Inherited Leukoencephalopathies

SUMMARY:

Recent years have seen a significant expansion in our understanding about the genetic causes of inherited leukoencephalopathies in both children in adults. The aim of this symposium is to provide a practical clinical approach to the patient with leukoencephalopathy and to update recent knowledge. Despite this increase in knowledge, approximately 50% of patients remain undiagnosed.

LEARNING OBJECTIVES:

1. To review a practical clinical approach to the patient with an undiagnosed leukoencepaphalopathy.
2. To provide an update of recent developments in our understanding of the genetic etiology of inherited leukoencephalopathies.
3. To encourage collaboration leading to the discovery of new causes of inherited leukoencephalopathy.

SPEAKERS

1. Clinical approach to leukodystrophies/ inherited leukoencephalopathies
   Dr.Sakku Naidu, Kennedy Kreiger Institute, Baltimore, Maryland
2.  
3. Leukoencephalopathies associated with macrocephaly
   Dr. Deborah Renaud, Mayo Clinic, Rochester, Minnesota
4.  
5. Peroxisomal leukoencephalopathy
   Dr. Bwee-Tien Poll-The, AMC, Amsterdam, Netherlands

Peroxisomal leukoencephalopaties include diseases belonging to the Zellweger spectrum and the rhizomelic chondrodysplasia punctata spectrum, as well as some single enzyme defects of peroxisomal ß-oxidation. MRI's of patients belonging to thevZellweger spectrum may show developmental anomalies and regressive changes consisting of abnormal cerebral white matter. Involvement of the central white matter of the cerebellar hemispheres is frequently seen. The leukoencephalopathy is progressive, with or without peripheral nerve involvement, in patients with a prolonged course of the disease. MRI characteristics in the severe phenotype of rhizomelic chondrodysplasia punctata include supratentorial white matter abnormalities, with a parieto-occipital predominance. Demyelinative lesions are the hallmark of the cerebral form of X-linked adrenoleukodystrophy and may appear in a similar way in patients with adrenomyeloneuropathy progressing to a cerebral form. The diagnosis of a peroxisomal disorder can be determined by a battery of biochemical assays in blood and/or urine, and should be confirmed in cultured fibroblasts and DNA analysis. Treatment of the peroxisomal leukoencephalopathies is largely symptomatic, except for boys affected by the cerebral form of X-linked adrenoleukodystrophy in whom a bone marrow/hematopoietic stem cell transplant can be life saving, at least in the early stages of the disease.

KEYWORDS: Peroxisomal disorders, Zellweger spectrum disorders, rhizomelic chondrodysplasia punctata, X-linked adrenoleukodystrophy, leukodystrophy.

Update on new leukodystrophies
Dr.Deborah Renaud