Very Long-chain Fatty Acids Levels Research Articles

Inactivation of the Peroxisomal Multifunctional Protein-2 in Mice Impedes the Degradation of Not Only 2-Methyl-branched Fatty Acids and Bile Acid Intermediates but Also of Very Long Chain Fatty Acids

According to current views, peroxisomal beta-oxidation is organized as two parallel pathways: the classical pathway that is responsible for the degradation of straight chain fatty acids and a more recently identified pathway that degrades branched chain fatty acids and bile acid intermediates. Multifunctional protein-2 (MFP-2), also called d-bifunctional protein, catalyzes the second (hydration) and third (dehydrogenation) reactions of the latter pathway. In order to further clarify the physiological role of this enzyme in the degradation of fatty carboxylates, MFP-2 knockout mice were generated. MFP-2 deficiency caused a severe growth retardation during the first weeks of life, resulting in the premature death of one-third of the MFP-2(-/-) mice. Furthermore, MFP-2-deficient mice accumulated VLCFA in brain and liver phospholipids, immature C(27) bile acids in bile, and, after supplementation with phytol, pristanic and phytanic acid in liver triacylglycerols. These changes correlated with a severe impairment of peroxisomal beta-oxidation of very long straight chain fatty acids (C(24)), 2-methyl-branched chain fatty acids, and the bile acid intermediate trihydroxycoprostanic acid in fibroblast cultures or liver homogenates derived from the MFP-2 knockout mice. In contrast, peroxisomal beta-oxidation of long straight chain fatty acids (C(16)) was enhanced in liver tissue from MFP-2(-/-) mice, due to the up-regulation of the enzymes of the classical peroxisomal beta-oxidation pathway. The present data indicate that MFP-2 is not only essential for the degradation of 2-methyl-branched fatty acids and the bile acid intermediates di- and trihydroxycoprostanic acid but also for the breakdown of very long chain fatty acids.

Disruption of a yeast very-long-chain acyl-CoA synthetase gene simulates the cellular phenotype of X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is characterized biochemically by elevated levels of saturated very long-chain fatty acids (VLCFAs) in plasma and tissues. In X-ALD, peroxisomal very-long-chain acyl-CoA synthetase (VLCS) fails to activate VLCFAs, preventing their degradation via beta-oxidation. However, the product of the defective XALD gene (ALDP) is not a VLCS, but rather a peroxisomal membrane protein (PMP). Disruption of either or both of two yeast PMP genes related to the XALD gene did not produce a biochemical phenotype resembling that found in X-ALD fibroblasts. The authors identified a candidate yeast VLCS gene (the FAT1 locus) by its homology to rat liver VLCS. Disruption of this gene decreased VLCS activity, but had no effect on long-chain acyl-CoA synthetase activity. In FAT1-disruption strains, VLCS activity was reduced to 30-40% of wild-type in both a microsome-rich 27,000 g supernatant fraction and a peroxisome- and mitochondria-rich pellet fraction of yeast spheroplast homogenates. Separation of the latter organelles by density gradient centrifugation revealed that VLCS activity was peroxisomal and not mitochondrial. VLCS gene-disruption strains had increased cellular VLCFA levels, compared to wild-type yeast. The extent of both the decrease in peroxisomal VLCS activity and the VLCFA accumulation in this yeast model resembles that observed in cells from X-ALD patients. Characterization of the gene(s) responsible for the residual peroxisomal VLCS activity may suggest new therapeutic approaches in X-ALD.

