Newborn screening and disease variants predict neurological outcome in isovaleric aciduria

Isovaleric aciduria (IVA), a metabolic disease with severe (classic IVA) or attenuated phenotype (mild IVA), is included in newborn screening (NBS) programs worldwide. The long-term clinical benefit of screened individuals, however, is still rarely investigated. A national, prospective, observational, multi-center study of individuals with confirmed IVA identified by NBS between 1998 and 2018 was conducted. Long-term clinical outcomes of 94 individuals with IVA were evaluated, representing 73.4% (for classic IVA: 92.3%) of the German NBS cohort. In classic IVA (N = 24), NBS prevented untimely death except in one individual with lethal neonatal sepsis (3.8%) but did not completely prevent single (N = 10) or recurrent (N = 7) metabolic decompensations, 13 of them occurring already neonatally. IQ (mean ± SD, 90.7 ± 10.1) was mostly normal but below the reference population (P = .0022) and was even lower in individuals with severe neonatal decompensations (IQ 78.8 ± 7.1) compared to those without crises (IQ 94.7 ± 7.5; P = .01). Similar results were obtained for school placement. In contrast, individuals with mild IVA had excellent neurocognitive outcomes (IQ 105.5 ± 15.8; normal school placement) and a benign disease course (no metabolic decompensation, normal hospitalization rate), which did not appear to be impacted by metabolic maintenance therapy. In conclusion, NBS reduces mortality in classic IVA, but does not reliably protect against severe neonatal metabolic decompensations, crucial for favorable neurocognitive outcome. In contrast, individuals with mild IVA had excellent clinical outcomes regardless of metabolic maintenance therapy, questioning their benefit from NBS. Harmonized stratified therapeutic concepts are urgently needed.

Brain MRI features of methylmalonic acidemia in children: the relationship between neuropsychological scores and MRI findings

Methylmalonic acidemia (MMA) is a severe, heterogeneous disorder of methylmalonate and cobalamin (cbl; vitamin B12) metabolism with a poor prognosis that can cause brain damage. Identifying the magnetic resonance imaging (MRI) findings of MMA might help to make accurate diagnoses earlier in the disease course and exploring the relationship between neuropsychological scores and MRI findings, when therapy is more effective and to improve therapeutic efficacy. Cerebral MRI studies from 37 children with MMA were evaluated by a neuroradiologist. Clinical and imaging data were collected from each patient. All tests were performed during routine investigations and in accordance with the ethical principles of the Declaration of Helsinki. Informed consent was obtained from the guardians of all patients for inclusion in the study. The most common and significant findings were periventricular white matter changes (78.4%), ventricular dilation (29.7%) and cerebral atrophy (40.5%). According to the developmental quotient, the 37 patients were divided into the normal intelligence subgroup (NI, developmental quotient ≥ 85) and the low intelligence subgroup (LI, developmental quotient < 85). The incidence of corpus callosal thinning, cortical atrophy, subcortical white matter changes, and ventricular dilation (grades 0-3) was significantly higher in the LI subgroup than in the NI subgroup (P < 0.05). The incidence of no-mild and moderate-severe ventricular dilation was significantly higher in the LI subgroup than in the NI subgroup (P < 0.05). Ventricular dilatation, cerebral atrophy, white matter changes, and corpus callosal thinning are the main MRI abnormalities in MMA patients, and these manifestations are significantly correlated with delayed development in children.

Long-term clinical outcome, therapy and mild mitochondrial dysfunction in hyperprolinemia

Although hyperprolinemia type-II has a discriminative metabolic phenotype and is frequently associated with neurological system involvement, the casual relation between the metabolic abnormalities and the clinical features, except for those of the secondary B6 deficiency, has been frequently debated. In order to evaluate disease frequency and the neuro-metabolic outcome we searched our laboratory database between 1992 and 2010, including 20,991 urinary organic acid profiles. From these individuals 16,720 parallel blood samples were available, and were investigated by serum amino acid analysis. We also evaluated the clinical, neurological, psychological features, laboratory data and vitamin levels and therapeutic effect in metabolically confirmed hyperprolinemia. Due to the mitochondrial localization of both ALDH4A1 and PRODH mitochondrial enzyme complex activity was evaluated and oxygen consumption was measured to assess ATP production in patient-fibroblasts. The Mitochondrial Disease Score was used to evaluate clinical mitochondrial dysfunction. The child behavior checklist was used to screen for psychopathology. We found four patients with increased urinary P5C diagnosed with hyperprolinemia type II, and only one patient had hyperprolinemia type I. All children with hyperprolinemia type II had low normal B6 concentration, and three of the patients had biochemical markers suggesting mitochondrial dysfunction. Mitochondrial dysfunction was confirmed in a muscle biopsy in one case. Intellectual disability was found in two adolescent patients. All patients showed seizures and significant behavioral problems, including anxiety and hallucinations. The clinical course was non-progressive and independent from the B6 concentration and B6 therapy. Hyperprolinemia is a rare inborn error. Individuals with hyperprolinemia should be monitored closely due to their frequent behavioral problems.

Chronic postnatal ornithine administration to rats provokes learning deficit in the open field task

Hyperornithinemia is the biochemical hallmark of hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, an inherited metabolic disease clinically characterized by mental retardation whose pathogenesis is still poorly known. In the present work, we produced a chemical animal model of hyperornithinemia induced by a subcutaneous injection of saline-buffered Orn (2-5 μmol/g body weight) to rats. High brain Orn concentrations were achieved, indicating that Orn is permeable to the blood brain barrier. We then investigated the effect of early chronic postnatal administration of Orn on physical development and on the performance of adult rats in the open field, the Morris water maze and in the step down inhibitory avoidance tasks. Chronic Orn treatment had no effect on the appearance of coat, eye opening or upper incisor eruption, nor on the free-fall righting reflex and on the adult rat performance in the Morris water maze and in the inhibitory avoidance tasks, suggesting that physical development, aversive and spatial localization were not changed by Orn. However, Orn-treated rats did not habituate to the open field apparatus, implying a deficit of learning/memory. Motor activity was the same for Orn- and saline- injected animals. We also verified that Orn subcutaneous injections provoked lipid peroxidation in the brain, as determined by a significant increase of thiobarbituric acid-reactive substances levels. Our results indicate that chronic early postnatal hyperornithinemia may impair the central nervous system, causing minor disabilities which result in specific learning deficiencies.

Physical exercise reverses cognitive impairment in rats subjected to experimental hyperprolinemia

This study investigated whether physical exercise would reverse proline-induced performance deficits in water maze tasks, as well as its effects on brain-derived neurotrophic factor (BDNF) immunocontent and brain acetylcholinesterase (AChE) activity in Wistar rats. Proline administration followed partial time (6th-29th day of life) or full time (6th-60th day of life) protocols. Treadmill exercise was performed from 30th to 60th day of life, when behavioral testing was started. After that, animals were sacrificed for BDNF and AChE determination. Results show that proline impairs cognitive performance, decreases BDNF in cerebral cortex and hippocampus and increases AChE activity in hippocampus. All reported effects were prevented by exercise. These results suggest that cognitive, spatial learning/memory, deficits caused by hyperprolinemia may be associated, at least in part, to the decrease in BDNF levels and to the increase in AChE activity, as well as support the role of physical exercise as a potential neuroprotective strategy.

Cognitive, behavioural and adaptive profiles of children with glutaric aciduria type I detected through newborn screening

BACKGROUND

Glutaric aciduria type I (GA I) is an autosomal recessive disorder of lysine and tryptophan metabolism due to a deficiency in glutaryl-CoA dehydrogenase activity. Recent reports suggest that early diagnosis through newborn screening and initiation of preventive therapy result in improved functional outcome; however, detailed neuropsychological profiles of children with GA I are seldom reported and thus the impact of the disease on cognition, motor abilities and behaviour remains uncertain.

