Fetal Alcohol Spectrum Disorders (FASD) can exhibit a combination of the above, most commonly ADHD, because of this, FASD is usually under-diagnosed, yet it is estimated that about 1 in 20 people may be affected. Currently being researched
There are neurodevelopmental research projects examining potential new classifications of disorders including:

Nonverbal learning disorder (NLD or NVLD), a neurodevelopmental disorder thought to be linked to white matter in the right hemisphere of the brain and generally considered to include (a) low visuospatial intelligence; (b) discrepancy between verbal and visuospatial intelligence; (c) visuoconstructive and fine-motor coordination skills; (d) visuospatial memory tasks; (e) reading better than mathematical achievement; and (f) socioemotional skills. While Nonverbal learning disorder is not categorized in the ICD or DSM as an discrete classification, "the majority of researchers and clinicians agree that the profile of NLD clearly exists (but see Spreen, 2011, for an exception), but they disagree on the need for a specific clinical category and on the criteria for its identification." Presentation
Consequences
The multitude of neurodevelopmental disorders span a wide range of associated symptoms and severity, resulting in different degrees of mental, emotional, physical, and economic consequences for individuals, and in turn families, social groups, and society. Causes
The development of the nervous system is tightly regulated and timed; it is influenced by both genetic programs and the environment. Any significant deviation from the normal developmental trajectory early in life can result in missing or abnormal neuronal architecture or connectivity.
Because of the temporal and spatial complexity of the developmental trajectory, there are many potential causes of neurodevelopmental disorders that may affect different areas of the nervous system at different times and ages. These range from social deprivation, genetic and metabolic diseases, immune disorders, infectious diseases, nutritional factors, physical trauma, and toxic and environmental factors. Some neurodevelopmental disorders, such as autism and other pervasive developmental disorders, are considered multifactorial syndromes which have many causes that converge to a more specific neurodevelopmental manifestation. Social deprivation
Deprivation from social and emotional care causes severe delays in brain and cognitive development. Studies with children growing up in Romanian orphanages during Nicolae Ceauşescus regime reveal profound effects of social deprivation and language deprivation on the developing brain. These effects are time-dependent. The longer children stayed in negligent institutional care, the greater the consequences. By contrast, adoption at an early age mitigated some of the effects of earlier institutionalization (abnormal psychology). Genetic disorders
A prominent example of a genetically determined neurodevelopmental disorder is Trisomy 21, also known as Down syndrome. This disorder usually results from an extra chromosome 21, although in uncommon instances it is related to other chromosomal abnormalities such as translocation of the genetic material. It is characterized by short stature, epicanthal (eyelid) folds, abnormal fingerprints, and palm prints, heart defects, poor muscle tone (delay of neurological development), and intellectual disabilities (delay of intellectual development).Less commonly known genetically determined neurodevelopmental disorders include Fragile X syndrome.