Juvenile metachromatic leukodystrophy: evoked potentials and computed tomography.

Gene therapy offers new hope for children with metachromatic leukodystrophy

Chemical studies of two cerebral biopsies in juvenile metachromatic leukodystrophy: The molecular composition of cerebrosides and sulfatides

In a child with enzymatically and histopathologically proven metachromatic leukodystrophy (MLD), the disease pursued a course typical of juvenile MLD characterized by neurological degeneration beginning at age 9 years and ending in death at age 18. A younger brother of the patient was found to have profound deficiency of arylsulfatase A in leukocytes and to excrete five- to 20-fold greater-than-normal amounts of sulfatide in the urine. He was completely free of symptoms attributable to MLD until age 16 when he developed acute cholecystitis caused by sulfatide accumulation in the gallbladder. Results of detailed neurological examination at age 21 years were normal; formal psychometric assessment showed a full-scale IQ of 105 (Wechsler). Studies on cultured skin fibroblasts from the brother showed defects in arylsulfatase A activity, measured with the use of synthetic and natural substrates, and in radiolabeled sulfatide turnover. Cellulose acetate gel electrophoresis of fibroblast extracts from the patient showed no detectable arylsulfatase A isozyme under conditions that clearly distinguished pseudo-arylsulfatase A deficiency from classical MLD. Biochemically, the patient was indistinguishable from patients with classical MLD; on the other hand, his clinical course is dramatically more benign than that of his sister who was affected with severe MLD.

Metachromatic leukodystrophy (MLD) is a rare inherited disorder of the white matter with higher incidences in consanguineous populations. In children, manifestations vary with age of onset: early forms present with motor regression and developmental delay, whereas later forms begin with motor difficulties followed by behavioural or cognitive decline. We describe a 7-year-old boy with previously normal development who exhibited progressive motor deficits, speech difficulties, cognitive impairment, and loss of bladder control. Neurological examination revealed generalized hypotonia, areflexia, gait ataxia, and axial spasticity. Audiovisual function was preserved. Laboratory workup showed elevated urinary sulfatide levels despite normal enzymatic activity of the main sulfatide-degrading enzyme. Additional metabolic tests were unremarkable aside from signs of increased ketone bodies. Neuroimaging revealed white matter abnormalities consistent with a leukodystrophic process, and electrophysiological studies confirmed peripheral demyelination. Genetic analysis revealed a homozygous PSAP c.777G>A variant, affecting a gene essential for sulfatide degradation and suggesting a possible atypical form of MLD. This case highlights the diagnostic complexity of non-classical presentations and underscores the value of comprehensive metabolic and genetic evaluation. This case illustrates that MLD can present with normal enzymatic assays and highlights the importance of combined biochemical, neuroimaging, and genomic testing in children with rapid motor and cognitive decline.

Juvenile metachromatic leukodystrophy caused by a rare genetic mutation.

Juvenile metachromatic leukodystrophy in a boy with epilepsy

Predicting clinical phenotypes of metachromatic leukodystrophy based on the arylsulfatase A activity and the ARSA genotype? - Chances and challenges.

Metachromatic leukodystrophy (MLD) is an autosomal recessive, lysosomal storage disease due to deficiency or absence of arylsulfatase A enzyme (ASA) with sulfatide accumulation in the central and peripheral nervous system, kidneys, and gallbladder, leading to many dysfunctions. One of the clinical forms of the disease is a late juvenile MLD. To our best knowledge, this is the first report describing increased Tau/pTau and normal Aβ1-42 concentrations in the CSF of the late juvenile MLD patient.

Neurodevelopmental Outcomes of Umbilical Cord Blood Transplantation in Metachromatic Leukodystrophy

Metachromatic leukodystrophy (MLD) is a lysosomal enzyme deficiency disorder leading to progressive demyelination and, consecutively, to cognitive and motor decline. Brain magnetic resonance imaging (MRI) can detect affected white matter as T2 hyperintense areas but cannot quantify the gradual microstructural process of demyelination more accurately. Our study aimed to investigate the value of routine MR diffusion tensor imaging in assessing disease progression. MR diffusion parameters (apparent diffusion coefficient [ADC] and fractional anisotropy [FA]) were in the frontal white matter, central region (CR), and posterior limb of the internal capsule in 111 MR datasets from a natural history study of 83 patients (age: 0.5-39.9 years; 35 late-infantile, 45 juvenile, 3 adult, with clinical diffusion sequences of different scanner manufacturers) as well as 120 controls. Results were correlated with clinical parameters reflecting motor and cognitive function. ADC values increase and FA values decrease depending on disease stage/severity. They show region-specific correlations with clinical parameters of motor and cognitive symptoms, respectively. Higher ADC levels in CR at diagnosis predicted a disease course with more rapid motor deterioration in juvenile MLD patients. In highly organized tissues such as the corticospinal tract, in particular, diffusion MR parameters were highly sensitive to MLD-associated changes and did not correlate with the visual quantification of T2 hyperintensities. Our results show that diffusion MRI can deliver valuable, robust, clinically meaningful, and easily obtainable/accessible/available parameters in the assessment of prognosis and progression of MLD. Therefore, it provides additional quantifiable information to established methods such as T2 hyperintensity.

We treated a 28-year-old woman who had metachromatic leukodystrophy with bone marrow transplantation. Leukocyte arylsulfatase A levels increased to the donor's range after successful graft. Motor and sensory nerve conduction values did not change significantly in the 4 years after the transplant, and subcortical white matter lesions, as shown on MRI, remained stable during that period of time. The results, after 4 years of follow-up, indicate that the disease has not progressed and signs and symptoms are stabilized.

Long‐term neuroimaging follow‐up on an asymptomatic juvenile metachromatic leukodystrophy patient after hematopoietic stem cell transplantation: Evidence of myelin recovery and ongoing brain maturation

SAP-1 is a sphingolipid activator protein found in human tissues required for the enzymatic hydrolysis of GM1 ganglioside and sulfatide. It appears to be missing in patients who have a genetic lipidosis resembling juvenile metachromatic leukodystrophy. Using rabbit antibodies against human SAP-1 it could be visualized in extracts from cultured human skin fibroblasts after sodium dodecylsulfate-polyacrylamide gel electrophoresis, followed by electroblotting to nitrocellulose membrane and immunochemical staining (Western blotting). A series of 23 human-Chinese hamster ovary cell hybrids containing different human chromosomes were examined. The parent Chinese hamster ovary cells did not have a reacting protein in the region of human SAP-1. Only in the eight hybrid clones containing human chromosome 10 was a reacting protein identified. Other chromosomes were excluded by this method. Therefore the gene for SAP-1 and the genetic mutation resulting in a fatal lipidosis are located on human chromosome 10.