M uch regarding adrenoleukodystrophy (X-ALD) has changed in the 25 years since the first edition of this book was published, including substantial increases in understanding the medical aspects of these diseases, their clinical management, and increased patient advocacy and support services throughout the United States and the world. Still, they remain difficult and highly complex disorders for families to navigate and endure. The saga of Augusto and Michaela Odone's quest to save the life of their 5-year-old son Lorenzo, dramatized in the 1992 film Lorenzo's Oil, brought X-ALD to the wider audience. X-ALD is a genetic metabolic disease that impairs the white myelin sheath surrounding the nerves of the brain, spinal cord, and peripheral nerves, a process known as demyelination, as well as the adrenal cortex and the testis (H. W. Moser, 2006). The myelin sheath permits nerve impulses to be conducted rapidly and efficiently, and as demyelination occurs, nerve functions become erratic, resulting in a variety of physiological and behavioral symptoms: motor dysfunctions involving changes in body tone, gait, and speech; inability to eat; inability to see and hear; deficient memory and attention; unstable emotional behaviors; and inefficient cognitive processing.
ETIOLOGYX-ALD is caused by mutations in the ABCD1 gene on the q28 part of the X chromosome, which encodes the membrane protein ALDP involved in the