Adrenomyeloneuropathy: a probable variant of adrenoleukodystrophy. I. Clinical and endocrinologic aspects

A two-year trial of oleic and erucic acids ("Lorenzo's oil") as treatment for adrenomyeloneuropathy

BACKGROUND

Adrenomyeloneuropathy is an X-linked recessive disorder characterized by myelopathy, peripheral neuropathy, and cerebral demyelination, which develop in association with the accumulation of very-long-chain fatty acids. The administration of oleic and erucic acids inhibits the synthesis of very-long-chain fatty acids. Recently such dietary treatment has been widely publicized as a possible cure for this disease.

METHODS

We conducted an open trial in 14 men with adrenomyeloneuropathy, 5 symptomatic heterozygous women, and 5 boys (mean age, 13 years) with preclinical adrenomyeloneuropathy. The patients ate a low-fat diet and received daily doses of glycerol trioleate oil (1.7 g per kilogram of body weight) and glycerol trierucate oil (0.3 g per kilogram). Clinical manifestations, cerebral and spinal cord magnetic resonance imaging (MRI) scans, nerve conduction, and brain-stem auditory and somatosensory evoked potentials were studied prospectively over 18 to 48 months. Plasma levels of very-long-chain fatty acids and the side effects of erucic acid were monitored monthly.

RESULTS

By week 10, plasma very-long-chain fatty acid levels declined nearly to normal. Nonetheless, over a mean follow-up of 33 months none of the 14 men with adrenomyeloneuropathy improved. In nine men there was functional deterioration, coincident in four with new cerebral lesions on MRI. In a single patient there was a reduction in cerebellar demyelination, but without clinical improvement. In one of the five asymptomatic boys signs of myelopathy developed. There were no changes in the symptomatic heterozygous women. There was some improvement in peroneal-nerve conduction, but no detectable clinical improvement. Conduction to the parietal cortex (T12-P37 interpeak latency) worsened in both the symptomatic men and the boys with preclinical adrenomyeloneuropathy. There was no change in other somatosensory evoked potentials or in brain-stem auditory evoked potentials. Asymptomatic thrombocytopenia (< 100,000 cells per cubic millimeter) was noted in six patients.

CONCLUSIONS

In this open trial we found no evidence of a clinically relevant benefit from dietary treatment with oleic and erucic acids ("Lorenzo's oil") in patients with adrenomyeloneuropathy.

Adrenoleukomyeloneuropathy presenting as cerebellar ataxia in a young child: a probable variant of adrenoleukodystrophy

A child aged 5 years 7 months was diagnosed as suffering from adrenoleukomyeloneuropathy (ALMN). The first sign was ataxia, and high intensity lesions were observed in the cerebellar hemispheres on T2-weighted brain MRI. His condition progressed rapidly to a vegetative state in 1 year. When aged 7 years 3 months adrenal insufficiency supervened and his skin turned dark. Rectal biopsy revealed linear cytoplasmic inclusions in macrophages in the rectal membrane. At the age of 8 years 2 months, an analysis of very long-chain fatty acids of sphingomycin in plasma led to the final diagnosis. At the age of 10 years, cerebellar and cerebral atrophy were prominent and diffuse high intensity lesions were noted in the cerebellum and cerebrum. An onset below 9 years of age has not previously been documented in ALMN.

Visual evoked potentials in adrenoleukodystrophy: a trial with glycerol trioleate and Lorenzo oil

Adrenoleukodystrophy is an X-linked metabolic disorder with very-long-chain fatty acid (VLCFA) accumulation and multifocal nervous system demyelination, often with early involvement of visual pathways. Dietary therapy with glycerol trioleate and glycerol trierucate (Lorenzo oil) diminishes VLCFA levels. In a study of patients with the adrenomyeloneuropathy phenotype of adrenoleukodystrophy, we used pattern-reversal visual evoked potentials to evaluate visual pathways before and after treatment. Of 108 patients tested, all 26 women and 68 of the 82 men had normal potentials at baseline. Seventy patients were retested at 1 year, at which time VLCFA levels were markedly diminished. Of them, the responses in the 10 men who showed abnormalities at baseline remained abnormal; the latencies in 4 men with initially normal responses became abnormal. No patients improved. There were no correlations between disease duration prior to treatment, baseline P100 latencies, VLCFA levels, or the change in P100 latencies and VLCFA levels after dietary treatment for 1 year. Pattern-reversal visual evoked potentials were abnormal in 17% of the men with adrenoleukodystrophy, and there was no evidence that reduction of VLCFA levels improved or retarded visual pathway demyelination.

Delay in diagnosis of X-linked adrenoleukodystrophy

In 16 consecutive patients with clinically suspected and biochemically proven X-linked adrenoleukodystrophy (X-ALD), total delay (interval between onset of symptoms and diagnosis) and specialist delay (interval between referral to a specialist and diagnosis) were determined. All patients previously were unaware of the existence of X-ALD in their families. From the time of onset of symptoms attributable to this disease until diagnosis, mean total delay was 9.9 (range 1-33) years and mean specialist delay was 8.4 (range 0-33) years. Three patients who presented with adrenocortical insufficiency had mean total and specialist delays of 17.3 (range 9-33) years. Five patients with an initial diagnosis of multiple sclerosis had mean total and specialist delays of 12.8 (range 5-25) and 11.2 (range 1-23) years, respectively. In 12 patients with adrenomyeloneuropathy--the second most frequent phenotype of X-ALD--mean total delay was 11.0 (range 2-33) years and mean specialist delay 9.1 (range 0-33) years. Since 1981 X-ALD can be reliably diagnosed on the basis of elevated levels of very long chain fatty acids in plasma and/or cultured fibroblasts. The delays therefore must have been due to the unfamiliarity with the clinical manifestations and diagnostic possibilities of this disease. Once X-ALD is diagnosed, dietary treatment and/or bone marrow transplantation may be considered. Genetic counseling should be performed, and screening of other family members is essential for the early identification of affected relatives.

Sparse hair and multiple endocrine disorders in two women heterozygous for adrenoleukodystrophy

We describe two sisters (40 and 42 years old) heterozygous for adrenoleukodystrophy who have multiple endocrine disorders. In addition to the characteristic neurological symptoms, the younger patient has Addison disease and primary hypothyroidism attributable to autoimmune thyroiditis, and the older one has Graves disease. Both patients have loss of body hair and sparse scalp hair, which have not been reported previously in women heterozygous for adrenoleukodystrophy. After the institution of glucocorticoid replacement therapy, the younger sister, who has adrenal insufficiency, has shown unexpected neurological improvement.

Screening of patients with hereditary spastic paraparesis and Addison's disease for adrenoleukodystrophy/adrenomyeloneuropathy

X-linked adrenoleukodystrophy/adrenomyeloneuropathy presents a wide variation of clinical manifestations and may mimic several diseases. A screening investigation by measuring plasma saturated very long-chain fatty acids was performed in two groups of patients. Among six patients with hereditary spastic paraparesis one woman was detected to be a heterozygous gene carrier. However, in a group of eleven adult men with idiopathic Addison's disease the plasma concentrations of very long-chain fatty acids were all within normal limits. We conclude that X-linked adrenoleukodystrophy and symptomatic heterozygous females should be considered in cases of progressive spastic paraparesis.

Adrenoleukodystrophy: phenotypic variability and implications for therapy

X-linked adrenoleukodystrophy (ALD) is a relatively common disorder that shows a great deal of phenotypic variability. Approximately half of the patients have the rapidly progressive childhood cerebral form that is associated with an inflammatory response in brain and leads to total disability or death during the first decade. Twenty five per cent or more of the patients have adrenomyeloneuropathy (AMN), a form that progresses slowly, involves the spinal cord mainly, shows little or no inflammatory response, manifests in adulthood, and is compatible with a near-normal life span. The two forms of the disease occur frequently within the same kindreds and nuclear families. Segregation analysis based on 3862 individuals in 89 kindreds points to the existence of an autosomal modifier locus with a likelihood ratio of 20:1. In addition, we present preliminary results of three types of therapy. Two hundred and four patients have received a dietary regimen that combines the administration of oils containing mono-unsaturated fatty acids (oleic and erucic) with the restricted intake of very long-chain fatty acids. This regimen normalizes the levels of satured very long-chain fatty acids in plasma within 4 weeks. It appears to improve peripheral nerve function in patients with AMN, and a large-scale trial is in progress to determine whether it can prevent the onset of neurological involvement in patients who have the biochemical abnormality of ALD but are neurologically intact. We report early results of bone marrow transplantation in 14 patients. There is encouraging but still preliminary evidence that transplantation can arrest the progression of the disease in patients with mild neurological involvement. There is urgent need to develop methods to combat the rapid progression of the cerebral forms of the disease, which so far has resisted therapeutic intervention, including immunosuppression or the administration of immunoglobulin.

Adrenomyeloneuropathy--report on a family

A family is reported in which there is one case of adrenomyeloneuropathy, one case of Addison's disease and at least three heterozygous females with spastic paraparesis and peripheral neuropathy. Adrenomyeloneuropathy has not been reported previously in Scandinavia. The differences in the clinical picture between the sexes and at different ages are emphasized. Elevation of the levels of very-long-chain fatty acids in plasma is a characteristic feature of the disease and confirms the diagnosis. Some recent reports in the literature seem to provide some hope that the clinical manifestations of adrenomyeloneuropathy/adrenoleukodystrophy may be prevented.

