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.
Synovial osteochondromatosis (SOC) (synonyms include synovial chondromatosis, primary synovial chondromatosis, synovial chondrometaplasia) is a rare disease that creates a benign change or proliferation in the synovium or joint-lining tissue, which changes to form bone-forming cartilage. In most occurrences, there is only one joint affected, either the knee, the hip, or the elbow. Rarely involves the TMJ.The cause is unknown. In this condition, cartilaginous metaplasia takes place within the synovial membrane of the joint. Metaplastic synovium organizes into nodules. With minor trauma, nodules are shed as small bodies into the joint space. In some patients, the disease process may involve tendon sheaths and bursal sacs. Cartilaginous intra-articular bodies float freely within the synovial fluid, which they require for nutrition and growth. Progressive enlargement and ossification occur with time. If they remain free, they continue to grow larger and more calcified. In severe cases, they may occupy the entire joint space or penetrate to adjacent tissues. Also, they can deposit in the synovial lining, reestablish a blood supply, and become replaced by bone. On occasion, synovial reattachment can lead to complete reabsorption of the cartilage fragment. Signs and symptoms
Chronic, progressive pain and swelling of the affected joint are exacerbated by physical activity. Joint effusion and limited range of motion are common associated features. It affects primarily large joints, including knee (>50% of cases), elbow, hip, and shoulder. SOC is twice as common in men as women. Some patients have intra-articular bodies resting in stable positions within joint recesses or bursae.