Preferential associations between oral clefts and other major congenital anomalies.

OBJECTIVES: To identify preferential associations between oral clefts (CL = cleft lip only, CLP = cleft lip with cleft palate, CP = cleft palate) and nonoral cleft anomalies, to interpret them on clinical grounds, and, based on the patterns of associated defects, to establish whether CL and CLP are different conditions. DESIGN AND SETTINGS: Included were 1416 cleft cases (CL = 131, CLP = 565, CP = 720), among 8304 live- and stillborn infants with multiple congenital anomalies, from 6,559,028 births reported to the International Clearinghouse for Birth Defects Surveillance and Research by 15 registries between 1994 and 2004. Rates of associated anomalies were established, and multinomial logistic regressions applied to identify significant associations. RESULTS: Positive associations with clefts were observed for only a few defects, among which anencephaly, encephaloceles, club feet, and ear anomalies were the most outstanding. Anomalies negatively associated with clefts included congenital heart defects, VATER complex (vertebral defects, imperforate anus, tracheoesophageal fistula, and radial and renal dysplasia), and spina bifida. CONCLUSION: The strong association between all types of clefts and anencephaly seems to be attributable to cases with disruptions; the association between CP and club feet seems to be attributable to conditions with fetal akinesia. Some negative associations may depend on methodologic factors, while others, such as clefts with VATER components or clefts with spina bifida, may depend on biological factors. The different patterns of defects associated with CL and CLP, indicating different underlying mechanisms, suggest that CL and CLP reflect more than just variable degrees of severity, and that distinct pathways might be involved.

Gastroschisis and associated defects: an international study.

Our objective was to evaluate the frequency and type of malformations associated with gastroschisis in a large pool of international data, to identify malformation patterns, and to evaluate the role of maternal age in non-isolated cases. Case-by-case information from 24 registries, all members of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), were evaluated. After the exclusion of other abdominal wall defects cases were classified as: (a) isolated; (b) recognizable syndrome, chromosomal or not; (c) multiple congenital anomalies (MCA). Our results showed that out of 3,322 total cases 469 non-isolated cases were registered (14.1%): 41 chromosomal syndromes, 24 other syndromes, and 404 MCA. Among MCA four groups of anomalies were most frequent: CNS (4.5%), cardio-vascular (2.5%), limb (2.2%), and kidney anomalies (1.9%). No similar patterns emerged except two patterns resembling limb-body wall complex and OEIS. In both of them the gastroschisis could be however misclassified. Chromosomal trisomies and possibly non-syndromic MCA are associated with an older maternal age more than isolated cases. On consideration of our data and the most valid studies published in the literature, the best estimate of the proportion of gastroschisis associated with major unrelated defects is about 10%, with a few cases associated to recognizable syndromes. Recognized syndromes with gastroschisis seem to be so exceptional that the well documented and validated cases are worth being published as interesting case report. An appropriate case definition in etiological studies should include only isolated gastroschisis after an appropriate definition of isolated and non-isolated cases and a thorough case-by-case review.