Homotransplantation of the liver in a patient with hepatoma and hereditary tyrosinemia.

A girl with hereditary tyrosinemia, diagnosed at 6 months of age, was treated with a diet restricted in phenylalanine and tyrosine. At 9 1/2 years of age she developed an acutely enlarged liver and spleen, and the diagnosis of hepatocarcinoma was made. The patient received a liver transplant and tyrosine metabolites became normal while she was receiving a regular diet. Three months later, an infected thrombosis of the portal vein caused her death. Liver transplant appears to be an effective method of enzyme replacement in tyrosinemia and should be considered for prevention of hepatoma.     

Effect of dietary treatment on the renal tubular function in a patient with hereditary tyrosinemia

In a 1 1/2-month-old girl with hereditary tyrosinemia, renal tubular function studies were done. The effect of a low tyrosine and phenylalanine formula on renal tubular functions was also studied. The tubular handling of phosphorus, uric acid, beta 2-microglobulin, and amino acids was disturbed. Low urinary osmolality was also seen. Creatinine clearance was increased during a period of the standard formula. Although treatment with the low tyrosine and phenylalanine diet produces dramatic improvement in plasma tyrosine and tyrosyluria, all tubular symptoms did not revert to normal. It is possible that tubular dysfunction of hereditary tyrosinemia may be irreversible changes.     

A NEW FORM OF PROLONGED TRANSIENT TYROSINEMIA PRESENTING WITH SEVERE METABOLIC ACIDOSIS

ABSTRACT: Danks, D. M., Tippett, P. and Rogers, J. (Genetics Research Unit, Royal Children's Hospital Research Foundation, Melbourne, Australia). A new form of prolonged transient tyrosinemia presenting with severe metabolic acidosis. Acta Paediatr Scand 64:209, 1975.–Yet another form of tyrosinemia is described, in a young baby who developed metabolic acidosis and ceased to grow when weaned from breast milk onto a higher protein formula. Severe tyrosyluria and mild tyrosinemia cleared on a low-protein diet which also corrected the acidosis. However, restoration of growth required a normal protein intake with very greatly reduced amounts of phenylalanine and tyrosine. The metabolic fault later resolved spontaneously at about 12 months of age. Mental development appears normal and liver disease was never apparent. The patient and her mother both excrete quite large quantities of an unidentified peptide.     

Experience and Problems of Newborn Mass Screening for Inborn Errors of Metabolism in Japan

A program of newborn mass screening for inborn errors of metabolism has since 1977 been conducted by The Ministry of Health and Welfare in Japan with great success in preventing mental and physical handicaps in children and estimating the incidence of these diseases in our country as follows: phenylketonuria (PKU) 1/78,100 maple syrup urine disease (MSUD) 1/281,200 histidinemia 1/10,600 galactosemia 1/156,200 There are some genetic variants of each of these diseases, PKU, MSUD and others. Circumspection is therefore required in making a diagnosis or selecting a particular method of treatment. When MSUD is suspected, it is necessary to make a definite diagnosis promptly and take therapeutic measures including peritoneal dialysis. The efficacy of low histidine diet in histidinemia is not yet ascertained. Close inquiries should be made about the benefit of such a dietary regimen and the long term prognosis therewith. A screening test for homocystinuria by the detection of blood methionine level is difficult. In cases with high blood methionine level during the neonatal period, it is necessary to differentiate the condition from other disease with high blood methionine. Hepatorenal tyrosinemia appears to be unsuitable for mass screening because of the the unefficacy of low phenylalanine tyrosine diet in some of the patient and the difficulty to differentiate from transient tyrosinemia in normal newborn infants. However, mass-screening is recommendable for Richner-Hanhalt type tyrosinemia which responds well to dietary therapy and which is easy to differentiate from the transient tyrosinemia because of the marked elevation of blood tyrosine.     

Surgical excision of a hepatoma complicating chronic tyrosinemia (author's transl)

A girl with chronic hereditary tyrosinemia is described in whom the diet caused an immediate resolution of tubular defect and rapid healing of the rickets. However cirrhosis was not prevented and at the age of 8 she developed a hepatoma. Complete surgical excision was possible and she remained well 15 months later. The value of blood alpha-fetoprotein levels and liver echotomography to monitor the course of the disease is emphasized. The apparent ineffectiveness of the low phenylalanine and tyrosine diet in preventing hepatic complications is discussed.     

Some biochemical effects of chloral hydrate in an infant with a tyrosinemia-like syndrome.

An infant with a combination of clinical and biochemical features resembling those found in hereditary tyrosinemia ("inborn hepatorenal dysfunction with tyrosyluria") but with spontaneous recovery is described briefly. The child also had severe congenital hydrocephalus, and was being given chloral hydrate. She was not treated by restriction of dietary phenylalanine and tyrosine. The abnormal aromatic aciduria was unaltered by ascorbic acid administration. The results of loading tests with phenylalanine, tyrosine, and sodium 4-hydroxyphenylpyruvate are compatible with the existence of a partial block in the oxidation of 4-hydroxyphenylpyruvate to homogentisate which was exacerbated by administering chloral hydrate.     

Tyrosinemia type II: Novel mutations in TAT in a boy with unusual presentation

Tyrosinemia type II is a rare autosomal recessive disorder caused by deficiency of tyrosine aminotransferase (TAT). It may occur with ocular and cutaneous symptoms with or without mental retardation, but epileptic seizure is a rare presentation of this disease. Herein we report the clinical, biochemical and genetic features of a 4‐year‐old boy who presented with afebrile seizure and photophobia. Genomic DNA was obtained from peripheral blood leukocytes from the whole family. Sequencing analysis was performed using the MiSeq next‐generation sequencing platform. Sequencing of TAT indicated two new homozygous mutations p.L312P (c.935T>C) and p.T408M (c.1223C>T) for the proband and his asymptomatic sister. During a 2 year follow‐up period, the patient had overall poor compliance with protein‐restricted diet, but his asymptomatic sister had good compliance with the diet. Cognitive function of the patient worsened steadily, but his asymptomatic sister maintained normal mental status. Tyrosinemia type II should be considered in the differential diagnosis of children presenting with epileptic seizure and photophobia; furthermore, early diagnosis and protein‐restricted regimen are important to reduce the risk of long‐term complications of tyrosinemia type II such as mental disability.     

Pregnancy in phenylketonuria: dietary treatment aimed at normalising maternal plasma phenylalanine concentration.

The transport characteristics of the placenta, which favour higher phenylalanine concentrations in the fetus than in the mother, and regression data of head circumference at birth against phenylalanine concentration at conception in maternal phenylketonuria (PKU), suggest that treatment of maternal PKU should ideally aim to maintain plasma phenylalanine concentration within the normal range throughout pregnancy. A patient with classical PKU was treated from before conception by aiming to maintain plasma phenylalanine concentration within the range 50-150 mumol/l and tyrosine within the range 60-90 mumol/l. The diet was supplemented with phenylalanine-free amino acids (100-180 g/day) and tyrosine (0-5 g/day). Plasma amino acid concentrations were monitored weekly by amino acid analyser. Dietary phenylalanine intake ranged from 6 mg/kg/day at conception to 30 mg/kg/day at delivery. Normal weight gain and fetal growth were maintained throughout the pregnancy. A normal baby was born at term with a head circumference of 35.5 cm; at 1 year of age no abnormality is detectable. These results show that with careful monitoring and compliance it is possible, and may be advisable, to maintain plasma phenylalanine concentration within the normal range in the management of PKU pregnancy.     

Hereditary tyrosinemia of chronic course without rickets and renal tubular dysfunction

Three patients with hereditary tyrosinemia type 1, two brothers and one girl, studied at the age of 5, 12 and 15 years, respectively, had neither generalized hyperaminoaciduria, glucosuria nor clinical symptoms of rickets. Untreated the elder brother had only slightly elevated plasma tyrosine level (141 mumol/l, normal less than 80), and low excretion of p-hydroxyphenyllactate. He presented with pronounced thrombocytopenia (3 X 10(9)/l). At 13 years of age he contracted hepatocellular carcinoma. The younger brother presented with serum tyrosine of 318 mumol/l and thrombocyte count 48 X 10(9)/l. Succinylacetone in urine was elevated in both, 30 and 79 mumol/mmol creatinine, respectively. The female patient was investigated for hepatomegaly in infancy, atypical tyrosinemia being considered, but afterwards developed normally without diet or any other treatment until she contracted hepatoma at the age of 15 years. Her plasma tyrosine level was 600-700 mumol/l, and she excreted large amounts of p-hydroxyphenyllactate. Succinylacetone in urine was low but elevated (8 mumol/mmol creatinine). The fumarylacetoacetase activity in fibroblasts from the brothers and in lymphocytes from the girl was less than 5% and 10% of control levels, respectively. In conclusion, the chronic form of hereditary tyrosinemia may occur without evidence of renal tubular dysfunction.     