Neonatal cholestasis: A new presentation of X-linked adrenoleukodystrophy

A French-Canadian boy presented with neonatal cholestasis and failure to thrive, bilateral polar cataracts, anemia, thrombocytopenia and hypolonia. Bom at 37 weeks gestational age, he weighed 2450 g (10%ile), with length 46 cm (10%ile) and head circumference 33 cm (50%ile). Jaundice was present at birth. No dysmorphism was noted Transaminases were consistently elevated >2-fold. Liver biopsy showed cholestasis and confirmed the presence of calalase-posilive structures, with normal peroxisomes and mitochondria. HIDA scintigraphy showed mild hepatocellular dysfunction. Other investigations including endoscopy, plasma and urine amino acids, serum copper, alpha-1-antitrypsin levels, erythrocyte galactose-1-phosphate levels, karyotype (46, XY) and TORCH viral studies were non-diagnostic. Brainstem auditory evoked potentials showed mild peripheral hearing loss at 3 weeks of age, and a central loss when repeated at 8 months of age. He developed cachexia, progressive hepatomegaly, splenomegaly, osteopenia, bruxism and opisthotonic posturing, with a progressive motor delay. CT scan revealed cortical atrophy. He died of liver failure at age 12 months after frequent episodes of gastrointestinal bleeding and continued neurological deterioration. Post-mortem, plasma very long-chain fatty acids (VLCFAs) results became available, showing elevation of the C26:C22 ratio. Phytanic acid, assayed on three stored samples was normal in two and 3-fold elevated in one. Other peroxisomal function tests including plasma pipecolic acid and rbc plasmalogen ratios were normal, but C18 DMA levels were somewhat lower than normal. Fibroblast C26:0 and C22 levels were elevated 5-fold, and the C26/C22 ratio, 9-fold. Oxidation of C24:0 was 20% of control values. On immunostaining with antibody to the ALD protein, fibroblasts were CRIM negative. The ALD protein gene contained a previously-unreported mutation, a thymine-to-cytosine transition at nucleotide 1654 in exon 7, predicted to change Ser 552 to Pro in the ATP binding domain. Although the patient's mother had normal plasma VLCFA levels, a subsequent pregnancy showed an elevated C26/C22 ratio in amniocytes and was terminated. A similar patient with biochemically-proven ALD and rapidly-progressive cholestasis was recently reported (Corzo. D. et al., Am J Hum Genet 65, 4 (Suppl.): A1295) demonstrating that the association of mutations in the ALD protein gene and neonatal cholestasis is not spurious, and expanding the phenotypic spectrum of ALD to include neonatal cholestatic jaundice with liver failure.

Very long-chain fatty acids in Rett syndrome.

Rett syndrome (RS), found exclusively in girls, is characterised by a global deceleration of psychomotor development, loss of acquired speech, loss of manual skills and subsequent deceleration of head growth. The cause of this syndrome is so far unknown. To date there are no biological markers for RS; clinical diagnostic criteria were proposed by the Rett Syndrome Diagnostic Criteria Work Group 1988. The first objective of this study was to assay the levels of very long-chain fatty acids (VLCFA), i.e. C22:0, C24:0, C26:0, by gas chromatography in sera of 30 girls with RS. The VLCFA levels in the studied group were lower than the reference range for healthy children and control group. VLCFA levels were again measured after 2 months of L-carnitine administration in the same groups. VLCFA levels had increased. It is possible that the low VLCFA levels have some relation to the lowered carnitine levels. It may be that low carnitine levels impede transportation to mitochondria, thus the oxidation of long-chain fatty acids is inhibited, and compensated to a certain extent by intensified beta-oxidation of VLCFA in the peroxisomal system. Raising carnitine levels could improve substrate delivery for mitochondrial beta-oxidation of long-chain fatty acids, thus reducing the use of VLCFA as substrates for beta-oxidation. We consider VLCFA to be secondary to the pathogenesis of RS, but the possible abnormalities in their levels may provide an insight into the development of this disease. Very long-chain fatty acid and carnitine levels are decreased in Rett syndrome L-Carnitine administration increased very long-chain fatty acid levels in serum.

Plasma very long chain fatty acids in 3,000 peroxisome disease patients and 29,000 controls.

