| | Conditions Treatments | Genetic Disorders How many girls have prader willi syndrome? The prevalence of Prader-Willi syndrome is estimated to be 1 in 15,000 to 1 in 20,000 people, and it affects both males and females equally. Genetic Disorders - Related Articles How do you stop yourself from getting nightmares? Can SIDS occur while baby is held by parent? Low Vision Activities in Skilled Care Pros of Chewing Gum What Is a Kcal Versus a Cal? Nurse to Patient Ratio in a Nursing Home What are two examples of neurotransmitters?