Eight new and five previously illustrated patients with Niikawa-Kuroki syndrome (NKS) are compared to those in the literature, providing data on 183 cases. Eight patients had disproportionate microcephaly and in one autopsied patient there was frontal lobe atrophy, focal polymicrogyria, and a hypoplastic fourth ventricle. The metacarpophalangeal pattern profiles of three Caucasian patients with NKS were similar to that of a prior case report, but those of two Hispanic patients were more variable. NKS was eliminated by follow-up in nine suspect cases, highlighting the diagnostic value of findings such as arched eyebrows, long palpebral fissures, flat nasal tip, and prominent finger pads. One patient suspected of having NKS had a very different metacarpophalangeal pattern profile, supporting its diagnostic utility in selected cases. Higher frequencies of neonatal complications, abnormal dentition, hypotonia, and microcephaly were noted in non-Asian patients with NKS, while a higher frequency of skeletal anomalies was seen in Japanese patients. Complications affecting cognitive, visual, hearing, cardiac, renal, skeletal, immune, and endocrinologic functions are translated into a program for preventive management. X chromosome anomalies are the most compelling of diverse genetic changes seen in NKS, and this report adds another case to several possible instances of vertical transmission. The 108 non-Asian patients now reported emphasize the worldwide significance of NKS recognition. Am. J.