Clinical epidemiology of skeletal dysplasias in South America

• Published in: American journal of medical genetics. Part A 2012-05, Vol.158A (5), p.1038-1045
• Main Authors: Barbosa-Buck, Cecília O., Orioli, Iêda M., da Graça Dutra, Maria, Lopez-Camelo, Jorge, Castilla, Eduardo E., Cavalcanti, Denise P.
• Format: Article
• Language: English
• Subjects: achondroplasia; Biological and medical sciences; Case-Control Studies; Consanguinity; Diseases of the osteoarticular system; epidemiology; Humans; Malformations and congenital and or hereditary diseases involving bones. Joint deformations; Medical genetics; Medical sciences; osteochondrodysplasias; Osteochondrodysplasias - diagnosis; Osteochondrodysplasias - epidemiology; Osteochondrodysplasias - etiology; Osteochondrodysplasias - mortality; osteogenesis imperfecta; Paternal Age; Prevalence; Risk Factors; South America - epidemiology; thanatophoric dysplasia
• ISSN: 1552-4825; 1552-4833
• DOI: 10.1002/ajmg.a.35246

Currently accepted birth prevalence for osteochondrodysplasias (OCD) of about 2/10,000 is based on few studies from small series of cases. We conducted a study based on more than 1.5 million births. OCD cases were detected from 1,544,496 births occurring and examined in 132 hospitals of ECLAMC (Latin American Collaborative Study of Congenital Malformations) between 2000 and 2007. Cases were detected and registered according to a pre‐established protocol, and then ranked in four diagnostic evidence levels (DEL), according to available documentation. For the analysis of risk factors, a healthy control sample born in the same period was used. OCD was diagnosed in 492 newborns, resulting in a prevalence per 10,000 of 3.2 (95% CI: 2.9–3.5). Perinatal lethality (stillbirths plus early neonatal deaths) occurred in 50% of cases. Prenatal ultrasound diagnosis was made in 73% of cases (n = 359). Among 211 cases from the best documented group (DEL‐1) and according to international classification, 33% of cases fit into the G‐25 (osteogenesis imperfecta), 29% in Group‐1 (FGFR3), and 8% in Group‐18 (Bent bones). The prevalence of the main OCD types were: OI—0.74 (0.61–0.89); thanatophoric dysplasia—0.47 (0.36–0.59); and achondroplasia—0.44 (0.33–0.55). Paternal age (31.2 ± 8.5), parity (2.6), and parental consanguinity rate (5.4%) were higher in cases than in controls (P