The assay of plasma very long chain fatty acids (VLCFAs), developed in our laboratory in 1981, has become the most widely used procedure for the diagnosis of X-linked adrenoleukodystrophy (X-ALD) and other peroxisomal disorders. We present here our 17 years' experience with this assay. Three VLCFA parameters, the level of hexacosanoic acid (C26:0), the ratio of C26:0 to tetracosanoic acid (C24:0), and of C26:0 to docosanoic acid (C22:0), were measured in 1,097 males (hemizygotes) with X-ALD, 1,282 women heterozygous for this disorder, including 379 obligate heterozygotes, 797 patients with other peroxisomal disorders, and 29,600 control subjects. All X-ALD hemizygotes who had not previously received Lorenzo's oil or a diet with a high erucic acid content had increased VLCFA levels, but the application of a discriminant function based on all three measurements is required to avoid the serious consequences of a false-negative result. VLCFA levels are increased at day of birth, thus providing the potential for neonatal mass screening, are identical in the childhood and adult forms, and do not change with age. Eighty-five percent of obligate heterozygotes had abnormally high VLCFA levels, but a normal result does not exclude carrier status. VLCFA levels were increased in all patients homozygous for Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum's disease, and in patients with deficiencies of peroxisomal acyl-coenzyme A oxidase, bifunctional enzyme, and 3-oxoacyl-coenzyme A thiolase. In these patients the degree of VLCFA excess correlated with clinical severity.

Etiological diagnosis of primary adrenal insufficiency using an original flowchart of immune and biochemical markers.

Approximately 70-80% of cases of primary adrenal insufficiency are classified as idiopathic. An effective protocol for the etiological diagnosis of primary adrenal insufficiency is needed to ensure correct patient management. With the aim of developing an algorithm for the etiological diagnosis of primary adrenal insufficiency, we studied 56 Italian patients with nonsurgical primary adrenal insufficiency and 24 French patients with X-linked adrenoleukodystrophy (ALD) for serum levels of adrenal cortex, steroid-21-hydroxylase (21OHAb), islet cell (ICA), glutamate decarboxylase (GAD65Ab), IA2/ICA512 (ICA512Ab), thyroid peroxidase (TPOAb) autoantibodies, and plasmatic concentrations of very long chain fatty acids (VLCFA). High levels of 21OH and adrenal cortex antibodies were found in 35/42 (83%) and 17/42 (40%) Italian patients with idiopathic adrenal insufficiency, respectively. Levels of adrenal autoantibodies correlated inversely with disease duration (P < 0.0001). Elevated VLCFA were found in 4/42 (10%) idiopathic patients. A total of 34/35 (97%) idiopathic patients with a disease duration of less than 20 yr was positive for either 21OHSAb or elevated levels of VLCFA. None of 14 patients with posttuberculosis adrenal insufficiency had elevated levels of either adrenal antibodies or VLCFA. ICA, GAD65Ab, ICA512Ab, and TPOAb were found in 6/56 (11%), 8/56 (14%), 4/56 (7%), and 23/56 (41%) patients, respectively. None of 24 French ALD patients with adrenal insufficiency was positive for organ-specific autoantibodies. The measuring of 21OH antibodies and plasma VLCFA levels enabled a correct diagnosis of autoimmune (89%) and ALD (8%) in 97% of patients with idiopathic primary adrenal insufficiency of less than 20 yr of duration. The results of our study have important therapeutic and prognostic implications.

Cytokine-induced accumulation of very long-chain fatty acids in rat C6 glial cells: implication for X-adrenoleukodystrophy.

