Psychiatric manifestations revealing inborn errors of metabolism in adolescents and adults.

Inborn errors of metabolism (IEMs) may present in adolescence or adulthood as a psychiatric disorder. In some instances, an IEM is suspected because of informative family history or because psychiatric symptoms form part of a more diffuse clinical picture with systemic, cognitive or motor neurological signs. However, in some cases, psychiatric signs may be apparently isolated. We propose a schematic classification of IEMs into three groups according to the type of psychiatric signs at onset. Group 1 represents emergencies, in which disorders can present with acute and recurrent attacks of confusion, sometimes misdiagnosed as acute psychosis. Diseases in this group include urea cycle defects, homocysteine remethylation defects and porphyrias. Group 2 includes diseases with chronic psychiatric symptoms arising in adolescence or adulthood. Catatonia, visual hallucinations, and aggravation with treatments are often observed. This group includes homocystinurias, Wilson disease, adrenoleukodystrophy and some lysosomal disorders. Group 3 is characterized by mild mental retardation and late-onset behavioural or personality changes. This includes homocystinurias, cerebrotendinous xanthomatosis, nonketotic hyperglycinaemia, monoamine oxidase A deficiency, succinic semialdehyde dehydrogenase deficiency, creatine transporter deficiency, and alpha and beta mannosidosis. Because specific treatments should be more effective at the 'psychiatric stage' before the occurrence of irreversible neurological lesions, clinicians should be aware of atypical psychiatric symptoms or subtle organic signs that are suggestive of an IEM. Here we present an overview of IEMs potentially revealed by psychiatric problems in adolescence or adulthood and provide a diagnostic strategy to guide metabolic investigations.

[Neurological presentations of lysosomal diseases in adult patients]. / Présentations neurologiques des maladies lysosomales chez l'adulte.

Lysosomal diseases represent a large group of genetic storage disorders characterized by a defect in the catabolism of complex molecules within the lysosome. Effective treatments are now possible for some of them given progresses in bone-marrow transplantation, enzyme replacement therapy and substrate reduction therapy. Neurologists and psychiatrists are concerned by these diseases because they can present in adolescence or adulthood with progressive neuropsychiatric signs. Here we focus on late-onset clinical forms which can be met in an adult neurology or psychiatric department. Lysosomal diseases were classified into 3 groups: (1) leukodystrophies (metachromatic leukodystrophy, Krabbe's disease and Salla's disease); (2) Neurodegenerative or psychiatric-like diseases (GM1 and GM2 gangliosidoses, Niemann Pick type C disease, sialidosis type I, ceroid-lipofuscinosis, mucopolysaccharidosis type III); (3) multisystemic diseases (Gaucher's disease, Fabry's disease, alpha and B mannosidosis, Niemann Pick disease type B, fucosidosis, Schindler/Kanzaki disease, and mucopolysaccharidosis type I and II. We propose a diagnostic approach guided by clinical examination, brain MRI, electrodiagnostic studies and abdominal echography.

[Presentation of Niemann-Pick type C disease with psychiatric disturbance in an adult]. / Troubles psychiatriques révélateurs d'une maladie de Niemann-Pick de type C à l'âge adulte.

INTRODUCTION: Niemann-Pick Type C disease (NPC) is an autosomal recessive neurovisceral lysosomal lipid storage disorder. CASE REPORT: A 31-year-old right-handed woman had suffered from schizophrenia for 13 years. At 25 years of age, she developed a gait disorder with a static and kinetic cerebellar syndrome, dysarthria, vertical supranuclear gaze palsy and cognitive impairment. Brain MRI was normal. Abdominal ultrasonography was performed because of hypercholesterolemia and elevated transaminases and revealed hepatosplenomegaly, which in conjunction with other signs and symptoms, suggested the diagnosis of NPC. The diagnosis was confirmed by demonstration of lysosomal storage of unesterified cholesterol (filipin staining) and of a reduced rate of LDL-induced cholesterol esterification. Implication of the NPC1 gene was assessed by genetic complementation analysis. DISCUSSION: The phenotypic presentation of NPC is remarkably variable. The rarer adult-onset form has a slowly progressive course. Psychotic manifestations are often prominent and may precede neurologic symptoms. Exposure to neuroleptics delays the diagnosis of NPC. CONCLUSION: Psychotic manifestations associated with cerebellar syndrome, vertical supranuclear gaze palsy, and splenomegaly are very suggestive of NPC disease which can be reliably diagnosed on cultured skin fibroblasts by filipin staining.

