Clinical/epidemiological analysis of malformations.

To investigate the heterogeneity of congenital malformations, we analyzed the distribution of 14 selected anomalies among 11,421 children with isolated defects and with different patterns of multiple congenital anomalies (MCA). Our study showed a marked variability in the distribution of each of these malformations. For example, although anophthalmia/microphthalmia, cleft palate, and limb deficiency were observed in all etiological categories of syndromes, no case with anencephaly was identified among the 1,244 children with different syndromes. Diaphragmatic hernia, esophageal atresia +/- tracheoesophageal fistula, and gastroschisis were not found in any monogenic syndrome in this sample. These observations may be of help to the clinician in the evaluation of individual children with MCA.