Tyrosinemia associated with perinatal infection with cytomegalovirus.

A premature infant presented with elevated concentrations of tyrosine in blood and urine, evidence of hepatocellular damage, demineralization of the bones, and a renal Fanconi syndrome. This is the clinical picture found in hereditary tyrosinemia. The infant also had a perinatal infection with cytomegalovirus.     

Hereditary Tyrosinemia of Chronic Course without Rickets and Renal Tubular Dysfunction

ABSTRACT. Three patients with hereditary tyrosinemia type 1, two brothers and one girl, studied at the age of 5, 12 and 15 years, respectively, had neither generalized hyperaminoaciduria, glucosuria nor clinical symptoms of rickets. Untreated the elder brother had only slightly elevated plasma tyrosine level (141 μmol/l, normal <80), and low excretion of p-hydroxyphenyllactate. He presented with pronounced thrombocytopenia (3 × 10⁹/1). At 13 years of age he contracted hepatocellular carcinoma. The younger brother presented with serum tyrosine of 318 μol/l and thrombocyte count 48 × 10⁹/1. Succinylacetone in urine was elevated in both, 30 and 79 μmol/mmol creatinine, respectively. The female patient was investigated for hepatomegaly in infancy, atypical tyrosinemia being considered, but afterwards developed normally without diet or any other treatment until she contracted hepatoma at the age of 15 years. Her plasma tyrosine level was 600-700 μmol/1, and she excreted large amounts of p-hydroxyphenyllactate. Succinylacetone in urine was low but elevated (8 μmol/mmol creatinine). The fumarylacetoacetase activity in fibroblasts from the brothers and in lymphocytes from the girl was less than 5% and 10% of control levels, respectively. In conclusion, the chronic form of hereditary tyrosinemia may occur without evidence of renal tubular dysfunction.     

Diagnostic Problems of Disorders of Tyrosine Metabolism

Abnormalities of tyrosine metabolism have been reported in infants and children with a variety of liver diseases. Especially infants with hereditary fructose intolerance show often the very similar picture of clinical symptoms with congenital tyrosinemia. The livers of the patients, two cases of congenital tyrosinemia type 1 and three cases of hereditary fructose intolerance, were studied biochemically and compared to normal control livers. Kinetic studies of p-hydroxyphenylpyruvate oxidase revealed that crude extract of livers from patients with congenital tyrosinemia were distinctively inhibited by substrate in low concentration. It is suggested that this kinetic abnormality is closely related to the fundamental defect of congenital tyrosinemia. Activity of p-hydroxyphenylpyruvate oxidase was noted in peripheral leucocytes. The patient showed a reduced activity as low as 20% of normal. Enzyme assay in leucocytes might be useful in making the definite diagnosis prior to starting correct diagnosis for tyrosinemic state.     

Transient neonatal tyrosinemia: a frequent abnormality

OBJECTIVE: To evaluate the frequency of transient neonatal tyrosinemia, with or without secondary hyperphenylalaninemia,observed through neonatal screening for metabolic disorders, andthe need of monitoration and intervention with drugs and/or specialdiet in selected cases. METHODS: 457.870 dried blood samples obtained by heel stickfrom 3 to 20 days old babies were qualitatively evaluated by aminoacid thin-layer chromatography. Positive cases were quantitativelyconfirmed in serum samples by fluorimetric measurement of tyrosineand phenylalanine. RESULTS: 1.231 dried blood samples displayed positive resultsfor tyrosine in the cromatographic evaluation. The fluorimetricserum analysis disclosed normal levels of tyrosine and phenylalaninein 822 patients. The remained 409 patients showed hightyrosine levels and were placed in three groups according to thetyrosine concentration. In 118 of these cases serum phenylalaninewas also increased. CONCLUCIONS: Transient neonatal tyrosinemia is a very frequentdisorder in neonates (1/372); in some cases very high levels werefound, not only of tyrosine but also phenylalanine. As this findingis not yet accepted as absolutely harmless, the monitoration of thissituation and the use of measures to lower the tyrosine and phenylalaninelevels should be considered by the pediatrician.     

