZAR DE SOUSA 2 and M. DURAN 3 1Centro de Metabolismos e Genktica (LN.LC.), Faculdade de Farmdcia, 1600 Lisboa, Portugal, 2 paediatric Gastroenterology Unit, Sta. Maria Hospital, Faculdade de Medecina, Lisboa, Portugal; 3 University Children's Hospital, Het Wilhelmina Kinderziekenhuis, Nieuwe Gracht 137, NL-3512 LK Utrecht, The Netherlands