Effect of ciprofibrate on the activation and oxidation of very long chain fatty acids

The effect of ciprofibrate, a hypolipidemic drug, was examined in the metabolism of palmitic (C16:0) and lignoceric (C24:0) acids in rat liver. Ciprofibrate is a peroxisomal proliferating drug which increases the number of peroxisomes. The palmitoyl-CoA ligase activity in peroxisomes, mitochondria and microsomes from ciprofibrate treated liver was 3.2, 1.9 and 1.5-fold higher respectively and the activity for oxidation of palmitic acid in peroxisomes and mitochondria was 8.5 and 2.3-fold higher respectively. Similarly, ciprofibrate had a higher effect on the metabolism of lignoceric acid. Treatment with ciprofibrate increased lignoceroyl-CoA ligase activity in peroxisomes, mitochondria and microsomes by 5.3, 3.3 and 2.3-fold respectively and that of oxidation of lignoceric acid was increased in peroxisomes and mitochondria by 13.4 and 2.3-fold respectively. The peroxisomal rates of oxidation of palmitic acid (8.5-fold) and lignoceric acid (13.4-fold) were increased to a different degree by ciprofibrate treatment. This differential effect of ciprofibrate suggests that different enzymes may be responsible for the oxidation of fatty acids of different chain length, at least at one or more step(s) of the peroxisomal fatty acid beta-oxidation pathway.

MR imaging of adrenoleukodystrophy

We performed MRI in 7 cases with adrenoleukodystrophy (ALD), including 3 cases with childhood ALD, 3 cases with adrenomyeloneuropathy (AMN) and one symptomatic heterozygote. The symptomatic heterozygote was the mother of the patient with AMN. High-field-strength (2.0T) MRI was used in two cases with childhood ALD. In all 3 cases of childhood ALD, MR showed widespread lesions in both cerebral hemispheres. Areas of low intensity in the diencephalon or striatum on heavily T2-weighted images at 2.0T were seen in 2 cases with childhood ALD. Cerebral lesions confined to the internal capsule, cerebral peduncle and optic radiation in the adult onset ALD including AMN and symptomatic heterozygote, have not been reported and this confinement may indicate an early stage of the disease.

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.

Adrenomyeloneuropathy presenting as Addison's disease in childhood

Adrenoleukodystrophy, a sex-linked peroxisomal disorder that results in the impaired oxidation of long-chain saturated fatty acids and causes neurologic impairment, is a rare cause of Addison's disease in children. Adrenomyeloneuropathy is the name given to a biochemically identical but milder and more slowly progressive variant of adrenoleukodystrophy that affects young adults, in whom adrenal insufficiency may long precede nervous system dysfunction. The transmission of adrenomyeloneuropathy, like that of most cases of adrenoleukodystrophy, is sex-linked. Because of a preponderance of male patients among a group of patients with the onset of adrenal failure in childhood, we questioned whether this condition might be the initial manifestation of adrenomyeloneuropathy. We therefore measured the plasma concentrations of very-long-chain saturated fatty acids in eight patients with adrenal insufficiency; of these, five had elevated plasma hexacosanoic acid concentrations (range, 2.42 to 6.43 mumol per liter; mean normal level [+/- SD], 0.83 +/- 0.45), confirming the presence of adrenomyeloneuropathy. Magnetic resonance imaging showed clear evidence of brain involvement in all five patients. Reexploration of the family histories revealed additional missed cases. We conclude that the possibility of adrenomyeloneuropathy should be considered in any boy with Addison's disease.

Improved determination of very-long-chain fatty acids in plasma and cultured skin fibroblasts: applications to the diagnosis of peroxisomal disorders

Current techniques for the determination of very-long-chain fatty acids from biological samples require laborious procedures including solvent extraction of lipids, purification, hydrolysis, derivatization, purification of derivatized fatty acids by thin-layer chromatography and finally gas chromatographic analysis. A comparison was made between such a procedure based on solvent extraction and a method based on a recently developed direct one-step transesterification reaction. The latter method proved to be much faster and led to higher recoveries of all individual very-long-chain fatty acids from both plasma and skin fibroblasts. The assay proved to be very convenient in the diagnosis of genetically determined disorders in which very-long-chain fatty acids accumulate in tissues and body fluids. Because of its simplicity and speed and because it can be performed with as little as 100 microliters of plasma, the method can be recommended as a valuable screening procedure for peroxisomal disorders.

[Adrenoleukodystrophy in the child and adrenomyeloneuropathy. Study of 2 families]

Ten subjects from 2 families with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN), hereditary X-linked diseases, were systematically explored. We performed endocrinological, biochemical assays and neurophysiological tests; the latter consisted of nerve conductions (CNV), Hoffmann's reflex and multimodal evoked potentials: visual (flash and pattern, VEP), brainstem auditory (BAEP) and somesthetic (SEP) using median nerve stimulation at the wrist. We only considered values above 2 SD. The purpose of our study was to determine the correlation between neurophysiological and endocrinological perturbations and the presence of pathological traits. Our results suggest that the correlation is high in diseased male patients, lower for the ALD carriers (BAEP, SEP and CNV were more frequently abnormal) and very low for the AMN carriers. Only the biochemical assays appeared to have any value for the characterization of female carriers of ALD and AMN.

Adrenoleukodystrophy: impaired oxidation of fatty acids due to peroxisomal lignoceroyl-CoA ligase deficiency

Very long chain fatty acids (lignoceric acid) are oxidized in peroxisomes and pathognomonic amounts of these fatty acids accumulate in X-adrenoleukodystrophy (X-ALD) due to a defect in their oxidation. However, in cellular homogenates from X-ALD cells, lignoceric acid is oxidized at a rate of 38% of control cells. Therefore, to identify the source of this residual activity we raised antibody to palmitoyl-CoA ligase and examined its effect on the activation and oxidation of palmitic and lignoceric acids in isolated peroxisomes from control and X-ALD fibroblasts. The normalization of peroxisomal lignoceric acid oxidation in the presence of exogenously added acyl-CoA ligases and along with the complete inhibition of activation and oxidation of palmitic and lignoceric acids in peroxisomes from X-ALD by antibody to palmitoyl-CoA ligase provides direct evidence that lignoceroyl-CoA ligase is deficient in X-ALD and demonstrates that the residual activity for the oxidation of lignoceric acid was derived from the activation of lignoceric acid by peroxisomal palmitoyl-CoA ligase. This antibody inhibited the activation and oxidation of palmitic acid but had little effect on these activities for lignoceric acid in peroxisomes from control cells. Furthermore, these data provide evidence that peroxisomal palmitoyl-CoA and lignoceroyl-CoA ligases are two different enzymes.

Adrenoleukodystrophy: heterogeneity in two brothers

A man with hypoadrenalism died from a rapidly progressive pseudobulbar palsy, due to adult onset adrenoleukodystrophy. This diagnosis suggested that his brother, with a longstanding spastic paraparesis, suffered from adrenomyeloneuropathy. Both cases were confirmed biochemically. The heterogeneity of expression of this x-linked disorder is described, with the consequent difficulty in diagnosis and nomenclature.

Adrenoleukodystrophy and other peroxisomal disorders that affect the nervous system, including new observations on L-pipecolic acid oxidase in primates

Impaired nervous system function in childhood is encountered in 10 separate disorders of the peroxisome. Peroxisomal disorders are subdivided into three major groups. In group 1 there is failure to form the organelle and impairment of multiple peroxisomal functions. In group 3 peroxisome structure is intact and the defect involves a single enzyme. In group 2 (rhizomelic chondrodysplasia punctata) peroxisome structure is probably intact, but at least 2 peroxisomal enzymes fail to function normally. We present an overview of this newly recognized field which is so pertinent to brain development. In addition, we present recent and new data about the biochemical defect, genetics and therapy of X-linked adrenoleukodystrophy; about the normal metabolism of L-pipecolic acid in primates and its disturbance in the Zellweger syndrome, and about the prenatal diagnosis of peroxisomal disorders.

An adult onset metachromatic leukodystrophy with dominant inheritance and normal arylsulphatase A levels

A family with a variant of adult onset metachromatic leukodystrophy is presented. Clinical details from three affected members are given. The neurophysiological and neuroradiological data on the two brothers who have been recently studied are included. One of these died and the post-mortem findings are discussed along with those from a cousin who died some years ago. Arylsulphatase A levels were normal in both brothers yet the histological findings in the one who died are of a metachromatic leukodystrophy and thin-layer chromatography confirms an excess of sulphatides in the white matter of his brain. Disabling hypotension was a striking feature in both brothers but adrenal function was shown to be intact and autonomic neuropathy seemed the likely cause. Study of the family suggests a dominant mode of inheritance.

Peroxisomal lignoceroyl-CoA ligase deficiency in childhood adrenoleukodystrophy and adrenomyeloneuropathy

We previously reported that in childhood adrenoleukodystrophy (C-ALD) and adrenomyeloneuropathy (AMN), the peroxisomal beta-oxidation system for very long chain (greater than C22) fatty acids is defective. To further define the defect in these two forms of X chromosome-linked ALD, we examined the oxidation of [1-14C]lignoceric acid (n-tetracosanoic acid, C24:0) and [1-14C]lignoceroyl-CoA (substrates for the first and second steps of beta-oxidation, respectively). The oxidation rates of lignoceric acid in C-ALD and AMN were 43% and 36% of control values, respectively, whereas the oxidation rate of lignoceroyl-CoA was 109% (C-ALD) and 106% (AMN) of control values, respectively. On the other hand, the oxidation rates of palmitic acid (n-hexadecanoic acid) and palmitoyl-CoA in C-ALD and AMN were similar to the control values. These results suggest that lignoceroyl-CoA ligase activity may be impaired in C-ALD and AMN. To identify the specific enzymatic deficiency and its subcellular localization in C-ALD and AMN, we established a modified procedure for the subcellular fractionation of cultured skin fibroblasts. Determination of acyl-CoA ligase activities provided direct evidence that lignoceroyl-CoA ligase is deficient in peroxisomes while it is normal in mitochondrial and microsomes. Moreover, the normal oxidation of lignoceroyl-CoA as compared with the deficient oxidation of lignoceric acid in isolated peroxisomes also supports the conclusion that peroxisomal lignoceroyl-CoA ligase is impaired in both C-ALD and AMN. Palmitoyl-Coa ligase activity was found to be normal in peroxisomes as well as in mitochondria and microsomes. This normal peroxisomal palmitoyl-CoA ligase activity as compared with the deficient activity of lignoceroyl-CoA ligase in C-ALD and AMN suggests the presence of two separate acyl-CoA ligases for palmitic and lignoceric acids in peroxisomes. These data clearly demonstrate that the pathognomonic accumulation of very long chain fatty acids in C-ALD and AMN is due to a deficiency of peroxisomal very long chain (lignoceric acid) acyl-CoA ligase.

