Genetics the parents and the children very small. The

Genetics is the study of genes, genetic variation, and heredity in living organisms.There are several developmental disabilities that are definitely caused by genetic.  Dwarfism for example, is a genetic disability that has both the parents and the children very small.  The mother carries the dominant gene and her children at 50% at risk of getting the disease.Some developmental disabilities are not genetic and are due to other factors.An example of that is the Williams syndrome. WS is a genetic condition that is present at birth and can affect anyone. It is characterized by medical problems, including cardiovascular disease, developmental delays, and learning challenges. These often occur side by side with striking verbal abilities (Williams Syndrome association Jan, 2018).Another example of developmental disabilities is the Gerstmann syndrome, it is a rare neurological disorder that can occur as the result of a brain injury or as a developmental disorder. If someone have gerstmann syndrome have problems with left/right confusion, impaired arithmetic skills, inability to identify fingers and agraphia.Scientists are not sure about whether other developmental disabilities are genetic or not. They have been doing studies to figure out what causes these disabilities such as autism, bipolar, schizophrenia, and…. Developmental disability: a severe, permanent, physical or psychological impairment originating before age 22 and cause severe functional disruption (handicap) in person life. Developmental disabilities cause individuals living with a lot difficulties time in the life, especially independent living, learning, self-help and language.   By watching the video of Jay Giedd, M.D: Twins are the best way to address nature/nurture questions. Identical twins, or monozygotic, share almost one hundred percent of their DNA. And fraternal twins, or dizygotic, share out about fifty percent. So by seeing how much more alike the identical twins are than non-identical, we can get a sense for how much the DNA matters for brain or behavior or all kinds of different variables.  That if they’re not being expressed any younger it doesn’t matter if you’re identical or non-identical, because those genes aren’t doing anything. But whether its puberty or other unknown timing factors, when these genes then become expressed, those parts for the brain become more heritable. Most illnesses actually manifest during adolescence — psychosis, bipolar disorder, eating disorders, substance abuse, anxiety, panic attacks. So literally over fifty percent of mental illnesses when they happen occur during this adolescent period. https://www.youtube.com/watch?v=FCaLJN2d1zM