Usually the neurodevelopmental symptoms will decrease in later childhood.Phenylketonuria, also known as PKU, can induce neurodevelopmental problems and children with PKU require a strict diet to prevent intellectual disability and other disorders. In the maternal form of PKU, excessive maternal phenylalanine can be absorbed by the fetus even if the fetus has not inherited the disease. This can produce intellectual disability and other disorders. Nutrition
Nutrition disorders and nutritional deficits may cause neurodevelopmental disorders, such as spina bifida, and the rarely occurring anencephaly, both of which are neural tube defects with malformation and dysfunction of the nervous system and its supporting structures, leading to serious physical disability and emotional sequelae. The most common nutritional cause of neural tube defects is folic acid deficiency in the mother, a B vitamin usually found in fruits, vegetables, whole grains, and milk products. (Neural tube defects are also caused by medications and other environmental causes, many of which interfere with folate metabolism, thus they are considered to have multifactorial causes.) Another deficiency, iodine deficiency, produces a spectrum of neurodevelopmental disorders ranging from mild emotional disturbance to severe intellectual disability. (see also congenital iodine deficiency syndrome).Excesses in both maternal and infant diets may cause disorders as well, with foods or food supplements proving toxic in large amounts. For instance in 1973 K.L.
Fragile X syndrome was first described in 1943 by Martin and Bell, studying persons with family history of sex-linked "mental defects". Rett syndrome, another X-linked disorder, produces severe functional limitations. Williams syndrome is caused by small deletions of genetic material from chromosome 7. The most common recurrent Copy Number Variant disorder is 22q11.2 deletion syndrome (formerly DiGeorge or velocardiofacial syndrome), followed by Prader-Willi syndrome and Angelman syndrome. Immune dysfunction
Immune reactions during pregnancy, both maternal and of the developing child, may produce neurodevelopmental disorders. One typical immune reaction in infants and children is PANDAS, or Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infection. Another disorder is Sydenhams chorea, which results in more abnormal movements of the body and fewer psychological sequellae. Both are immune reactions against brain tissue that follow infection by Streptococcus bacteria. Susceptibility to these immune diseases may be genetically determined, so sometimes several family members may have one or both of them following an epidemic of Strep infection. Infectious diseases
Systemic infections can result in neurodevelopmental consequences, when they occur in infancy and childhood of humans, but would not be called a primary neurodevelopmental disorder. For example HIV Infections of the head and brain, like brain abscesses, meningitis or encephalitis have a high risk of causing neurodevelopmental problems and eventually a disorder. For example, measles can progress to subacute sclerosing panencephalitis.