Epidemiology of isolated preaxial polydactyly type I: Data from the Polish Registry of Congenital Malformations (PRCM)
1 Chair and Department of Medical Genetics, Poznan University of Medical Sciences, Poznan, Poland
2 Department of Preventive Medicine, Poznan University of Medical Sciences, Poznan, Poland
3 Department of Computer Science and Statistics, Poznan University of Medical Sciences, Poznan, Poland
4 Chair and Department of Biology and Genetics, Medical University of Gdansk, Gdansk, Poland
5 Department of Neonatology and Neonatal Intensive Care, Medical University of Warsaw, Warsaw, Poland
6 Department of Obstetrics and Pathology of Pregnancy, Medical University of Lublin, Lublin, Poland
7 Regional Children’s Specialized Hospital, Olsztyn, Poland
BMC Pediatrics 2013, 13:26 doi:10.1186/1471-2431-13-26Published: 19 February 2013
Polydactyly represents a heterogeneous group of congenital hand and foot anomalies with variable clinical features and diverse etiology. Preaxial polydactyly type I (PPD1) is the most frequent form of preaxial polydactyly. The etiology of sporadic PPD1 remains largely unknown and the relative contribution of genetic and environmental factors is not clearly defined. The primary goals of this study are twofold: (1) to examine the epidemiology and clinical features of sporadic PPD1 in comparison to a healthy control group, and (2) to contrast the characteristics of sporadic PPD1 with familial forms of isolated polydactyly.
Among 2,530,349 live births registered in the Polish Registry of Congenital Malformations (PRCM), we identified 459 children with isolated sporadic PPD1 and 353 children with familial polydactyly, including 57 children with familial PPD1.
In comparison with the matched group of 303 controls, sporadic PPD1 cases had significantly lower birth order (P = 0.01) and birthweight (P < 0.0001). Similarly, when compared to familial cases of polydactyly, lower birth order (P = 0.047) and lower birthweight (P < 0.0001) were characteristic of sporadic PPD1 cases. Moreover, our analyses suggested several additional risk factors for sporadic PPD1, including lower paternal education levels (P = 0.01), upper respiratory tract infections during the first trimester of pregnancy (P = 0.049), and maternal history of epilepsy (P = 0.01).
In summary, our study provides support to the hypothesis that non-genetic factors play an important role in the etiology of non-familiar PPD1.