Metachromatic leukodystrophy. Ultrastructural and enzymatic study of a case of variant O form.

A variant of metachromatic leukodystrophy (MLD), Austin disease, is characterized by a multiple isozyme deficiency of arylsulfatase. A 3 1/2-year-old girl with progressive mental and physical deterioration had decreased activities of arylsulfatases A and B in the leukocytes, shown by acylamide gel electrophoresis. Under the electron microscope, biopsy specimens of the brain and the peripheral nerve showed lamellar structures with socalled zebra bodies in the cytoplasmic processes of glial cells, granulo-membranous inclusions with fingerprint configurations in neurons, and myelinlike material in Schwann cells. Results from our study suggest an intricate nature of this dysmetabolic disorder, which shows ultrastructural changes usually seen in classic MLD, a deficiency of arylsulfatase A only, concomitant with those seen in mucopolysaccharidoses such as Hurler and Sanfilippo syndromes.

Lipid analysis in nerve biopsy specimens of hypertrophic neuropathy.

We performed a lipid analysis on nerve biopsy specimens in two cases of degenerative hypertrophic neuropathy. Quantitative analysis of the major lipid classes, ie, cholesterol, cerebrosides, sulfatides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine, phosphatidyl-inositol, sphingomyelin, and gangliosides, were performed. The two cases exhibited extreme decreases in levels of lipids that could be related to the very low myelin content of these nerves. Cholesterol and phospholipid levels were especially reduced. Cerebrosides and sulfatides were not modified in the same proportion, as could have been predicted from the degree of demyelination. This relative glycolipid increase could be due to the very high Schwann cell proliferation.

A new mutation in the HEXA gene associated with a spinal muscular atrophy phenotype.

We describe two adult siblings who had had mild GM2 gangliosidosis since childhood. They presented with spinal muscular atrophy and dysarthria, and one sibling also had mental disturbances. Laboratory studies established the diagnosis of the B1 variant of GM2 gangliosidosis, because the hexosaminidase (Hex) A deficiency was not present upon testing with the unsulfated synthetic substrate 4-methylumbelliferyl N-acetylglucosaminide. HEXA gene analysis proved that the patients are compound heterozygotes for the previously identified G533-->A mutation and for a new mutation, G1171-->A, at exon 11. This new mutation affects a conserved amino acid and results in a Val-->Met substitution at position 391 of the HEXA gene. Full sequence of the alpha-subunit cDNA of Hex A revealed no other mutation. Assays for Hex A activities in patients suspected of having GM2 gangliosidosis should be performed with the sulfated substrate 4-methylumbelliferyl N-acetylglucosamine 6-sulfate.

Adult sphingomyelinase deficiency: report of 2 patients who initially presented with psychiatric disorders.

We studied 2 unrelated adult patients under neuroleptic treatment who met all phenotypic and biochemical criteria for Niemann-Pick disease type B. In addition, they had chronic psychiatric disorders and low blood levels of HDL cholesterol. The marked and persistent deficiency of acid sphingomyelinase and the disturbance of sphingomyelin metabolism in skin fibroblast subcultures ruled out a pure drug-induced lipidosis. The association of Niemann-Pick disease type B with psychiatric disorders and with low levels of HDL cholesterol could be a chance association of 2 diseases, a new phenotype of Niemann-Pick type B, or the revelation by the neuroleptic treatment of a subclinical inborn sphingomyelinase deficiency.

Allele doses of apolipoprotein E type epsilon 4 in sporadic late-onset Alzheimer's disease.

Apoliprotein E, type epsilon 4 allele (ApoE-epsilon 4) is associated with late-onset sporadic Alzheimer's disease (AD). We have found that the cumulative probability of remaining unaffected over time decreases for each dose of ApoE-epsilon 4 in sporadic, late-onset French AD. The effect of genotypes on age at onset of AD was analyzed using the product limit method, to compare unaffected groups during aging.

