X-linked Adrenoleucodystrophy Research Articles

Multiple sclerosis with adrenal insufficiency mimicking adrenoleucodystrophy

The diagnosis of multiple sclerosis (MS) is based on clinical, radiological and biological findings. A misinterpretation of non specific clinical and radiological findings may contribute to misdiagnosing MS mimickers such as inherited leucoencephalopathies. Mrs NS, a 28 year-old woman was referred to our unit for vertigos and gait disturbances evolving since 15 days. Neurological assessment showed central vestibular syndrome and deep sensory alterations. Brain and spinal cord MRI showed non enhancing T2 and Flair hyperintensities in the parieto-occipital periventricular white matter, cerebellar pedoncules and the cervical portion of the spinal cord. Lumbar puncture showed oligoclonal bands in cerebrospinal fluid. The visual evoked potentials showed bilateral optic demyelinating neuropathy. Biochemistry revealed adrenal insufficiency. The diagnosis of adrenoleucodystrophy in a carrier woman was plausible all the more we noted high Lactate-to-pyruvate ratio. However the dosage of Very-Long-Chain-Fatty-Acids was normal. Hence, the diagnosis of MS was made. The patient received five days pulsed-methylprednisolone and experienced rapid improvement. Many patients are misdiagnosed with multiple sclerosis, and might be given disease modifying therapies while they suffer from metabolic or systemic disorders mimicking inflammatory demyelinating diseases. There are many overlapping factors mainly: inflammation which is the underlying mechanism of X-linked adrenoleucodystrophy (X-ALD), demyelinating optic neuritis, the presence of oligoclonal bands in CSF which were reported in X-ALD patients. In our case we ruled out the diagnosis of X-ALD but this should be considered in patients with atypical MRI features or family history of adrenomyelopathy mainly in males.

Maladies peroxysomales

Peroxisomes are small intracellular organelles that catalyse key metabolic reactions such as the beta-oxidation of some straight-chain or branched-chain fatty acids and the alpha-oxidation of phytanic acid. These enzyme reactions produce hydrogen peroxide, which is subsequently neutralized by the peroxisomal catalase. Peroxisomes also metabolize glyoxylate to glycine, and catalyze the first steps of plasmalogen biosynthesis. There are more than a dozen inherited peroxisomal disorders in humans. These metabolic diseases are due to monogenic defects that affect either a single function (such as enzyme or a transporter) or more than two distinct functions because of the impairment of several aspects of peroxisome biogenesis. With the notable exception of X-linked adrenoleucodystrophy, these inborn disorders are transmitted as autosomal recessive traits. Their clinical presentation can be very heterogeneous, and include neonatal, infantile or adult forms. The present review describes the symptomatology of these genetic diseases, the underlying genetic and biochemical alterations, and summarizes their diagnostic approach.

Role of family D ATP-binding cassette transporters (ABCD) in cancer.

ATP-binding cassette (ABC) transporters, belonging to the family D, are expressed in peroxisomes, endoplasmic reticulum or lysosomes. ABCD transporters play a role in transport of lipids, bile acids and vitamin B12 and associate with peroxisomal disorders. ABCD1 performs transport of coenzyme A esters of very-long-chain fatty acids (VLCFA) in peroxisomes and a number of mutations in ABCD1 gene were linked to an X-linked adrenoleucodystrophy (X-ALD). The role of ABCD transporters in tumour growth has not been studied in detail, but there is some evidence that ABCDs levels differ between undifferentiated stem or tumour cells and differentiated cells suggesting a possible link to tumorigenesis. In this mini-review, we discuss the available information about the role of ABCD transporters in cancer.

Epilepsy in adult X-linked adrenoleucodystrophy due to the deletion c.1415-1416delAG in exon 5 of the ABCD1-gene

