Cerebral Degenerations of Childhood Canavan Disease (Spongy Degeneration of the Nervous System) Autosomal recessive megalencephaly and neurologic degeneration. Prevalent among Ashkenazi Jews from eastern Europe and among Saudi Arabians. Clinical…
Neurologic Syndromes with Acanthocytes Acanthocytes (“thorny” erythrocytes) seen in three hereditary neurologic syndromes: abetalipoproteinemia, neuroacanthocytosis, McLeod syndrome. Abetalipoproteinemia (Bassen-Kornzweig Syndrome) Autosomal recessive; inability of liver and intestine to secrete apolipoprotein…
Acute Intermittent Porphyria Neurologic manifestations in two classes: acute intermittent porphyria (AIP) and variegate porphyria. Both autosomal dominant, low penetrance. Prevalence worldwide approximately 1:100,000. More common in women than men….
Disorders of Metal Metabolism Hepatolenticular Degeneration (Wilson Disease) Inborn error of copper metabolism; with liver cirrhosis, basal ganglia degeneration. Worldwide prevalence: 30 per 1 million. Pathogenesis and Pathology Autosomal recessive….
Organic Acidurias Inborn errors of metabolism leading to accumulation of organic acids. As a group, common cause of infantile encephalopathy due to inherited metabolic diseases. Rapid diagnosis crucial: some curable;…
Peroxisomal Diseases: Adrenoleukodystrophy, Zellweger Syndrome, Refsum Disease Peroxisomal functions: degrade very long chain fatty acids (VLCFA); initiate synthesis of plasmalogens (myelin sheath lipids). Classification Peroxisome biogenesis disorders: abnormalities in more…
Hyperammonemia Causes of high blood ammonia levels: Table 88.1. Differential diagnosis differs according to age of patient. Table 88.1 Major Causes of Hyperammonemia Newborn Period Asymptomatic infant Transient hyperammonemia of the…
Disorders of DNA Maintenance, Transcription, and Translation May be caused by abnormality in: (1) DNA repair following exposure to mutagens (nucleotide excision repair); (2) DNA duplication and transcription, (3) RNA…
Glucose Transporter Type 1 Deficiency Syndrome Clinical features: usual presentation is with seizures in early infancy. Variable features: delayed motor development, microcephaly, ataxia, hypotonia, spasticity. Isolated mental retardation or choreoathetosis…
Disorders of Carbohydrate Metabolism Glycogen Storage Diseases Abnormal metabolism of glycogen, glucose. Due to specific enzyme deficiency (Table 85.1). May present with: fasting hypoglycemia, pathologic glycogen storage (e.g., hepatomegaly), or…