Mutation frequencies of the cytochrome CYP2D6 gene in Parkinson disease patients and in families.

The frequencies of five mutations of the debrisoquine 4-hydroxylase (CYP2D6) gene (mutations D6-A, B, C, D, and T), corresponding to poor metabolizer (PM) phenotypes, were determined by restriction fragment length polymorphism (RFLP) and polymerase chain reaction (PCR) in 47 patients with Parkinson disease, and compared with the findings in 47 healthy controls. These mutant alleles were about twice as frequent among patients as in controls, with an approximate relative risk ratio of 2.12 (95% confidence interval, 1.41-2.62). There seem to be no significant differences in frequencies of mutant genotypes in patients among gender and modalities of response with levodopa therapy; but frequency of the mutations was slightly enhanced after age-at-onset of 60 years. Mutations D6-B, D, and T were detected in 7 patients belonging to 10 Parkinson pedigrees.

Adult-onset leukodystrophies.

Leukodystrophies are genetic metabolic diseases which generally occur in early childhood at the time of myelination. Surprisingly, these diseases can also occur during adulthood. Adult forms have various clinical presentations which reflect degenerative diseases of the nervous system. The course may last for decades. This contribution describes the main features of adult leukodystrophies and indicates those for which a biochemical and molecular diagnosis are possible. Other articles deal with their differential diagnosis of leukoencephalopathies and with the diagnostic strategy.

Familial adrenoleukodystrophy: long chain fatty acid levels and analysis with a factor VIII DNA probe.

Segregation studies of X-linked adrenoleukodystrophy (ALD) and a cloned desoxyribonucleic fragment (factor VIII gene), which detects polymorphism in the distal end of the long arm of the X chromosome (Xq28), are reported in a large sibship ALD family. The findings should permit better identification of carriers and add a new marker for identifying the ALD gene itself.

Variable number tandem repeat dopamine transporter gene polymorphism and Parkinson's disease: no association found.

We studied a variable number of tandem repeat polymorphisms in the dopamine transporter gene in search of an association with Parkinson's disease in a French population. Five alleles were detected, consisting of 7, 8, 9, 10 and 11 copies of the 40-base pair repeat sequence, of which the 10-copy allele was the most common. There was no significant difference between the patients and the control subjects in the distribution frequencies of the alleles or genotypes, or in ages at onset in patients between the main allelic classes.

Analysis of the major lipid classes in human peripheral nerve biopsies. Age group differences and abnormalities of ganglioside level in perhexiline maleate therapy.

We report here the results of a simple and reproducible technique which can be used in semi-routine analysis of peripheral nerve biopsy specimens, so as to have a quantitative analysis of the major lipid classes, i.e. cholesterol, cerebrosides, ethanolamine phospholipids, phosphatidyl-choline, phosphatidyl-serine + phosphatidylinositol, sphingomyelin and gangliosides. Glycolipid hexoses, cholesterol and total phospholipids have been compared in different age groups. Although all lipid classes increased from the younger to the older age group, the molar ratio of cholesterol to phospholipid differed less than the glycolipid to phospholipid ratio. Both increased significantly, even between age group 10--16 and older patients (36, 54, 61, 68, 72 and 73 years old). Although individual variations in lipid content are noteworthy, it must be emphasized that evolution with age of the lipid composition must be taken into account. Furthermore, this study confirms and extends earlier findings of increased ganglioside levels in some cases of peripheral neuropathies observed during perhexiline maleate therapy where characteristic lipid-like polymorphous inclusions have been demonstrated.

Improved synthesis of [1-14C]acyl-sphingosine-galactose-3-sulfate (sulfatide) for diagnosis of metachromatic leukodystrophy: usefulness of radioscanning.

We report an improved method for the radiolabelling of [1-14C 00acyl-sphingosine-galactose-3-sulfate (sulfatide), requiring preparation of lysosulfatide (sulfogalactosyl-sphingosine) by alkaline hydrolysis of sulfatide and reacylation of the sphingosine amino group with a [1-14C]stearoyl chloride. We found that the yield of labeled sulfatide could be considerably increased using stringent chromatographic conditions for the preparation of lysosulfatide and strict anhydrous conditions for the formation of the acylchloride and its coupling to lysosulfatide. Radioscanning was used at different steps to check the purity of the labeled compounds. Radioscanning was also used to determine the formation of cerebroside when measuring cerebroside sulfate sulfatase activity and sulfatide metabolism in intact fibroblasts in controls and patients with metachromatic leukodystrophy. It could demonstrate and measure with accuracy the cerebroside sulfate storage characteristic of the disease.