The contribution of pathology to the study of storage disorders

Our purpose is to illustrate some contributions of pathology to a better knowledge of metabolic disorders affecting the brain and visceral organs. Four groups of diseases are used to that effect. A comparative study of pre- and postnatal examples of mucopolysaccharidoses I, II and III reveals for example that severe neuronal lesions are already found in fetuses and that a rough parallelism exists between the maturation of neurons and the progressive intralysosomal accumulation of undigested metabolites. The study of four patients with I-cell disease shows that the intralysosomal storage occurs nearly exclusively in fibroblasts. Since the enzyme defect has also been found in non-mesenchymal cells, other mechanisms for a proper processing of lysosomal enzymes must be available in the intact cells. Adrenoleukomyeloneuropathy is used to demonstrate that the morphological features witnessing the accumulation of the very long chain fatty acids can be different in the central and in the peripheral nervous system. Finally, juvenile dystonic lipidosis illustrate the heterogeneity of the conditions grouped under the denomination of sphingomyelinoses. These few examples confirm the role of pathology in the diagnosis of metabolic disorders and in the study of their physiopathogenesis.

Clinical biochemistry of peroxisomal disorders

Peroxisomes have been shown to participate in a variety of pathological processes. Peroxisomal anomalities are central features of Zellweger's cerebro-hepato-renal syndrome, neonatal adrenoleukodystrophy, infantile Refsum's disease and several other genetic metabolic disorders (pseudo-Zellweger syndrome, Leber congenital amaurosis, cerebrotendinous xanthomatosis, rhizomelic chondrodysplasia punctata). In disorders with general loss of peroxisomal functions (Zellweger syndrome, neonatal adrenoleukodystrophy, infantile Refsum's disease) an accumulation of very long-chain fatty acids and pathological bile acids are found. Patients have a defective synthesis of plasmalogens and show increased excretion of dicarboxylic acids of medium chain length and of pipecolic acid in the urine. These anomalities which are due to the lack of peroxisomal enzymes, supply the basis for clinical laboratory tests. The study of these peroxisomal disorders has presented valuable information on the normal function of peroxisomes.

Effects of long-chain, saturated fatty acids on membrane microviscosity and adrenocorticotropin responsiveness of human adrenocortical cells in vitro

Adrenoleukodystrophy (ALD) and adrenomyeloneuropathy are inherited disorders in which long-chain, saturated fatty acids (LCFA) accumulate in various tissues. A mechanism by which LCFA cause the endocrine and neurological dysfunction characteristic of these diseases is proposed based on in vitro response of human adrenocortical cells to ACTH in the presence of various fatty acids. Human adrenocortical cells cultured in the presence of 5 microM hexacosanoic (C26:0) or lignoceric (C24:0) acids showed decreased basal and ACTH-stimulated cortisol release compared with cells cultured without exogenous fatty acids or in the presence of linoleic acid (C18:2). Measurement of fluorescence polarization demonstrates a significant increase in the membrane microviscosity of cells cultured in the presence of LCFA. It is hypothesized that cells exposed to LCFA have increased membrane microviscosity with a consequent decrease in their ability to respond to ACTH. This decrease in trophic support may contribute to the adrenal insufficiency and atrophy in patients with ALD.

Phenotypic and genotypic variability of generalized peroxisomal disorders

This article classifies and describes the various entities that comprise the generalized peroxisomal disorder. The variability in both phenotype and genotype is stressed. A heretofore undescribed generalized peroxisomal disorder is reported.

Adrenoleukodystrophy: frequency of presentation as a psychiatric disorder

Adrenoleukodystrophy (ALD) is an inheritable clinical disorder in which very long chain fatty acids accumulate in several tissue types. ALD is underrepresented in the psychiatric literature, although the disorder may cause an organic brain syndrome, often misdiagnosed as another psychiatric problem. A survey of 109 reported cases of ALD revealed that 39% presented with some psychiatric sign or symptom, whereas 17% presented exclusively as a psychiatric problem. A computed axial tomogram (CAT) head scan is recommended to rule out ALD in psychiatric patients suspected of having organic brain disease, as a characteristic image may be found in ALD patients who have brain involvement.

