Epidemiology of Syndromic Craniosynostosis in Children
Incidence and Prevalence
Apert syndrome: 1.5 per 100,000 per year. Apert syndrome was calculated to have a birth prevalence of approximately 15.5 in 1 million births and accounts for about 4.5% of all cases of craniosynostosis. The study of Cohen et al. suggests that the birth prevalence of Apert syndrome is fairly uniform in different populations (17).
Crouzon syndrome: 1.5 per 100,000 per year. Crouzon syndrome was similarly estimated to have a birth prevalence of 15.5 in 1,000,000 (n=11) in a study by Martínez-Frías et al. (18).
Muenke syndrome: 1 per 30,000 per year, accounting for 8% of craniosynostosis (28).
Provisionally unique pattern syndrome: A one-of-a-kind syndrome to a particular observer at a particular point in time.
Recurrent pattern syndromes: A similar or identical set of anomalies in two or more unrelated patients. The etiology remains unknown at this stage, and the validity increases with the number of anomalies found and with the more patients recognized as having the syndrome.
Pedigree syndrome: A known genesis on the basis of pedigree evidence alone, the basic defect itself remains undefined, e.g., Carpenter syndrome.
Biochemical defect syndrome: In these cases a specific enzymatic defect has been described, e.g., Hurler syndrome.
Environmentally induced disorder: These are due to a causative teratogen, e.g., hydantoin.
Relationships to Other Disease States and Syndromes
1% of live births have syndromes: Approximately 1% of all newborns have multiple anomalies or syndromes, but only 40% of these can be diagnosed as having specific, recognized syndromes. Anomalies occur with various frequencies in different syndromes, and syndrome diagnosis is therefore not made from one anomaly but from the overall pattern of anomalies.