Seizures in cerebral X-linked adrenoleucodystrophy (X-ALD) more frequently occur in the early-onset compared to the late-onset form. Here we describe an adult in whom X-ALD deteriorated after head trauma and who developed epilepsy with progression of X-ALD.In a 50year-old Caucasian male, cerebral X-ALD was diagnosed upon progressive gait disturbance, intellectual decline, elevated very-long chain fatty acids in the serum or leucocytes, cerebral MRI, showing extensive, symmetric, homogenous demyelination in the parieto-occipital areas, the splenium corporis callosum, the thalamus, the crura cerebri, the brain stem, and the pedunculi cerebelli, and the deletion c.1415-1416delAG in the ABCD1-gene. After a head trauma the phenotype deteriorated to mutism, dysphagia, and severe spastic quadruparesis. At an age of 50years the patient experienced his first, self-limiting, tonic–clonic seizure during an infection, which is why valproic acid was started. Recurrence of seizures after discharge required repeated adaptation of the valproic acid-dosage.Adult X-ALD may be associated with late-onset seizures, which respond favourably to valproic acid. Since any type of seizure episode in adult-onset cerebral X-ALD is usually followed by neurological decline, prophylactic treatment with antiepileptic drugs should be considered not only in early-onset but also in adult-onset epilepsy in X-ALD.

Rapid quantification of conjugated and unconjugated bile acids and C27 precursors in dried blood spots and small volumes of serum

The aim of the study was to develop a method for fast and reliable diagnosis of peroxisomal diseases and to facilitate differential diagnosis of cholestatic hepatopathy. For the quantification of bile acids and their conjugates as well as C(27) precursors di- and trihydroxycholestanoic acid (DHCA, THCA), in small pediatric blood samples we combined HPLC separation on a reverse-phase C18 column with ESI-MS/MS analysis in the negative ion mode. Analysis was done with good precision (CV 3,7%-11.1%) and sufficient sensitivity (LOQ: 11-91 nmol/L) without derivatization. Complete analysis of 17 free and conjugated bile acids from dried blood spots and 10 microL serum samples, respectively, was performed within 12 min. Measurement of conjugated primary bile acids plus DHCA and THCA as well as ursodeoxycholic acid was done in 4.5 min. In blood spots of healthy newborns, conjugated primary bile acids were found in the range of 0.01 to 2.01 micromol/L. Concentrations of C(27) precursors were below the detection limit in normal controls. DHCA and THCA were specifically elevated in cases of peroxysomal defects and one Zellweger patient.

Syndromes associated with abnormalities in the adrenal cortex

Pathology of the adrenal cortex is a clinical manifestation of a number of different syndromes. These alterations include gross and microscopic findings, functional or asymptomatic conditions, and the entire spectrum of growth abnormalities, from hyperplasia to carcinoma. This review will cover syndromes that are associated with adrenal cortical tumours and hyperplasia, or with other specific adrenal cortical pathology, and those that are associated with congenital adrenal insufficiency. The syndromes associated with hyperplasia and tumour development include Beckwith-Wiedemann, Li-Fraumeni, Carney complex, McCune-Albright, multiple endocrine neoplasia type 1 and congenital adrenal hyperplasia. The syndromes associated with adrenal insufficiency include triple A syndrome, familial glucocorticoid deficiency and X-linked adrenoleucodystrophy. Adrenal calcification in Wolman syndrome will also be examined. The clinical, genetic, and histopathological features of each disease will be discussed.

Effect of dehydroepiandrosterone supplementation on fatty acid and hormone levels in patients with X‐linked adrenoleucodystrophy

In X-linked adrenoleucodystrophy (X-ALD) the peroxisomal beta-oxidation of saturated very long-chain fatty acids (VLCFAs; carbon length > 22 atoms) is impaired. These fatty acids accumulate in blood and tissues, in particular in the nervous system, adrenal cortex and testis. Most patients have a primary adrenocortical insufficiency with low levels of cortisol and dehydroepiandrosterone (DHEA) and its sulphate ester (DHEA-S), collectively called DHEA(S). Surprisingly, very low plasma levels of DHEA(S) may be found when plasma cortisol and ACTH levels are normal. In animal studies DHEA administration had a peroxisome proliferating effect and induced the expression of peroxisomal enzymes involved in the beta-oxidation of fatty acids. To study the effect of DHEA on fatty acids in X-ALD patients, we conducted a randomized double-blind study in which 14 men (age range 21-63 years) and one boy (12 years) received 50 mg of DHEA or placebo for 3 months, followed by a 1-month wash-out period, then 3 months of placebo or vice versa. A significant rise was seen in the plasma levels of DHEA-S, Delta4-androstenedione and IGF-I. The elevated saturated VLCFAs in plasma and erythrocytes did not change. However, in erythrocytes significant decreases were found in the total amount of fatty acids, in C16:0, C18:0 and in C20:4omega-6, C22:5omega-6, C18:1omega-9, C20:1omega-9 and C20:3omega-9. In plasma, decreases were found for C18:1omega-9 and increases for C20:1omega-9. Dehydroepiandrosterone supplementation for 3 months did not lower the elevated plasma levels of saturated very long-chain fatty acids in patients with X-linked adrenoleucodystrophy. Instead, a decrease in saturated and mono- and polyunsaturated fatty acids in erythrocytes and plasma was found. An increase of C20:1omega-9 was found in plasma only.