Adrenoleukodystrophy in an adult female. A clinical, morphological, and neurochemical study

A 43-year-old female with adrenoleukodystrophy (ALD) is described, who developed spastic tetraparesis, suffered grand mal seizures, and became stuporous and demented during the last 5 years of her life. Computed tomography revealed symmetrical hypodense lesions in the peritrigonal regions. Adrenal insufficiency was not evident except for skin pigmentation. The ultrastructure of a rectal biopsy specimen showed inclusions with lamellae and interspersed clefts in macrophages of the submucosal layer. At autopsy, the adrenals were found to contain large foam cells filled with similar inclusions. The brain cortex and the spinal cord were histologically normal. However, cerebral white matter exhibited widespread demyelination which spared only the arcuate fibres. In regions of less severe demyelination scattered inflammatory cells were seen. On electron microscopy, aggregates of typical paired leaflets with distinct intermediate lines were demonstrated in perivascular macrophages. Histochemical study showed these cells to contain free as well as esterified cholesterol. Gas chromatographic analysis of very long chain fatty acids (VLFA) from the demyelinated cerebral white matter showed a marked increase of C26:0 fatty acid in cholesterol esters and above-normal values for C24:0 and C24:1 in gangliosides. It is suggested that the condition was a heterozygote form of X-linked ALD. Patients with neurodegenerative symptoms with or without adrenal insufficiency can easily be screened for X-linked ALD by VLFA analysis in blood or cultured fibroblasts.

Peroxisomal disorders. A review of a recently recognized group of clinical entities

The peroxisome is a small organelle present in almost all cells. The peroxisomal disorders are a newly recognized group of disease entities that share structural and/or functional abnormalities of the peroxisomes, are inherited, and may have profound neurologic and systemic effects. Some of the disorders lack peroxisomes in cells, while others have single or multiple peroxisomal enzymatic deficiencies despite the presence of normally appearing peroxisomes. The prototype of the peroxisomal disorders is Zellweger syndrome. X-linked adrenoleukodystrophy, neonatal adrenoleukodystrophy, infantile Refsum disease, hyperpipecolic acidemia and Refsum disease are some of the other disease entities presently classified as peroxisomal disorders. Accurate methods of pre- and postnatal diagnosis are available. Treatment strategies are being developed, but at this time prenatal diagnosis and appropriate genetic counseling is the best therapeutic intervention for those peroxisomal disorders characterized by profound neurologic handicap and early death.

Adrenoleukodystrophy in a mother and son

A 6 year old boy died from a degenerative brain disease which was clinically and pathologically typical of adrenoleukodystrophy. Shortly before his disease became manifest his 28 year old mother had presented with similar symptoms, and subsequently died. Her brain showed almost identical features including the presence of pathognomonic ultrastructural inclusions. The accumulation of very long chain fatty acids in cerebral white matter as well as high hexacosanoic to docosanoic acid (C26:22) ratios, substantiated the diagnosis in both cases. This is one of the few documented cases of adrenoleukodystrophy in an adult female, and is almost certainly an example of clinical manifestation of this X-linked inherited disease in a carrier.

Adult adrenoleukodystrophy: a sporadic case?

This is a report of a case of the adult cerebral form of X-linked ALD. The 27-year-old patient presented with psychiatric disturbances. NMR was performed and compared to CT scan to define cerebral demyelination. The level of hexacosanoate was found to be increased in the patient's serum. Biochemical analysis of the patient's mother's serum and cultured fibroblasts and of serum samples from 10 other members of the family who could have been carriers of this X-linked disease, produced negative results. Hence, it is most likely that this case has occurred sporadically. HLA determination revealed the DR2 antigen which is often associated with multiple sclerosis.

Adrenoleukodystrophy: from bedside to molecular biology

Although X-linked adrenoleukodystrophy was first described in 1923, the key advances in understanding the disorder followed discoveries beginning in 1973 that it was characterized by the tissue accumulation of very long chain fatty acids, particularly hexacosanoic acid (C26:0). Very long chain fatty acid assays in plasma, red cells, fibroblasts, or amniocytes permit prenatal and postnatal diagnosis and carrier detection. The phenotype of X-linked adrenoleukodystrophy is varied and ranges from the severe and fatal childhood form, to persons who remain asymptomatic in adult life. The underlying biochemical defect is the impaired capacity to degrade very long chain fatty acids, a reaction which normally takes place in the peroxisome. The locus of the adrenoleukodystrophy gene has been mapped to the terminal (Q28) segment of the long arm of the X-chromosome, in close proximity to the loci of Hemophilia A and red-green color blindness. A DNA probe (St14) for this portion of the X-chromosome is of aid for carrier detection. A new dietary regimen, which combines restricted very long chain fatty acid intake with the administration of a glycerol trioleate oil, is capable of reducing plasma very long chain fatty acid levels, and may offer neurological benefit.

