People can have mental retardation, odd facial expressions, and happy personality {Angelman's syndrome} {Angelman syndrome} {happy puppet syndrome}.
Rare diseases {autism}| can involve abnormal development before 2.5 years old.
symptoms
Autistic children have stereotyped hand movements and facial grimaces. They withdraw from adults. They do not make friends with other children. They do not develop social responses or relationships. They have little eye contact. They do not adapt easily to new situations. They are obsessive. They strongly attach to favored objects. They cannot classify emotional responses. They cannot imagine others' mental states {mind blindness}. They have difficulty pretending.
biology
Autistic children typically have below-normal intelligence. Perhaps, bilateral hippocampal lesions, limbic-system and vestibular-nuclei abnormalities, brain injury, or chromosome-7 HOXA1-gene damage causes autism.
gender
Autism is more in boys than in girls.
Iodine lack or damaged thyroid gland can cause decreased thyroxin, fat appearance, and mental retardation {cretinism}|.
Enzyme deficiency causes inability to make phenylalanine into tyrosine and results in toxicity affecting gait and posture {phenylketonuria}| (PKU). Enzyme deficiency also causes inability to metabolize phenyl pyruvate, and excess blood phenyl pyruvate causes mental retardation. PKU affects one in 10,000 births. Diets low in phenylalanine can prevent PKU.
4-Medicine-Disease-Kinds-Organ-Nerve
Outline of Knowledge Database Home Page
Description of Outline of Knowledge Database
Date Modified: 2022.0225