METHOD

We present detailed neuropsychological profiles of three children who were diagnosed with GA I through newborn screening and treated from early age, and one asymptomatic patient diagnosed through cascade screening. A comprehensive battery of standardized tests was administered including measures of intellectual function, attention/memory, executive function, motor skills, speech/language, as well as behavioural and adaptive skills.

RESULTS

The results reveal overall average cognitive outcomes; however, subtle, but significant, fine motor and articulation deficits were observed. The results are discussed with regard to potential links between fine motor deficits and speech impairments in children with GA I. Such difficulties can impact on the child's ability to engage in academic, leisure and daily activities.

CONCLUSIONS

These findings highlight the importance of in-depth assessments of all aspects of neuropsychological function in patients with GA I and provide a basis for future neuropsychological assessment in similar groups of children. In spite of relatively preserved overall functioning, using a broad range of sensitive cognitive and motor measures facilitates the detection of subtle deficits, and allows for planning of early and adequate therapeutic interventions.

Short-chain acyl-CoA dehydrogenase (SCAD) deficiency: an examination of the medical and neurodevelopmental characteristics of 14 cases identified through newborn screening or clinical symptoms

The medical and neurodevelopmental characteristics of 14 children with short-chain acyl-CoA dehydrogenase deficiency (SCADD) are described. Eight were detected as neonates by newborn screening. Three children diagnosed on the basis of clinical symptoms had normal newborn screening results while three were born in states that did not screen for SCADD. Treatment included frequent feedings and a low fat diet. All children identified by newborn screening demonstrated medical and neuropsychological development within the normative range on follow-up, although one child had a relative weakness in the motor area and another child exhibited mild speech delay. Of the three clinically identified children with newborn screening results below the cut-off value, two were healthy and performed within the normal range on cognitive and motor tests at follow-up. Four clinically identified children with SCADD experienced persistent symptoms and/or developmental delay. However, in each of these cases, there were supplementary or alternative explanations for medical and neuropsychological deficits. Results indicated no genotype-phenotype correlations. These findings suggest that SCADD might be benign and the clinical symptoms ascribed to SCADD reflective of ascertainment bias or that early identification and treatment prevented complications that may have occurred due to interaction between genetic susceptibility and other genetic factors or environmental stressors.

Psychosocial issues and coping strategies in families affected by urea cycle disorders

A survey was sent to the American members of the National Urea Cycle Disorders Foundation to ascertain the types and extent of stress imposed on families who have a child with a urea cycle defect. Forty percent of the surveys were returned. The greatest sources of stress were financial, fear of death, and the restrictions imposed by the diet. Other than removal of the economic stress and uncertainty, the results did not suggest that any specific support systems required augmentation. Instructions to mitigate frustrations occurring in emergency situations would, however, be a great help to families.

Liver transplantation for citrullinaemia improves intellectual function

BACKGROUND

Arginosuccinic acid synthetase (ASA) (EC 6.3.4.5) deficiency (citrullinaemia) (McKusick 215700) is a well-recognized cause of neonatal hyperammonaemic coma with poor long-term intellectual function, despite good medical management.

METHODS

Cadaveric hepatic transplantation was performed in a 12-year-old boy with citrullinaemia under poor biochemical control. Subsequent development of fulminant hepatic failure necessitated a second cadaveric transplant. Psychometric assessments before and after transplantation were performed using a variety of age-appropriate tests.

RESULTS

Normalization of plasma ammonium in our patient post transplantation has resulted in dramatic improvement in mental functioning and well-being and he now enjoys a normal diet. Psychometric assessment confirmed decline in his abilities prior to transplantation with particular post-transplantation improvement in perceptual organization and visuospatial abilities; these did not, however, return to normal. His family report considerable reduction in stress associated with the unpredictable nature of previous hyperammonaemic crises and recurrent hospitalization.

CONCLUSIONS

Liver transplantation should be considered as an early therapeutic option in children with citrullinaemia to prevent ongoing cerebral insult associated with hyperammonaemia.

