Neutral lipid-storage disease with myopathy and extended phenotype with novel PNPLA2 mutation.

INTRODUCTION: Neutral lipid-storage disease with myopathy is caused by mutations in PNPLA2, which produce skeletal and cardiac myopathy. We report a man with multiorgan neutral lipid storage and unusual multisystem clinical involvement, including cognitive impairment. METHODS: Quantitative brain MRI with voxel-based morphometry and extended neuropsychological assessment were performed. In parallel, the coding sequences and intron/exon boundaries of the PNPLA2 gene were screened by direct sequencing. RESULTS: Neuropsychological assessment revealed global cognitive impairment, and brain MRI showed reduced gray matter volume in the temporal lobes. Molecular characterization revealed a novel homozygous mutation in exon 5 of PNPLA2 (c.714C>A), resulting in a premature stop codon (p.Cys238*). CONCLUSIONS: Some PNPLA2 mutations, such as the one described here, may present with an extended phenotype, including brain involvement. In these cases, complete neuropsychological testing, combined with quantitative brain MRI, may help to characterize and quantify cognitive impairment.

Neurodevelopmental profiles of children with very long chain acyl-CoA dehydrogenase deficiency diagnosed by newborn screening.

BACKGROUND: Very long chain acyl-CoA dehydrogenase (VLCAD) deficiency is a disorder of fatty acid oxidation with an estimated incidence of between 1:31,500 and 1:125,000. There is limited information regarding neurodevelopmental outcomes, probably because the disorder is perceived as affecting the skeletal and heart muscles, and many children are deemed asymptomatic. The aim of this study was to utilise a comprehensive neuropsychological assessment battery that assessed IQ, language, attention, memory, executive functioning, motor skills, behaviour, and social skills in children 4 to 10 years old diagnosed with VLCAD deficiency through newborn screening. METHOD: Seven children completed neuropsychological assessment and one child was only involved in part of the study (2 female, 6 male). Parents completed questionnaires regarding executive functioning, behaviour and social skills. RESULTS: IQ scores ranged from average to the superior range. No deficits were found in fine or gross motor skills. One patient had a mild language deficit, and two patients had previously required speech therapy. Verbal memory, attention and executive functioning skills were generally average or above. Visual memory scores were mostly above average. Parents' questionnaires identified one child as having social skills deficits, and two as having behavioural problems such as hyperactivity. One child rated high on an autism spectrum subscale; another was formally diagnosed with autism spectrum disorder-both children were symptomatic at birth. CONCLUSIONS: VLCAD deficiency does not have a significant impact on cognitive or motor skills. Some children may be vulnerable to speech, social and behavioural issues.

High cognitive outcome in an adolescent with mut- methylmalonic acidemia.

Methylmalonic acidemia is an inborn error of metabolism known to be a cause of ketoacidosis and mental retardation. The less severe mut(-) form of the disorder, however, has been described with only mild to moderate cognitive deficits or, rarely, with normal neurodevelopment in asymptomatic cases. Nevertheless, there has been no detailed documentation of long-term neuropsychological function in the mut(-) form and relatively few IQ scores. We performed longitudinal developmental and neuropsychological assessments on a girl with symptomatic mut(-) methylmalonic acidemia whose biochemical abnormalities were in the moderately severe range and who had had recurrent episodes of ketoacidosis. At almost 12 years of age, her full scale IQ on the Wechsler Intelligence Scale, third edition, was 129 with very superior and superior scores on nonverbal and verbal skills, respectively. On the National Achievement Test she scored above the 99th percentile in the Basic Battery and is considered to be a gifted student. This outcome suggests that the spectrum of cognitive attainment in mut(-) methylmalonic acidemia is wide and that even a moderate degree of biochemical severity with ketoacidotic episodes may not result in cognitive deficit. Am. J. Med. Genet. (Neuropsychiatr. Genet.) 96:192-195, 2000.

Neuropsychological outcomes in fatty acid oxidation disorders: 85 cases detected by newborn screening.