X-Adrenoleukodystrophy (X-ALD) is an inherited metabolic disorder of very long-chain fatty acids (VLCFA) with subsequent manifestation of neuroinflammatory disease. To investigate the possible role of proinflammatory cytokines in the X-ALD disease process, we examined the effect of cytokines on the metabolism of VLCFA in C6 glial cells expressing oligodendrocyte-like properties. C6 glial cells under serum-free conditions were treated with different combinations of cytokines (tumor necrosis factor-alpha, interleukin-1beta, interferon-gamma) or cytokine with bacterial lipopolysaccharide (LPS). Cytokine-treated C6 cells had higher concentrations of VLCFA, measured as percent weight and also as C26:0/C22:0 ratio, which were 300-400% as compared with the controls. We also found increased levels of C26:1 in cytokine-treated cells. The accumulation of VLCFA paralleled the decrease (35-55%) in peroxisomal beta-oxidation activity and a 12- to 14-fold increase in the production of nitric oxide (NO). Individual cytokines were unable either to produce NO or to increase the levels of VLCFA in C6 cells. Inhibition of cytokine-induced NO production by L-N-methylarginine, an inhibitor of NO synthase (NOS), and N-acetylcysteine, an inhibitor of cytokine-mediated induction of inducible NOS, normalized the peroxisomal beta-oxidation activity and the levels of VLCFA, suggesting a role for the proinflammatory cytokines and NO toxicity in the neuropathological changes associated with abnormal VLCFA metabolism (e.g., X-ALD). X-ALD is a peroxisomal disease having deficient oxidation of VLCFA, resulting in the excessive accumulation of VLCFA in all tissues but especially in brain. We observed greater increase in levels of VLCFA in the inflammatory region of ALD brain (in the demyelinating plaque and the area around the plaque) than in the normal-looking area away from the plaque; this also indicates that cytokines in the proinflammatory region may augment the VLCFA defect caused by the inherited abnormality in X-ALD brain. Although C6 glial cultured cells do not reflect the X-ALD model precisely, the observed relationship between the cytokine-induced inhibition of the oxidation of VLCFA, excessive accumulation of VLCFA, and excessive production of NO and their normalization by inhibitors of NOS in C6 glial cells suggests that NO-mediated toxicity may play a role in VLCFA-associated neuroinflammatory diseases (e.g., X-ALD).

Lovastatin and sodium phenylacetate normalize the levels of very long chain fatty acids in skin fibroblasts of X- adrenoleukodystrophy

The present study underlines the importance of lovastatin, an inhibitor of 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase, and the sodium salt of phenylacetic acid (NaPA), an inhibitor of mevalonate pyrophosphate decarboxylase, in normalizing the pathognomonic accumulation of saturated very long chain fatty acids (VLCFA) in cultured skin fibroblasts of X-adrenoleukodystrophy (X-ALD) in which the ALD gene is either mutated or deleted. Lovastatin or NaPA alone or in combination stimulated the β-oxidation of lignoceric acid (C 24:0) and normalized the elevated levels of VLCFA in skin fibroblasts of X-ALD. Ability of lovastatin and NaPA to normalize the pathognomonic accumulation of VLCFA in skin fibroblasts of X-ALD may identify these drugs as possible therapeutics for X-ALD.

A mouse model for X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (X-ALD) is a peroxisomal disorder with impaired beta-oxidation of very long chain fatty acids (VLCFAs) and reduced function of peroxisomal very long chain fatty acyl-CoA synthetase (VLCS) that leads to severe and progressive neurological disability. The X-ALD gene, identified by positional cloning, encodes a peroxisomal membrane protein (adrenoleukodystrophy protein; ALDP) that belongs to the ATP binding cassette transporter protein superfamily. Mutational analyses and functional studies of the X-ALD gene confirm that it and not VLCS is the gene responsible for X-ALD. Its role in the beta-oxidation of VLCFAs and its effect on the function of VLCS are unclear. The complex pathology of X-ALD and the extreme variability of its clinical phenotypes are also unexplained. To facilitate understanding of X-ALD pathophysiology, we developed an X-ALD mouse model by gene targeting. The X-ALD mouse exhibits reduced beta-oxidation of VLCFAs, resulting in significantly elevated levels of saturated VLCFAs in total lipids from all tissues measured and in cholesterol esters from adrenal glands. Lipid cleft inclusions were observed in adrenocortical cells of X-ALD mice under the electron microscope. No neurological involvement has been detected in X-ALD mice up to 6 months. We conclude that X-ALD mice exhibit biochemical defects equivalent to those found in human X-ALD and thus provide an experimental system for testing therapeutic intervention.

