Developmental disability is an impairment that must be severe enough to cause significant limitations and occurs during a person’s early stages in life, from conception to the age of 20 years old. (Graziano, A. (2002). There are several factors that can contribute to a person having a developmental disability. A great example of one is genetics. The genes that are passed down from parents can play a role in a person having a developmental disability. Down syndrome also known as trisomy 21 is a genetic disorder that is caused by genetic chromosome 21. This disorder causes developmental and intellectual delays. (Graziano, A. (2002). This disorder is permanent and will affect the individual in many ways throughout their entire life. “There are 13.75 million people of all ages in the United States that have developmental disabilities.” (Graziano, A. (2002 pg. 34). My opinion which is based off the text and articles I read that there are probably just as many developmental disabilities that are caused by genetics as well as can be attributed by the environment. There are many disorders and diseases that are acquired from both the environment and genetics. Fetal alcohol syndrome is a great example of a developmental disability/disorder that is induced by the environment. Fetal alcohol syndrome occurs with women who consume alcohol during their pregnancy. This disorder can be mild or severe and can cause physical and mental birth defects. (Graziano, A. (2002). This is a very preventable environmentally caused disorder.”Developmental Psychopathology is the study of psychological problems of children and youth.” (Graziano, A. (2002 pg. 25). There are many children that have a combination of a developmental disability coupled with a psychological disorder. Autism is a serious developmental disorder that impairs the ability to communicate and interact. Autism or autism spectrum disorders is a great example of a disorder that overlaps with both developmental disabilities and psychological disorders.