Mitochondrial fatty acid oxidation disorders include conditions in which the transport of activated acyl-Coenzyme A (CoA) into the mitochondria or utilization of these substrates is disrupted or blocked. This results in a deficit in the conversion of fat into energy. Most patients with fatty acid oxidation defects are now identified through newborn screening by tandem mass spectrometry. With earlier identification and preventative treatments, mortality and morbidity rates have improved. However, in the absence of severe health and neurological effects from these disorders, subtle developmental delays or neuropsychological deficits have been noted. Medical records were reviewed to identify outcomes in 85 children with FAOD's diagnosed through newborn screening and followed at one metabolic center. Overall, 54% of these children identified through newborn screening experienced developmental challenges. Speech delay or relative weakness in language was noted in 26 children (31%) and motor delays were noted in 24 children (29%). The majority of the 46 children receiving psychological evaluations performed well within the average range, with only 11% scoring <85 on developmental or intelligence tests. These results highlight the importance of screening children with fatty acid oxidation disorders to identify those with language, motor, or cognitive delay. Although expanded newborn screening dramatically changes the health and developmental outcomes in many children with fatty acid oxidation disorders, it also complicates the interpretation of biochemical and molecular findings and raises questions about the effectiveness or necessity of treatment in a large number of cases. Only by systematically evaluating developmental and neuropsychological outcomes using standardized methods will the true implications of newborn screening, laboratory results, and treatments for neurocognitive outcome in these disorders become clear.

[Diseases of phospholipid metabolism as possible pathogenetic factors in schizophrenia. Current findings and critical evaluation]. / Störungen im Phospholipidmetabolismus als mögliche pathogenetische Faktoren der Schizophrenie. Zusammenfassung aktueller Befunde und kritische Würdigung.

During the last few years analyses of the lipidmetabolism have been performed on schizophrenic patients. Anabolic and katabolic metabolite-concentrations from blood and cell samples have been measured. By means of new investigation techniques, such as 31P-magnetic-resonance-spectroscopy, it is nowadays even possible to determine membrane metabolites non-invasively in vivo. Arachidonic acid deficits in peripheral cell membranes, turnover of phosphodiesters in the brain, increased phospholipase A2 (PLA2)-activity in serum and blood cells, disturbed niacin-response and abnormalities of the PLA2-gene are summarised as phospholipid-membrane-hypothesis of schizophrenia. Although there is some evidence for correlations between those findings and psychotic symptoms, the connection to the pathogenesis of schizophrenia still has speculative character. Furthermore it has to be confirmed that peripheral biochemical findings acquired in schizophrenics are transferable to the metabolism of the central nervous system. Actual results of enzyme and metabolite measurements reported in literature and current findings of our own 31P-MR-spectroscopic studies are surveyed and summarised. To point out possible connections between the phospholipid-metabolism of the central nervous system and of peripheral blood-cells, systemic approaches are considered.

Outcome of medium chain acyl-CoA dehydrogenase deficiency after diagnosis.

BACKGROUND: Medium chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common inborn error of fatty acid metabolism. Undiagnosed, it has a mortality rate of 20-25%. Neonatal screening for the disorder is now possible but it is not known whether this would alter the prognosis. OBJECTIVE: To investigate the outcome of MCAD deficiency after the diagnosis has been established. METHOD: All patients with a proved diagnosis of MCAD deficiency attending one centre in a four year period were reviewed. RESULTS: Forty one patients were identified. Follow up was for a median of 6.7 years (range, 9 months to 14 years). Nearly half of the patients were admitted to hospital with symptoms characteristic of MCAD deficiency before the correct diagnosis was made. After diagnosis, two patients were admitted to hospital with severe encephalopathy but there were no additional deaths or appreciable morbidity. There was a high incidence (about one fifth) of previous sibling deaths among the cohort. CONCLUSIONS: Undiagnosed, MCAD deficiency results in considerable mortality and morbidity. However, current management improves outcome, supporting the view that the disorder should be included in newborn screening programmes.