Exogenous lipids in myelination and myelination.

Myelinogenesis is a scheduled process that depends on both the intrinsic properties of the cell and extracellular signals. In rat brain, myelin development is an essentially postnatal event and environmental interferences could affect myelin synthesis. Nutrition plays an important role, since severe postnatal malnutrition and essential fatty acid (EFA) deficiency cause hypomyelination. Even though the dietary effects are more pronounced in the postnatal period, dietary lipids can affects myelin development also in the postweaning period. Rats fed with diets rich in polyunsaturated n3 fatty acids showed a decrease of the relative amount of myelin basic protein (MBP) and a CNPase activity indicating a delay in myelin deposition and/or an instability of its structure. Our recent studies have shown that dietary fatty acids can be positively involved in the control of central nervous system (CNS) myelinogenesis. Offspring of rats fed diets containing odd chain fatty acid during pregnancy and lactation show an early development of behavioral reflexes linked to myelination compared to controls fed a diet containing margarine. Subsequent studies have shown that the expression of myelin proteins is higher in test than in control animals, but the mechanism of the action of fatty acids is still unknown. Also human brain myelinogenesis can be affected by environmental factors. EFA deficiency has been well studied for the important role of C22:6 (a C18:3 metabolite) in the vision system development. The observation that dietary fatty acids can affect membrane composition has led to the use of modified diets in some CNS pathological conditions. For example, preterm infants characterized by low levels of C22:6 and fed with formulae diets enriched in this fatty acid, show a recovery of visual function. The administration of C22:6 has also been tested in patients affected by peroxisomal biogenesis disorders which are associated with very low levels of this fatty acid in the brain. During the treatment, C22:6 content increases in red blood cells, and probably in the brain membranes, as considerable neurologic and electrophysiological improvement suggest. A mixture of glyceryltrierucate and glyceryltrioleate has been tested in the demyelinating disease Adrenoleukodistrophy which is characterized by an abnormal accumulation of very long chain fatty acids (VLCFA) in tissues and fluids. The diet is able to lower VLCFA levels in plasma, but its efficacy for myelin damage is debated. Lastly, a diet which reduces the intake of saturated fatty acid and increases the quantity of polyunsaturates is suggested for multiple sclerosis patients since a decrease of linoleic acid in their plasma and erythrocytes has been observed. Such a diet seems able to reduce the severity of the attacks.

Oxidation of pristanic acid in fibroblasts and its application to the diagnosis of peroxisomal beta-oxidation defects.

Pristanic acid oxidation measurements proved a reliable tool for assessing complementation in fused heterokaryons from patients with peroxisomal biogenesis defects. We, therefore, used this method to determine the complementation groups of patients with isolated defects in peroxisomal beta-oxidation. The rate of oxidation of pristanic acid was reduced in affected cell lines from all of the families with inherited defects in peroxisomal beta-oxidation, thus excluding the possibility of a defective acyl CoA oxidase. Complementation analyses indicated that all of the patients belonged to the same complementation group, which corresponded to cell lines with bifunctional protein defects. Phytanic acid oxidation was reduced in fibroblasts from some, but not all, of the patients. Plasma samples were still available from six of the patients. The ratio of pristanic acid to phytanic acid was elevated in all of these samples, as were the levels of saturated very long chain fatty acids (VLCFA). However, the levels of bile acid intermediates, polyenoic VLCFA, and docosahexaenoic acid were abnormal in only some of the samples. Pristanic acid oxidation measurements were helpful in a prenatal assessment for one of the families where previous experience had shown that cellular VLCFA levels were not consistently elevated in affected individuals.

