Wong H B
Department of Paediatrics, School of Postgraduate Medical Studies, National University of Singapore.
Ann Acad Med Singap. 1988 Jul;17(3):305-10.
The embryology of the normal lip and palate and the abnormal development of these structures causing cleft lip (CL) and cleft palate (CP) are discussed. As the development of the lip and palate is not dependent on a single factor but on many factors, it is understandable that CL and CP may occur as a result of abnormalities of genes of large mutant effect (i.e. Mendelian mutant genes), or due to chromosomal anomalies. However, these 2 causes are relatively uncommon and the commonest mode of production is dependent on both genetic and environmental factors. The mechanisms whereby these 3 groups may produce CL and CP will be discussed. Since the modes of inheritance differ in the 3 groups, it is important to discover which group a particular patient belongs to. The genetic load is high in the Mendelian group, is low usually in those due to chromosome disorders, and may be low or high in the last group depending on the polygenes as well as environmental factors. In this last group, empiric risk figures may be calculated for future offspring to be affected. The prenatal diagnosis of CL and CP is also discussed.
本文讨论了正常唇和腭的胚胎学以及导致唇裂（CL）和腭裂（CP）的这些结构的异常发育。由于唇和腭的发育并非取决于单一因素，而是受多种因素影响，因此唇裂和腭裂可能是由大突变效应基因（即孟德尔突变基因）异常或染色体异常引起的，这是可以理解的。然而，这两种原因相对少见，最常见的发病方式取决于遗传和环境因素。将讨论这三组因素产生唇裂和腭裂的机制。由于这三组的遗传方式不同，确定特定患者属于哪一组很重要。孟德尔组的遗传负荷较高，染色体疾病导致的通常较低，最后一组的遗传负荷可能低也可能高，这取决于多基因以及环境因素。在最后一组中，可以计算未来后代受影响的经验风险数字。本文还讨论了唇裂和腭裂的产前诊断。
