Chromosomal genetic disorders occur when chromosomes are partially or completely missing, altered or duplicated. An example of a chromosomal genetic disorder is Down syndrome. Down syndrome is the result of an extra, third copy of chromosome 21 being present in a person.
Angelman syndrome (AS) is a genetic disorder that mainly affects the nervous system. Symptoms include a small head and a specific facial appearance, severe intellectual disability, developmental disability, speech problems, balance and movement problems, seizures, and sleep problems.
Fragile X syndrome (FXS) is an inherited genetic disease passed down from parents to children that causes intellectual and developmental disabilities. It’s also known as Martin-Bell syndrome. FXS is the most common hereditary cause of mental disability in boys. It affects 1 in 4,000 boys.
Neurofibromatosis type 1 is a condition characterized by changes in skin coloring (pigmentation) and the growth of tumors along nerves in the skin, brain, and other parts of the body. The signs and symptoms of this condition vary widely among affected people.