Distinction between peroxisomal bifunctional enzyme and acyl‐CoA oxidase deficiencies

The clinical distinction between patients with a disorder of peroxisome assembly (e.g., Zellweger syndrome) and those with a defect in a peroxisomal fatty acid beta-oxidation enzyme can be difficult. We studied 29 patients suspected of belonging to the latter group. Using complementation analysis, 24 were found to be deficient in enoylcoenzyme A hydratase/3-hydroxyacylcoenzyme A dehydrogenase bifunctional enzyme and 5 were deficient in acyl-CoA oxidase. Elevated plasma very long-chain fatty acids (VLCFA), impaired fibroblast VLCFA beta-oxidation, decreased fibroblast phytanic acid oxidation, normal plasmalogen synthesis, normal plasma L-pipecolic acid level, and normal subcellular catalase distribution were characteristic findings in both disorders. The elevation in plasma VLCFA levels and impairment in fibroblast VLCFA beta-oxidation were more severe in bifunctional-deficient than in oxidase-deficient patients. The clinical course in bifunctional deficiency (profound hypotonia, neonatal seizures, dysmorphic features, age at death approximately 9 months) was more severe than in oxidase deficiency (moderate hypotonia without dysmorphic features, development of a leukodystrophy, age at death approximately 4 yr). Based on these findings, accurate early diagnosis of these deficiencies of peroxisomal beta-oxidation enzymes is possible.

X‐linked adrenoleukodystrophy presenting as neurologically pure familial spastic paraparesis

The familial spastic paraplegias (FSPs) are heterogeneous neurologic disorders that are known to occur clinically as "pure" or "complicated" forms. Although some of the complicated FSPs have been linked to specific metabolic defects, the pure forms of this disorder remain idiopathic and are considered to be primary system degenerations. We report the case of a 28-year-old man who has evidenced a neurologically pure spastic paraparesis since age twenty-five. Consistent with this diagnosis were the findings of magnetic resonance imaging, which revealed atrophy of the thoracic spinal cord without evidence for white matter disease in the cerebrum, cerebellum, or brainstem. His 32-year-old brother has also evidenced progressive spastic paraparesis since age 30, but his case is confounded by a severe head injury at age 24 that caused a skull fracture and a focal demyelinating lesion of the right frontal lobe. Both patients have had hypogonadism, requiring treatment with testosterone, since age 20. Measurement of plasma levels of very long-chain fatty acids (VLCFA) revealed that both brothers had concentrations diagnostic of adrenoleukodystrophy; their mother had plasma VLCFA levels in the heterozygous range. We conclude that neurologically pure FSP can be an early manifestation of adrenoleukodystrophy and that levels of plasma VLCFA should be determined for all cases of FSP in which X-linked inheritance appears tenable. These considerations may have bearing on the ongoing linkage studies for these disorders.

High dose immunoglobulin IV treatment in adrenoleukodystrophy.

X-linked adrenoleukodystrophy (ALD) is an inborn error of peroxisomal metabolism characterised by progressive demyelination of the central nervous system and by hypoadrenalism. The biochemical defect of ALD results in an impairment in degradation of very long chain fatty acids (VLCFA) with their accumulation in plasma and tissues. Many therapeutic approaches have been tried. Recently, a restricted diet and glycerol trioleate/erucic (GTOE) supplementation have shown normalisation of VLCFA plasma levels, although they are not effective in altering the clinical course of X-linked ALD. The preliminary results are presented of a twelve month trial of immunomodulation by intravenous high-dose immunoglobulins in six patients, mean (SD) age 10.48 (2.8) affected by X-linked ALD, on VLCFA restricted diet plus GTOE supplementation therapy. Six patients aged 9.30 (1.5) with similar clinical characteristics and on the same restricted VLCFA regime of GTO/GTE therapy were studied as the control group. After two months VLCFA levels fell to normal values and remained so for all patients throughout the study. These data show that immunoglobulins are not able to arrest the progression of the disease. The MRI and clinical symptoms deteriorated to the same extent in both groups.