Neonatal onset ornithine transcarbamylase deficiency: A retrospective analysis

OBJECTIVE

A retrospective analysis of 74 cases of neonatal-onset ornithine transcarbamylase (OTC) deficiency.

METHODS

The medical records of 74 of the 128 male patients referred to this center with neonatal onset OTC from 1976 to 1996 were available and analyzed.

RESULTS

Initial symptoms of OTC deficiency were nonspecific and included feeding difficulties, lethargy, and "respiratory distress"; vomiting was infrequent. Respiratory alkalosis was regularly observed; the mean pH and pCO2 were 7.5 and 24 torr, respectively. Early consideration of a metabolic disorder in those neonates with a negative family history was only 9%. Sepsis was initially misdiagnosed in 50% of the cases. For all patients the mean age at onset was 63 hours. Survival was better among those who had later onset, later diagnostic studies, and diagnosis. Apart from 1 patient whose peak ammonium level was 400 micromol/L, all surviving patients had severe developmental delay.

CONCLUSIONS

OTC deficiency should be suspected in term infants who have early signs of encephalopathy, particularly after the first 24 hours; a respiratory alkalosis is pathognomic of urea cycle disorders. Severe developmental delay is the usual outcome of OTC deficiency.

Neurodevelopmental outcome of long-term therapy of urea cycle disorders in Japan

In Japan, urea cycle disorders (UCDs) are one of the most frequent inborn errors of metabolism, estimated to have a prevalence of 1 per 50,000 live births. In an attempt to develop more effective treatment and enhance the quality of life, we investigated the clinical manifestations and prognosis of 216 patients with UCDs diagnosed and treated between 1978 and 1995. These included 92 cases of neonatal-onset UCD and 116 of late-onset UCD. Two cases of ornithine transcarbamylase (OTC) deficiency in males and 2 cases of argininosuccinase (AL) deficiency were diagnosed prospectively. By far the most common disorder was OTC deficiency, accounting for 2/3 of all cases. At the end of 1995, the 5-year survival rate was 22% for the neonatal-onset type and 41% for the late-onset type. Among the 20 long-term survivors with neonatal-onset UCD, 18 (90%) had moderate to severe neurodevelopmental deficits; this contrasts with 13 of 47 (28%) survivors with the late-onset type. In analysing 108 UCD cases, peak blood ammonia level during the first hyperammonaemic attack was correlated with neurodevelopmental outcome. When the concentration of blood ammonia was less than 180 mumol/L (5 times normal), there was no severe neurological damage. When the concentration of blood ammonia exceeded 350 mumol/L (10 times normal) at the first hyperammonaemic attack, the patients died or had severe neurological deficits. Our data point to the importance of early diagnosis and aggressive treatment.

Dietary treatment of destructive behavior associated with hyperphenylalaninemia

Behavior disorders frequently are associated with mental retardation. The most common interventions involve psychotropics, behavior modification, or both. Etiologically based treatments, derived from an understanding of underlying disease pathogeneses, are infrequent. However, several genetic diseases are associated with elevated rates of destructive responding. The hyperphenylalaninemias provide an excellent model for alternative interventions that have clear biological plausibility. A literature review is undertaken that provides the biochemical rationale for treatment with a low-phenylalanine diet. Several phenylalanine dietary control studies designed to manage aberrant responding among patients with hyperphenylalaninemia are summarized. Together they provide strong evidence that dietary phenylalanine restriction is the treatment of choice among patients ranging from classic phenylketonuria to milder hyperphenylalaninemia. Corroborating evidence derived from phenylalanine loading, magnetic resonance imaging, and dietary amino acid supplementation studies is presented.

Intellectual, neurologic, and neuropsychologic outcome in untreated subjects with nonphenylketonuria hyperphenylalaninemia. German Collaborative Study on Phenylketonuria

Based on the serum phenylalanine levels under free diet patients with hyperphenylalaninemia are classified as "classical" (>1200 micromol/L), "mild" (600-1200 micromol/L), or "non-phenylketonuria (PKU)-hyperphenylalaninemia" (<600 micromol/L). Recent studies revealed intellectual, neurologic, and neuropsychologic deficits as well as abnormalities of cerebral white matter (magnetic resonance imaging, MRI) in patients with early and adequately treated PKU. In addition deficits in IQ were reported for a group of 4-y-old patients with untreated mild PKU and non-PKU hyperphenylalaninemia (serum phenylalanine levels below 900 micromol/L). As a consequence, a lifelong diet with serum phenylalanine levels below 400 micromol/L was recommended even for those patients with serum phenylalanine levels remaining consistently between 400 and 600 micromol/L. Generally patients with non-PKU hyperphenylalaninemia were not treated, as a normal outcome was suspected, but the clinical development of patients with non-PKU hyperphenylalaninemia was not so far studied systematically. We assessed 28 untreated patients with non-PKU hyperphenylalaninemia (age: mean = 21.8, SD = 4.2 y) for IQ, school and job career, clinical-neurologic development, fine motor performances, selective and sustained attention, as well as for frontal lobe-dependent "executive functions." In addition, cranial MRI was obtained in 10 of these patients. Compared with healthy control subjects, matched for age, sex, and socioeconomic status, the patients reached normal results in all clinical and psychometric tests. Cranial MRI revealed no abnormalities. Additionally, no significant correlations between serum phenylalanine levels and test results were obtained. In the absence of any demonstrative effect, treatment is unlikely to be of significant effect in patients with non-PKU hyperphenylalaninemia.

Hydroxyprolinemia: comparison of a patient and her unaffected twin sister

Hydroxyproline is a major constituent of collagen. It accumulates as the free imino acid in a rarely reported inborn error of metabolism known as hydroxyprolinemia. This metabolic disorder was initially described in association with mental retardation, but subsequent identification in clinically normal individuals has led to the supposition that it is benign. The possibility that hydroxyprolinemia might have an adverse effect on cognitive development without producing mental retardation has not been determined nor has its incidence been reported. We prospectively studied a girl with untreated hydroxyprolinemia identified by routine neonatal urine screening, the only infant found among 1 million screened, and compared her with her unaffected dizygotic twin sister. Plasma and urine hydroxyproline were increased approximately 10-fold and 100-fold, respectively, in the affected twin. Both girls have had normal growth, with the affected twin taller than her sister. On neuropsychologic testing, the affected twin was within normal limits, performing slightly better than her sister on verbal and achievement tests but less well on visual perceptual testing. It appears that hydroxyprolinemia has caused no physical or general cognitive deficits. The possibility of an effect on visual perceptual functioning, although unlikely, cannot be eliminated.

Histidinaemia: a benign metabolic disorder

Histidinaemia is a relatively common inherited metabolic disorder with an incidence similar to phenylketonuria. This paper reports the long term outcome of patients diagnosed by newborn screening in the north west of England. Between 1966 and 1990, 108 infants were diagnosed as having histidinaemia by a regional neonatal screening programme (incidence 1:11,083). A further five children were detected following diagnosis in a sibling. Of the 113, nine were lost to follow up. Infants diagnosed before 1981 (n = 47) were placed on a low histidine diet (225 mg/kg/d) for an average period of 21 months (SD 4.5). All patients were reviewed regularly, Griffiths developmental quotients (DQ) were assessed at 2 and 4 years, and WISC-R intelligence quotients (IQ) at 8, 12, and 18 years. IQ data were converted to standard deviation scores (IQ SDS) to account for increasing IQ norms with time. Neither DQ nor IQ correlated with plasma histidine at diagnosis or with the mean plasma histidine throughout life. Growth was normal in all patients. There was no apparent benefit from a low histidine diet in early childhood. In contrast to other studies, there was no excess of clinical symptoms. On the basis of these findings, histidinaemia is a benign metabolic disorder that does not require treatment.