The importance of testing for adrenoleucodystrophy in males with idiopathic Addison's disease

X linked adrenoleucodystrophy (X-ALD) is considered to be a rare cause of Addison's disease, although several small series suggest a high incidence in young Addisonian males. A survey in the...

Variability of endocrinological dysfunction in 55 patients with X-linked adrenoleucodystrophy: clinical, laboratory and genetic findings.

X-linked adrenoleucodystrophy (ALD) has been shown to be one of the most frequent causes of Addison's disease in men. It is characterized by an impaired peroxisomal beta-oxidation of very long chain fatty acids and is associated with mutations of the ALD gene resulting in a defective peroxisomal membrane transport protein. There is a striking variability of endocrinological and neurological symptoms in patients with ALD, with no clearly evident correlation between mutations of the ALD gene and the different neurological phenotypes. No data on endocrinological symptoms and the ALD genotype have been published so far. We report endocrinological, clinical, laboratory and molecular genetic data from 55 patients with ALD from 34 families. Endocrinological symptoms of adrenal insufficiency were observed in 33 patients, 20 of whom showed additional neurological symptoms of cerebral ALD or adrenomyeloneuropathy. Isolated neurological symptoms were seen in 12 patients; in nine patients there were neither endocrinological nor neurological symptoms. Mutations of the ALD gene (n = 28) were detected in 50 patients (including nine sets of brothers) from 32 families. No correlation was found between the ALD gene mutation and endocrinological dysfunction. However, we found that all sets of brothers were concordant for the endocrinological phenotype (cortisol synthesis was reduced in two sets and normal in seven sets), whereas four sets showed a discordant neurological phenotype. As yet unknown hereditary factors other than mutations within the ALD gene may interfere with the endocrinological phenotype more strongly than with the neurological phenotype of ALD.

Red blood cell ghosts are affected by adrenoleucodystrophy.

X-linked adrenoleucodystrophy is a disorder occurring in different clinical forms, characterized by adrenal, gonadal and nervous system dysfunction. The basis of the illness is a derangement of the peroxisomal system necessary to oxidize very long-chain fatty acids that accumulate in various tissues. The diagnosis relies on clinical signs and symptoms and on biochemical findings. The six reported cases presented idiopathic adrenal insufficiency. We measured the lipid composition of red blood cell (RBC) ghosts of patients and control subjects. The distribution of phosphorus among phospholipid classes was unaffected; we could not demonstrate any differences between the fatty acid patterns of RBC membrane, either in total lipid extracts or in separated lipid classes. However, we found an increase in total lipid (both phospholipid and cholesterol), in membrane viscosity and in the Na+/K(+)-dependent ATPase. Therefore, we report four main findings on ghosts in adrenoleucodystrophy patients: (a) very long-chain fatty acids do not accumulate; (b) the lipid-protein ratio increases; (c) fluidity decreases; and (d) the activity of ATPase increases. The last finding is proposed as a possible biochemical marker of the illness. We conclude that adrenoleucodystrophy affects deeply RBC membranes.

Pitfalls in the prenatal diagnosis of peroxisomal β‐oxidation defects by chorionic villus sampling

Variability in the level of expression of very long chain fatty acids (VLCFAs) is documented in cultured chorionic villus (CV) cells derived from two fetuses, one at risk for an unusual peroxisomal fatty acid beta-oxidation defect, and the other at risk for the X-linked form of adrenoleucodystrophy (ALD). Cells from early subcultures of chorionic cells from both cases gave normal values for VLCFA ratios. The results for the fetus at risk for the beta-oxidation defect were interpreted to indicate that the fetus was not affected; however, at birth, the infant was clinically and biochemically affected. In the case of the fetus at risk for X-linked ALD, although VLCFAs were normal in subculture 1, the levels of these fatty acids increased dramatically in subculture 3, suggesting an abnormal fetus. Termination of the pregnancy and subsequent biochemical and morphological follow-up confirmed that the fetus was indeed affected by ALD.