The inherited neurodegenerative disorders of childhood: clinical assessment

This review represents an examination of four groups of neurodegenerative diseases, namely the sphingolipidoses, the adrenoleukodystrophy complex, the neuronal ceroid lipofuscinoses, and the sialidoses/sialuria complex. Using a combination of clinical assessment, neuroradiologic appearance, and clinical neurophysiology, one may develop strategies that lead to specific chemical or biochemical determinations for specific diagnoses. In general, disorders of white matter may be distinguished from disorders of gray matter by their appearance on computed tomography and by abnormalities of nerve conduction velocities and auditory brain stem responses. In contrast, disorders of gray matter may be distinguished from disorders of white matter by their appearance on computed tomography and utilization of electroretinography, visual evoked responses, and, to a lesser extent, EEG findings. Where necessary, skin, conjunctival, or nerve biopsy may prove to be useful adjuncts to the diagnosis. Presently, treatment depends on prevention, although aggressive efforts are under way to establish corrective therapy by enzyme replacement. To this end, the use of already existing animal models may prove to be helpful.

A new dietary therapy for adrenoleukodystrophy: biochemical and preliminary clinical results in 36 patients

A new dietary regimen has been administered for periods ranging from 60 days to 1 1/2 years in 34 patients with various forms of X-linked adrenoleukodystrophy (ALD), as well as in 1 patient with neonatal ALD and 1 patient with infantile Refsum's disease. The diet combines the administration of a glyceryl trioleate oil (GTO) with the dietary restriction of very-long-chain fatty acids (VLFA), particularly hexacosanoic acid (C26:0). Reductions in the levels of plasma C26:0 and other VLFA were achieved in 25 of the 36 patients. Fifteen of these 25 patients were treated for more than 100 days. The mean reduction of the plasma C26:0 level was 53% (range, 22 to 73%) in these 15 patients. While the focus of the study was on biochemical variables, comparison of pre- and post-diet studies of peripheral nerve function showed improvement in 1 patient with adrenomyeloneuropathy (AMN) and 1 heterozygote. In contrast, 2 patients with ALD onset in childhood developed new neurological deficits while on therapy. We conclude that it is possible to lower plasma VLFA levels in ALD patients. A clinical trial is indicated to test whether this approach can alter the neurological progression in patients with AMN or in symptomatic heterozygotes, and to determine whether it can prevent the onset of neurological disability in asymptomatic persons who have the biochemical defect of ALD.

Neonatal adrenoleukodystrophy. Impaired plasmalogen biosynthesis and peroxisomal beta-oxidation due to a deficiency of catalase-containing particles (peroxisomes) in cultured skin fibroblasts

Neonatal adrenoleukodystrophy belongs to the newly recognized group of inherited diseases, the peroxisomal disorders. Based on the reported similarities between neonatal adrenoleukodystrophy and the cerebro-hepato-renal (Zellweger) syndrome, we have studied peroxisomal functions in cultured skin fibroblasts from 5 neonatal adrenoleukodystrophy patients. The results indicate that multiple peroxisomal enzyme activities are deficient in fibroblasts from neonatal adrenoleukodystrophy patients. Digitonin titration experiments revealed that peroxisomes are strongly deficient in these fibroblasts as found earlier in fibroblasts from Zellweger patients. These findings not only explain the generalized loss of peroxisomal functions in neonatal adrenoleukodystrophy, but also provide an explanation for the observed resemblance in clinical and biochemical abnormalities between neonatal adrenoleukodystrophy and Zellweger syndrome. The implications for the pre- and postnatal detection of this disease will be discussed.

Peroxisomal disorders

The different types of adrenoleukodystrophy are considered with their clinical and biochemical features, particularly the excess of very-long-chain fatty acids. Then other conditions which show this latter finding are described, including the Zellweger cerebrohepatorenal syndrome, hyperpipecolic acidemia and Refsum disease. The role of peroxisomes is discussed and the different ways in which their functions can be disordered. The possibilities of treating these diseases is at the moment limited but examples are given of research already carried out in this field.

Familial spinocerebellar degeneration as an expression of adrenoleukodystrophy

A family with adrenoleukodystrophy and clinical manifestations of spinocerebellar degeneration was studied. Two adult male first cousins showed progressive limb and truncal ataxia, slurred speech and spasticity of the extremities. Brain CT scans demonstrated atrophy of the pons and cerebellum, in both cases. Very long chain fatty acids in plasma and erythrocyte membranes were elevated in the affected patients and intermediately increased in an aunt and the mother of one patient, thereby indicating homozygotes and carriers of adrenoleukodystrophy, respectively. This unusual type of adrenoleukodystrophy seems to be transmitted as an X-linked recessive trait.