PAH deficiency in Italy: correlation of genotype with phenotype in the Sicilian population

The results of the neonatal screening for phenylalanine hydroxylase (PAH) deficiency in Sicily show that its incidence is higher than previously reported for mainland Italians and that non-PKU HPA is in excess of classical and mild PKU. The latter finding suggests that a high number of non-PKU HPA mutations would occur in the Sicilian population compared to populations with an inverted PKU/non-PKU HPA ratio. Previous studies have identified 40 mutations accounting for the majority (98%) of mutant alleles underlying PAH deficiency in Sicily. In order to study the molecular basis of the distribution of PAH deficiency phenotypes in the Sicilian population, we have correlated 31 of those mutations with clinical and metabolic phenotypes in 12 mentally retarded patients, 14 treated patients with classic or mild PKU, and 13 subjects presenting the non-PKU HPA phenotype. The present study proposes a tentative classification for a large number (26) of PAH gene mutations which may represent an additional tool for establishing a differential diagnosis for PAH deficiency in the Sicilian population.

Familial hypertryptophanemia in two siblings

Mild and moderate mental retardation with exaggerated affective responses, periodic mood swings, and apparent hypersexual behavior were present in two siblings with hypertryptophanemia and tryptophanuria. In addition, the male had severe myopia, a speech impediment, musculoskeletal abnormalities and perceptual hypersensitivity. His sister was deaf, which was ascribed to antenatal rubella. The occurrence in siblings and the presence of abnormal urinary tryptophan metabolite in the mother and a half-sibling suggest that the condition results from an autosomal recessive gene with minor expression in some heterozygotes.

Long-term follow-up of 58 patients with histidinemia treated with a histidine-restricted diet: no effect of therapy

OBJECTIVE

There is no general agreement as to whether or not patients with histidinemia should be treated with a histidine-restricted diet because the majority of the patients are asymptomatic. Between April 1969 and December 1986 124 children with histidinemia were detected in the Austrian Neonates Screening Program and they received long-term follow-up.

DESIGN

Fifty nine patients were treated with a histidine-restricted diet (35 mg/kg). The follow-up included determining biochemical parameters, physical examination and psychological assessment of 58 treated and 43 untreated patients. After termination of the Screening Program information about the patients' development was obtained through questionnaires and follow-up of 20 patients aged 11 to 17 years.

RESULTS

Histidine blood levels decreased after institution of the diet, but rose again after termination of the died. In the untreated patients histidine levels were highest at 1 year of age, decreasing with age. When the IQ scores of the treated and the untreated group were compared, significantly higher IQ scores were found in the 4-year-old and 6-year-old untreated patients (P < .05). Clinical symptoms were found in 27 patients; treated and untreated patients were equally affected. The clinical observations included speech defects, psychomotor and general retardation, emotional disturbances, recurrent respiratory infections, and miscellaneous symptoms such as atopic dermatitis.

CONCLUSION

We conclude that patients with histidinemia do not benefit from dietary treatment.

Long-term follow-up of 12 patients with the late-onset variant of argininosuccinic acid lyase deficiency: no impairment of intellectual and psychomotor development during therapy

To date, two variants of argininosuccinic acid lyase deficiency, the second most common enzymatic defect of the urea cycle, have been described. Most of the previous studies reported on outcomes involving neurological and intellectual impairment in affected children. This study is the first to demonstrate that the physical and mental development of such children can be normal and adequate for their age if they are treated with a low-protein diet and/or arginine supplements. Since 1973, 12 Austrian children suffering from argininosuccinic acid lyase deficiency have been detected in the Austrian Neonates Screening Program and could have been followed up. After confirmation of diagnosis, all the children were administered a daily arginine supplement (3 to 4 mmol/kg per day) in conjunction with either a normal diet or a special diet in which protein intake was restricted to 1.2 to 1.5 g/kg per day. Routine checks, including physical examination, determination of biochemical parameters, and IQ tests, were performed so the further development of these 12 patients with respect to treatment could be observed. It can be concluded that early treatment of partial argininosuccinic acid lyase deficiency results in normal intellectual and psychomotor development.

Outcome in tyrosinaemia type II

Tyrosinaemia type II was diagnosed in a boy with failure to thrive and in his sister on neonatal screening. On diet the outcome, at 12 and 10 years respectively, has been excellent in respect of oculocutaneous sequelae, growth, and psychomotor development, contrasting with the generally unfavourable outcome in most reported cases.