Early liver transplantation is indicated for tyrosinemia type I

Liver transplantation is now accepted as the treatment of choice for tyrosinemia type I (hereditary tyrosinemia). In an effort to determine whether any factors in these patients would aid in predicting optimal timing of the transplant procedure, we evaluated several clinical, biochemical, and radiographic parameters in five successive patients undergoing liver transplant for tyrosinemia type I at the University of Minnesota. All five patients evidenced prolonged periods of clinical and metabolic stability with dietary therapy and four of five remained stable at the time of evaluation for transplantation. Nevertheless, all five suffered significant and unexpected complications of tyrosinemia prior to the time of liver transplant. Four developed renal stones, two were in liver failure, and one developed a neurologic crisis that left him completely paralyzed. Hepatocellular carcinoma was found in one of the five at transplant. We could identify no clinical, biochemical, or radiographic study that was predictive of the likelihood of significant complications of the disorder. Survival from the transplant procedure itself was 100%. The inability to predict or prevent significant complications of tyrosinemia and the favorable outcome from transplantation lead us to recommend liver transplant for all patients with tyrosinemia type I by 12 months of age.     

Maternal phenylketonuria: report from the United Kingdom Registry 1978-97

Background: The effects of maternal phenylalanine on the fetus include facial dysmorphism, microcephaly, intrauterine growth retardation, developmental delay, and congenital heart disease. Aims: To evaluate the impact of phenylalanine restricted diet in pregnant women with phenylketonuria (PKU) on their offspring. Methods: Data on virtually all pregnancies of women with PKU in the United Kingdom between 1978 and 1997 were reported to the United Kingdom PKU Registry. The effect of the use and timing in relation to pregnancy of a phenylalanine restricted diet on birth weight, birth head circumference, the presence or absence of congenital heart disease (CHD), 4 year developmental quotient, and 8 year intelligence quotient were examined. Results: A total of 228 pregnancies resulted in live births (seven twin pregnancies were excluded). In 110 (50%), diet started before conception. For this group mean (SD) birth weight was 3160 (612) g, birth head circumference 33.6 (1.9) cm, 4 year DQ 108.9 (13.2), 8 year IQ 103.4 (15.6), and incidence of CHD was 2.4%. In comparison, for those born where treatment was started during pregnancy (n = 91), birth weight was 2818 (711) g, birth head circumference 32.7 (2.0) cm, 4 year DQ 96.8 (15.0), 8 year IQ 86.5 (13.0), and incidence of CHD was 17%. Month-by-month regression analyses suggested that metabolic control by 12–16 weeks gestation had most influence on outcome. Conclusions: Many features of the maternal PKU syndrome are preventable by starting a phenylalanine restricted diet. Women with PKU and their carers must be aware of the risks and should start the diet before conception, or as soon after as possible.     

Maternal phenylketonuria: report from the United Kingdom Registry 1978-97.

BACKGROUND: The effects of maternal phenylalanine on the fetus include facial dysmorphism, microcephaly, intrauterine growth retardation, developmental delay, and congenital heart disease. AIMS: To evaluate the impact of phenylalanine restricted diet in pregnant women with phenylketonuria (PKU) on their offspring. METHODS: Data on virtually all pregnancies of women with PKU in the United Kingdom between 1978 and 1997 were reported to the United Kingdom PKU Registry. The effect of the use and timing in relation to pregnancy of a phenylalanine restricted diet on birth weight, birth head circumference, the presence or absence of congenital heart disease (CHD), 4 year developmental quotient, and 8 year intelligence quotient were examined. RESULTS: A total of 228 pregnancies resulted in live births (seven twin pregnancies were excluded). In 110 (50%), diet started before conception. For this group mean (SD) birth weight was 3160 (612) g, birth head circumference 33.6 (1.9) cm, 4 year DQ 108.9 (13.2), 8 year IQ 103.4 (15.6), and incidence of CHD was 2.4%. In comparison, for those born where treatment was started during pregnancy (n = 91), birth weight was 2818 (711) g, birth head circumference 32.7 (2.0) cm, 4 year DQ 96.8 (15.0), 8 year IQ 86.5 (13.0), and incidence of CHD was 17%. Month-by-month regression analyses suggested that metabolic control by 12-16 weeks gestation had most influence on outcome. CONCLUSIONS: Many features of the maternal PKU syndrome are preventable by starting a phenylalanine restricted diet. Women with PKU and their carers must be aware of the risks and should start the diet before conception, or as soon after as possible.     