Prenatal diagnosis of hereditary amyloidosis in a Portuguese family living in France.

Portuguese type amyloidosis is an autosomal dominant condition caused by a mutation in the transthyretin gene. This mutation can be detected directly by the presence of a restriction site for NsiI. We report here our first prenatal diagnosis for this condition performed by chorionic villus sampling, polymerase chain reaction, and restriction enzyme digestion.

Prenatal diagnosis for the unstable CTG repeat sequence in myotonic dystrophy: a retrospective study in a French family.

The results of DNA analysis for the unstable CTG repeat are reported in a french family of myotonic dystrophy. This retrospective study confirms results obtained previously with a linked DNA marker, using the CTG repeat DNA sequence in the same family. The demonstrated possibility of predicting phenotype as well as genotype in prenatal diagnosis is important for such a disorder, were subjects may be severely affected.

Trinucleotide GAA repeat expansions in seven French Friedreich ataxia families.

We collected 7 Friedreich ataxia (FRDA) pedigrees from France. All cases but one family were homozygous for an unstable GAA trinucleotide expansion in the first intron of the frataxin gene. In this peculiar pedigree absence of the GAA expansion supports the notion of possible genetic heterogeneity of FRDA.

Trinucleotide repeat elongation in the huntingtin gene in Huntington's disease patients from 85 French families. The French HD Research Group.

IT15 is a new gene encoding a protein named huntingtin; a polymorphic CAG repeat in the proposed open reading frame of IT15 has been characterized, and an elongation of this repeat has been correlated to Huntington's disease (HD). We have investigated the CAG repeat in the huntingtin gene in 85 unrelated French families with Huntington's disease. In 79 patients (from 60 families, where at least one HD DNA was available) we found repeat lengths of 37 to 100 units, in contrast to 11 to 35 CAG's on normal chromosomes. Comparison of repeat length and age at onset of disease symptoms in 71 individuals confirms an inverse correlation (r = -0.51 for p < 10(-4)) between the age at onset and the number of CAG repeat units.

Molecular characterization of Charcot-Marie-Tooth patients in 15 pedigrees from France.

Molecular characterization of Charcot-Marie-Tooth patients in 15 pedigree from France: We collected 15 Charcot-Marie-Tooth (CMT) pedigrees from France. DNA polymorphisms analysis by Southern blotting with probes at the D17S122 locus demonstrated 17p duplication in three CMT1a families and in one sporadic case. Two families affected by CMT2 showed no evidence of the duplication.

[Presenting psychiatric and cognitive disorders in adult neurolipidoses]. / Manifestations psychiatriques ou cognitives inaugurales dans les neurolipidoses de l'adulte.

Neurolipidoses may present as psychiatric illness or dementia which may be isolated for a long time without neurological manifestations. Thus the relation with a metabolic disease may be difficult to establish. In this survey, we wish to present our clinical and biological experience in relation with lysosomal or peroxisomal disorders giving rise to neurolipidoses, a review of the literature, as well as the elements which allow to present a diagnostic strategy. We report mainly on metachromatic leukodystrophy, GM2 gangliosidosis, Fabry's disease, Niemann-Pick type C, Kufs disease, adrenoleukodystrophy, cerebro-tendinous xanthomatosis. Psychiatric symptoms may overshadow subtle signs of cognitive and motor dysfunction. Careful and persistent neurodiagnostic evaluation must be performed even in cases when CT and MRI scans are considered normal. Resistance to psychotropic drugs may be an element of orientation. The biological diagnosis is mainly biochemical. Although most of the genes involved have been cloned, many of the mutations are private, except for metachromatic leukodystrophy for which specific mutations may be related to adult cases and either with predominantly motor or predominantly cognitive and psychiatric manifestations. This review discusses also other metabolic diseases which may present as isolated or predominant cognitive and psychiatric manifestations.