Neonatal citrullinaemia with satisfactory mental development

In an infant with neonatal citrullinaemia therapy was instituted on day 1 of life with a low-protein diet and oral supplements of arginine, alpha-keto-acids, essential amino acids and carnitine. The latter may have contributed to the excellent clinical outcome, as evidenced by normal growth and satisfactory psychomotor development at 3 years of age.

Teaching developmentally disabled children with chronic illness to swallow prescribed capsules

Child noncompliance with prescribed medical regimens, including nonacceptance of oral medication, frequently impedes medical treatment and achievement of clinical aims. During this study, we used a single-subject experimental design to evaluate the effectiveness of a capsule-swallowing training curriculum specifically developed to promote acceptance of oral medication by multihandicapped children. Four such children participated, each diagnosed with a chronic pediatric illness requiring daily intake of oral medication. Training consisted of verbal instruction, demonstration, reinforcement for swallowing candies/capsules progressively larger in size, ignoring mild inappropriate behavior, and gradually providing less guidance and structure. In each case, the curriculum produced routine independent swallowing of prescribed capsules/tablets. Follow-up assessments, coupled with parent satisfaction ratings, suggest that skill acquisition was both enduring and clinically significant. This study validates a brief, readily exportable, and effective approach to teaching handicapped children to swallow capsules.

[The correlation of consciousness level and the concentration of CSF ammonia in a patient with adult-type citrullinemia]

A 29-year-old man who had a taste for peanuts frequently showed abnormal behaviors. Physical examination revealed consciousness disturbance associated with flapping tremor, hypotonus in the extremities, and hypoactive deep tendon reflexes. Laboratory examination showed hyperammonemia with mild liver injury. A level of serum citrulline was 14 times higher than the upper limit of normal. A diagnosis of type 2 citrullinemia (Seheki et al) was established by the decreased argininosuccinate synthetase (ASS) in liver with low amount of ASS protein and normal kinetic properties. Diurnal fluctuation of consciousness level in this patient was not correlated with the concentration of ammonia in serum, but with that in cerebrospinal fluid. Main metabolic pathway of ammonia in brain is considered to be localized in astrocytes which have receptors for glucocorticoids. Glucocorticoids induce additional glutamine synthetase activity. Circadian rhythm of cortisol level might play a role in diurnal fluctuation of consciousness level in patients with citrullinemia.

Transient neonatal tyrosinaemia

Children who had presented with transient neonatal tyrosinaemia (TNT) were compared with a group of unaffected controls at 7-9 years of age. A comprehensive psychometric assessment revealed significant differences between the groups in adaptive behaviour, psycholinguistic abilities, and speed of learning. In nearly all components of the tests used, higher levels of TNT were associated with lower levels of performance. This study demonstrates that TNT, a condition commonly regarded as benign in the short term, has long-term effects which may be detrimental to the child in school.

[Argininosuccinic aciduria. A new case revealed by psychiatric disorders]

The case of a 4 years old boy, hospitalized for an unexplained coma, is reported. He is the first child of a non-consanguin couple. The psychomotor development of this child was considered as normal up to the age of 18 months; then, a delay in language development, behaviour disorders with an important instability interrupted by episodes of somnolence, were observed. This child was treated for psychotic disorders. At the age of 3 and half, he had two episodes of seizures associated with fever. He was hospitalized for a 24 hours coma (4 years old). An hepatomegaly and a dry, brittle hair were then observed. Hyperammonemia was made obvious by a protein tolerance test. The diagnosis of argininosuccinate lyase (ASAL) deficiency was based on the increased levels of ASA in plasma and urine. The deficiency was proved by a fibroblast culture. With protein restriction, hepatomegaly disappeared, hair became normal, the behaviour disorders and the delay in language development was improved. However, some school difficulties persist. This case shows that an hereditary metabolic syndrome can be revealed by psychotic like symptoms in childhood.