Oculocutaneous tyrosinosis. Report of two cases in the same family.

Clinical and biochemical evidence of oculocutaneous tyrosinosis, a rare disease due to hepatic soluble tyrosine aminotransferase (STAT) deficiency, was found in a 3 1/2-year-old girl and in her maternal aunt. Different expressivity of this disease, resulting in clinical heterogeneity, is shown to occur commonly according to the cases reported in this as well as in previous studies. The metabolic pathways leading to the unexpected excretion of phenolic acids in urine are reviewed, and the need for early diagnosis and dietary treatment, in order to prevent corneal clouding and brain damage is finally stressed.     

Dietary management of oculocutaneous tyrosinemia in an 11-year-old child

An 11-year-old girl with keratitis and plantar keratosis had tyrosinemia. The concentration of tyrosine in the plasma was 16.5 mg/dL. Dietary intake of phenylalanine and tyrosine was systematically varied, and the plasma concentrations of tyrosine and nitrogen balance were studied. It was necessary to achieve a total intake of phenylalanine and tyrosine less than 100 mg/kg/day to obtain plasma concentrations of tyrosine of less than 10 mg/dL. After dietary therapy was started, the keratitis resolved promptly, and the patient remained asymptomatic during a period of 16 months in which the mean plasma concentration of tyrosine was 11.1 mg/dL. The dietary management of a child at this age presents a different problem from that of a young infant. It can be successfully pursued at home, as well as in the carefully regulated environment of a clinical research center.     

Tyrosinemia type I—Diagnostic issues and prenatal diagnosis

A fifteen-month-old boy, born to consanguineously married couple, presented with asymptomatic hepatomegaly. Investigations revealed midly deranged liver functions, necroinflammatory changes and cirrhosis on liver biopsy, a markedly raised alpha feto protein and tyrosine levels in plasma and a generalized aminoaciduria. His diagnosis of hereditary tyrosinemia was established on findings of raised serum and urine succinylacetone, and a deficient activity of fumaryl acetoacetate hydroxylase enzyme. Prenatal diagnosis of hereditary tyrosinemia was performed in a subsequent pregnancy in this family from India.     

Contribution of extrahepatic tissues to biochemical abnormalities in hereditary tyrosinemia type I: study of three patients after liver transplantation

Three patients with hereditary tyrosinemia type I were examined before and after liver transplantation to assess the role of extrahepatic tissues in the biochemical disorders of this disease. Before transplantation the three patients excreted excessive amounts of succinylacetoacetate (SAA), succinylacetone (SA), tyrosyl acidic compounds, and 5-aminolevulinate (ALA). The activity of 5-aminolevulinate dehydratase (ALA-D) in red blood cells was markedly inhibited (1% to 5% of control) in the three patients. Successful liver transplantation resulted in decreased excretion of urinary SAA plus SA, tyrosyl acidic compounds, and ALA. Two of the patients continued to excrete significant amounts of SAA plus SA, whereas those compounds were undetectable in the urine of the third patient. Tyrosine loading resulted in increased excretion of SAA plus SA in two patients, but those compounds remained undetectable in the third. All three patients continued to excrete higher than normal amounts of ALA, but the activity of ALA-D in red blood cells returned to normal after transplantation, indicating marked clearance of SA from the blood. Liver transplantation may not totally correct the biochemical abnormalities of hereditary tyrosinemia. It is likely that the kidney is the source of persistent biochemical aberrations in the urine without significant effects on the blood. Our results suggest the existence of heterogeneity for renal involvement in hereditary tyrosinemia.