X-LINKED ADRENOLEUKODYSTROPHY (ALD): HORMONAL AND CLINICAL FINDINGS DURING DIETARY ERUCIC-TRIOLEATE THERAPY

X-linked ALD is characterized by primary adrenal insufficiency, demyelination and accumulation of very long chain fatty acids (VLCFA). VLCFA have a toxic effect on adrenocortical cell by increasing cell membrane microviccosity, leading to decreased ability to respond to ACTH (Whitcomb RW et al. J Clin invest 81:185·188, 1988). The regimen of VLCFA restricted diet supplemented with a mixture of oleic and erucic acid (GTEO) determined, for the first time, a normalisation of plasma VLCFA levels in ALD patients. Thus the data suggest that the pathological changes affecting the nervous and endocrine system may be delayed, or even arrested, in these patients. We now report the effects on the clinical course of ALD of this therapeutic approach in 18 patients treated with dietary-GTOE supplementation up to 5 years. There was no effect on the clinical course in patients with childhood and adolescent ALD assessed by neurological, neuropsycological, and neuroadiological (NMI) evaluations. Patients with adrenomyeloneropathy and presymptomic did not exhibit progression of the disease. All but 3 patients had hyposdrenalism. Plasma eldosterone levels were reduced and PRA was increased. Interestingly, normalisation of VLCFA levels in these patients resulted in an increase of aldosterone (M±SD: 112.3±94.6 vs 379.2±12.1 pg/ml, p<0.05) and a reduction of PRA levels form 10.2±7.6 to 5.1±2.8 ng/ml/h, confirming that VLCFA excess has a direct toxic effect on the adrenals whereas other factors are more likely involved in the determination of the pathological changes in the nervous system.

X-linked adrenoleukodystrophy and haemophilia A in the same kindred.

Journal of Inherited Metabolic DiseaseVolume 16, Issue 3 p. 595-598 Short Communication X-linked adrenoleukodystrophy and haemophilia A in the same kindred A. Nogueira, A. Nogueira Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorP. Jorge, P. Jorge Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorJ. Dores, J. Dores Departamentos de Endocrinologia, Porto, PortugalSearch for more papers by this authorM. Cunha, M. Cunha Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorS. Sousa, S. Sousa Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorI. Pereira, I. Pereira Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorM. Campos, M. Campos Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorB. Justica, B. Justica Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorD. Quelhas, D. Quelhas Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorM. Sá Miranda, M. Sá Miranda Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this author A. Nogueira, A. Nogueira Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorP. Jorge, P. Jorge Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorJ. Dores, J. Dores Departamentos de Endocrinologia, Porto, PortugalSearch for more papers by this authorM. Cunha, M. Cunha Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorS. Sousa, S. Sousa Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorI. Pereira, I. Pereira Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorM. Campos, M. Campos Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorB. Justica, B. Justica Hematologia do Hospital Geral de Sto António, Porto, PortugalSearch for more papers by this authorD. Quelhas, D. Quelhas Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this authorM. Sá Miranda, M. Sá Miranda Departamento de Enzimologia do Instituto de Genética Médica, Praça Pedro Nunes 74, Porto, 4000 PortugalSearch for more papers by this author First published: 01 May 1993 https://doi.org/10.1007/BF00711691Citations: 2AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume16, Issue3May 1993Pages 595-598 RelatedInformation

Prenatal diagnosis in high risk pregnancies for Zellweger syndrome.