Effects of subperineurial injections of very-long-chain and medium-chain fatty acids into rat sciatic nerve

[9,10-3H] palmitic (C16:0) and [1-14C] lignoceric (C24:0) acid dissolved in 10 microL of ethanol were injected subperineurially into the sciatic nerve of rats. Both C16:0 and C24:0 were incorporated into lipids, and in most lipid fractions C16:0 incorporation exceeded that of C24:0. Free ceramide and cholesterol ester were the only lipid moieties in which C24:0 incorporation was equal to or greater than that of C16:0. This finding is of particular interest since the very-long-chain fatty acid excess is by far the most striking in the cholesterol ester fraction in adrenoleukodystrophy. Furthermore, incorporation into cerebroside and sulfatide indicates that at least some of the injected fatty acids were metabolized in the Schwann cell. Subperineurial injections of either very-long-chain fatty acids or medium-chain fatty acids into rat sciatic nerve caused demyelination, and this morphological change does not occur following injection of pure solvent.

Adrenoleukodystrophy and variants. Clinical, neurophysiological and biochemical studies in patients and family members

Clinical, neurophysiological and biochemical studies were performed in patients with various forms of adrenoleukodystrophy (ALD) and their family members. The patients showed an abnormality in saturated very long chain fatty acids and in the somatosensory and brain stem auditory or visual evoked potentials. Female presumptive carriers without abnormal neurological manifestations also showed abnormality in the somatosensory or brain stem auditory evoked potentials and in saturated very long chain fatty acids. One ALD patient and his mother, a female carrier, had the decreased beta-galactosidase activity. The increase in saturated very long chain fatty acids was found, not only in sphingomyelin, but also in phosphatidylcholine and phosphatidylserine. Our results suggest that a generalized abnormal metabolism of VLFA and an abnormality in the central nervous system exist in our patients and female carriers.

Adrenoleukodystrophy: evidence for cytoplasmic inclusions in white blood cells

Adrenoleukodystrophy (ALD) is a progressive neurological demyelinating disease associated with adrenal insufficiency. Pathognomonic lamellar profiles and clear clefts have been observed in several organs and tissues. We describe similar ultrastructural lamellar lipid profiles in white blood cells from 2 patients with ALD. It is suggested that electron microscopy of white blood cells may be a simple and effective screening method in patients presenting with a clinical picture suggestive of ALD.

Neonatal adrenoleukodystrophy

Nine cases of neonatal adrenoleukodystrophy are described. All patients had abnormal facial features, moderate to severe hypotonia, hepatomegaly, and retinitis pigmentosa. The clinical course was rapidly progressive in six cases and more protracted in three others. Biological signs of adrenal insufficiency were present in five cases. CT scan showed a demyelinating process in four patients. Trilamellar inclusions were found in the liver of four cases and dark and complex lipidic inclusions in three other cases. In the three necropsied patients there was severe alteration of the white matter involving particularly the cerebellum in two cases. Gyral and cytoarchitectonic disturbances were absent in all three cases. Increased plasma levels of very long chain fatty acids (8/8), phytanic acid (7/8) and bile fluid trihydroxycoprostanic acid (2/4) confirmed the deficiency of multiple peroxisomal enzymes. Clinical, histopathological and biochemical findings of these nine cases are compared to those reported in other neonatal adrenoleukodystrophy cases and to those of other neonatal peroxisomal disorders, that is cerebro-hepato-renal syndrome of Zellweger and infantile Refsum's disease.

Metabolism of [17,18-3H2]hexacosanoic acid and [15,16-3H2]lignoceric acid in cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN)

We have studied the metabolism of [17,18-3H2]hexacosanoic acid and [15,16-3H2]lignoceric acid in cultured skin fibroblasts from patients with adrenoleukodystrophy (ALD) and adrenomyeloneuropathy (AMN). The successful solubilization of the very long chain fatty acids as albumin conjugates was confirmed by analysis using glycerol density gradient centrifugation. The composition of radioactive fatty acids in total lipids of fibroblasts after culture for 7 days in the presence of [17,18-3H2] hexacosanoic acid or [15,16-3H2]lignoceric acid was analyzed by radio-gas chromatography. Most of the fatty acids added to the culture media were degraded to shorter-chain fatty acids both by control, and ALD or AMN fibroblasts. However, the content of the remaining radioactive hexacosanoic acid or lignoceric acid was much higher in ALD or AMN fibroblasts, and the content of radioactive shorter-chain fatty acids was much lower in ALD or AMN fibroblasts. These results indicate that the degradation of very long chain fatty acids is decreased in ALD, but also that there is a substantial amount of residual activity of their degradation in ALD fibroblasts.

Adrenomyeloneuropathy: report of a family and electron microscopical findings in peripheral nerve

A family with adrenomyeloneuropathy (AMN) is reported, whose female carriers showed severe neurological and biochemical abnormalities. Cytoplasmic lamellar inclusions were found in endoneurial cells of the biopsied sural nerve of a male patient. In spite of the peripheral nervous system involvement in patients with AMN, there have been few reports of these inclusions in the peripheral nerves of such cases.