Aicardi Syndrome is a disorder that generally only affects females (there have been two male cases documented in history, however these patients were documented as having an XXY genotype as opposed to an XY genotype). Those suffering form the condition are completely or partially lacking the corpus callosum- the structure that joins the two hemispheres of the brain.

The exact cause of aicardi syndrome is unknown, however some theories have suggested that the disorder may be associated with an abnormality on the X chromosome.

The disorder is extremely rare, with only five hundred known cases worldwide.

Adrenoleukodystrophy is a disorder that results in damage to the myelin sheath surrounding the nerve cells of the brain. Myelin sheaths are required for the effective travel of impulses through the nerves, thus their degradation prevents impulses being conducted, leading to increasing disability of a person. The condition is characterized by increased levels of saturated, very long chain fatty acids in the brain. The accumulation of these fatty acids occurs due to a deficiency in the enzyme that is required to break them down. As the most common form of adrenoleukodystrophy is a disorder of the X chromosome, it is more likely to affects males than females.

Androgen Insensitivity Syndrome is a disorder characterized by the body’s inability to respond to hormones (androgens) that direct male sexual development; this ultimately affects the sexual development of an individual.

People suffering from the disorder will have an XY genotype. In the case of a person not suffering from Androgen Insensitivity Syndrome their ability to respond to male hormone correctly would ensure the development of male characteristics; the body of a person with Androgen Insensitivity Syndrome will not respond correctly to male hormones, thus their body will take on female characteristics or will show both male and female characteristics (hermaphroditism).

Acid maltase deficiency is a disease characterized by the retention and consequent excessive accumulation of glycogen within cells in the body. Glycogen is a substance that is converted from sugars in food and stored in the body for used as energy. Acid maltase enzyme is required to break down glycogen when it is required for energy; people suffering from acid maltase deficiency are deficient in this enzyme, thus their bodies are unable to mobilize stored glucose, allowing it to accumulate within the cells of the body. The stores of glycogen will continue to build up within the muscle and will ultimately begin to cause muscle weakness and degeneration.