Zellweger syndrome is a lethal disorder. At present, no effective therapies are known for the patients of Zellweger syndrome. Recently a typical case of Zellweger syndrome in Japan was observed. In spite of intensive care, the patient died at the age of 3 months. Following this, the parents requested prenatal diagnosis for their following two pregnancies. We investigated levels of very long chain fatty acids (VLCFA), levels of bile acids in amniotic fluid and immunoblotting of peroxisomal beta-oxidation enzymes in cultured amniocytes. We report that immunoblotting using cultured amniocytes is an effective method for prenatal diagnosis of Zellweger syndrome. Furthermore, if we use immunoblotting for prenatal diagnosis, we can discriminate pseudoZellweger syndrome from pseudoneonatal adrenoleucodystrophy. Following prenatal diagnosis, two healthy babies were delivered. After birth, no abnormal levels of VLCFA in either serum or red blood cell membranes were confirmed. In this paper, we report that we can diagnose a healthy fetus in a high risk pregnancy for Zellweger syndrome.

Characterization of X-linked adrenoleukodystrophy in different biological specimens from ten Portuguese families.

X-linked adrenoleukodystrophy (ALD) is a severe neurodegenerative disease characterized by progressive demyelination, adrenocortical insufficiency and accumulation in tissues and body fluids of unbranched, saturated very long-chain fatty acids (VLCFA). The diagnosis of ALD is usually based on clinical history, neurological examination and the determination of levels of VLCFA in plasma and cultured skin fibroblasts. In the present paper we report the biochemical findings in plasma, cultured skin fibroblasts and lymphoblastoid cell lines from ALD patients. The results obtained indicate that the increment of the ratios C24:0 to C22:0 and C26:0 to C22:0 and of the concentration C26:0 (micrograms/ml) in plasma was parallel with that of fibroblasts, but not with that of Epstein-Barr virus (EBV)-transformed lymphocytes, suggesting that this cell line is not reliable for diagnosis of ALD by VLCFA analysis. Subsequent studies carried out on family members revealed heterozygotes other than obligate carriers and hemizygotes who were pre-symptomatic or had a misdiagnosis of multiple sclerosis or psychosis.

Adrenoleucodystrophy: a molecular genetic study in five families.

A genetic study has been performed on five adrenoleucodystrophy families using DNA probes from Xq28. Members of each family had previously been tested for carrier status using the biochemical assay for very long chain fatty acids (VLCFAs), but several persons at risk had equivocal results. DNA analysis with four DNA probes St14-1 (DXS52), DX13 (DXS15), MN12 (DXS33), and hs7 showed no crossovers between them and the disease locus in persons who were clinically affected or had high levels of VLCFA or both. Thus, the genotypes provided by the DNA probes could be used for accurate carrier detection and prenatal diagnosis could be offered. Of the 17 at risk females with VLCFA levels in the normal (1 SD) range, five were defined as carriers and 12 were considered not to be.

Two Siblings with Phenotypes Mimicking Peroxisomal Disorders but with Discordant Biochemical Findings

The authors present a report on two sibling with a nearly identical phenotype mimicking peroxisomal disorder but with totally discordant biochemical findings. In an attempt to confirm the diagnosis of a peroxisomal disorder, plasma levels of very long chain fatty acids (VLCFA) and phytanic acid were determined. In addition, fibroblasts profile of VLCFA and plasmalogen levels were evaluated for Case 2. Pathomorphological examinations represented by lymph node and kidney biopsies as well as postmortem examinations of liver, adrenals and brain were performed in Case 1. The phenotypes of both siblings showed marked resemblance to those observed in children with Zellweger syndrome. The results of biochemical tests performed in Case 1, together with abundant peroxisomes in the liver and the wide spectrum of clinical abnormalities suggest pseudo-Zellweger or Zellweger-like syndromes, but no conclusive data have been found. The plasmalogen level in fibroblasts as well as the fibroblasts profile of VLCFA noted in Case 2 were within the normal range, thus excluding the possibility of a peroxisomal disorder. The striking phenotype resemblance of the siblings mimicking Zellweger, together with discordant biochemical findings, are difficult to explain on the basis of currently available tests.