Canavan Disease Report

Biology Class Grade 11

Introduction Among the many deadly genetic diseases in our world today the Canavan Disease is one of the most tragic ones of all as it’s a disease that causes ongoing damage to the nerve cells in the brain and doesn’t allow the infected to survive long. This disease was discovered in 1931 by Myrtelle Canavan, a researcher (1). The Canavan Disease’s gene was first discovered by Dr. Rueben Matalon after seeing this gene terrorize many families in his hometown as quoted by National Tay-Sachs & Allied Diseases website, “In 1993 Dr. Rueben Matalon discovered the gene. Gene: Often referred to as the “unit of heredity.” A gene is composed of a sequence of DNA required to produce a functional protein that causes Canavan from tissues provided by several Canavan families. This discovery led to carrier screening and prenatal testing for the disease” (9). “The Canavan Disease” is not the only term used for this particular disease. Names like, “ACY2 deficiency”, “Aminoacylase 2 deficiency”, “Aspa deficiency”, Aspartoacylase deficiency”, “Asp deficiency”, “Canavan-Van Bogaert-Bertrand disease”, “Leukodystrophy, spongiform”, “Spongy degeneration of central nervous system”, “Spongy degeneration of the brain”, “Spongy degeneration of white matter in infancy”, “Van Bogaert-Bertrand syndrome” or “Von Bogaert-Bertrand disease”(4).
What is the Canavan Disease? Common in which race and the chances? The Canavan Disease is an inherited disease that causes ongoing damage to the nerve cells in the brain. Quoted by the National Institute of Neurological Disorders and Stroke, “Canavan disease is a gene-linked neurological disorder in which the brain degenerates into spongy tissue riddled with microscopic fluid-filled spaces. Canavan disease has been classified as one of a group of genetic disorders known as the leukodystrophies but--unlike most leukodystrophies. Recent research has indicated that the cells in the brain responsible for making myelin sheaths, known as oligodendrocytes, cannot properly complete this critical developmental task. Myelin sheaths are the fatty covering that act as insulators around nerve fibers in the brain, as well as providing nutritional support for nerve cells. In Canavan disease, many oligodendrocytes do not mature and instead die, leaving nerve cell projections known as axons vulnerable and unable to properly function. Canavan disease is caused by mutation in the gene for an enzyme called aspartoacylase, which acts to break down the concentrated brain chemical known as N-acetyl-aspartate” (3). Signs and symptoms are discovered usually from when the infant is 3 to 5 months old by “detecting lack of enzymeaspartoacylase in skin cells or by genetic testing of the gene for Canavan disease in blood” (1). This particular disease is common in the Ashkenazi Jewish Community with a 1 out of 38 ratio and a 1 in 50,000 in the general population(1). This disease is also described to be common in a couple other countries too by the Canavan disease website, “Canavan Disease is quite prevalent among Semitic cultures; such as, Saudi Arabians and Ashkenazi Jews. When both the parents have the faulty gene, the child has a 25 % chance of being afflicted by the disease. Disease frequency that has been demonstrated is one in 5,000 Ashkenazi Jews; while, the carrier frequency seen is one in thirty eight Ashkenazi Jews” (7).

Side effects? Life Span? What tests could be taken to ensure you’re infected? This disease creates a big impact for those who have inherited it since it really reduces their lifespans as well as ongoing suffering in the form of symptoms such as, abnormal posture, Backflow of food, Feeding problems, Increasing head size, Irritability, Head lag, Poor muscle tone, Poor visual tracking or blindness, Seizures, Severe mental retardation and Swallowing difficulties (1). The