While not precisely known, it is estimated that the general rate of incidence, according to Bergsma, for<unk>  syndrome is 0.02 per 10,000 births. According to another study done six years later, the incidence rate could vary from 0.07 to 0.7 per 10,000 births. This syndrome is a Finnish heritage disease. Its frequency is much higher in Finland, where the incidence is as high as 1.1 per 10,000 births. It is estimated that<unk>  syndrome accounts for 5% of all neural tube defects there. The Leicestershire Perinatal Mortality Survey for the years 1976 to 1982 had found high incidences of<unk>  syndrome in Gujarati Indian immigrants.
Meckel–Gruber syndrome
Seckel syndrome
Laurence–Moon syndrome
Silver–Russell syndrome
Klüver–Bucy syndrome
Klippel–Feil syndrome
Koolen–De Vries syndrome
Landau–Kleffner syndrome