Sex-specific, generic diseases can be avoided  Some parents are carriers of known sex-specific diseases. It is obviously in the child's interests that they don't have such a condition. Determining its gender can ensure that. Many families have predispositions towards certain common conditions that are more likely in one gender in another, and these can be avoided too. Nearly all neurodevelopmental diseases are either more common in one gender or more severe among one gender. Arthritis, heart disease and even lung cancer also seem to be influenced by a person's gender. Males disproportionately suffer from X chromosome problems because their body has no copy to fall back on 1 These range in nature from baldness and colour blindness to muscular dystrophy and haemophilia. Women are disproportionately affected by diseases of the immune system 2. Genetic modification is not the only technology available. The MicroSort technique uses a 'sperm-sifting' machine to detect the minute difference between y and double x chromosome-carrying sperm: no genetic harm results from its use. Over 1200 babies have been born using the technology 3.  1. Macnair, D. T. (2010, August). Fragile X Syndrome. Retrieved May 20, 2011, from BBC Health:  2. Doe, J. (2000, December 18). Immune System Disorders. Retrieved May 20, 2011, from Time:  3. Genetics and IVF Institute. (2008, January 1). Microsort. Retrieved May 20, 2011, from Genetics and IVF Institute: