Background: Clefts of the lip and palate are one of the most common congenital birth anomalies. Genetic factors play a great role in the etiology of them and the high percentage of the consanguineous marriage of the parents of the affected persons is one of the reasons. These defects not only make abnormal changes on appearance of the neonate, but also make a lot of stress and psychological problems for the patients and their families. Study on the prevalence of clefts, their risk factors and also genetic counseling for affected persons and their families can be a guideline for general population and probably reduce these anomalies over the generations.
Methods: Patients referred to the Department of Genetics, Imam Khomeini Hospital, Tehran, Iran were studied. A total of 7374 pedigrees of all the patients admitted to the Department, were studied during 2002-2005 and 99 pedigrees with the patients with cleft lip± palate or isolated cleft palate were separated. The total number of cases among these 99 pedigrees was 136. The effects of consanguineous marriage, positive family history and sex were investigated among cases.
Results: 70.8% of patients with syndromic clefts and 58.7% of patients with nonsyndromic CL±P had parents with consanguineous marriage. In addition 44.4% of patients with nonsyndromic CL±P had positive family history.
Conclusion: In our population prevalence of nonsyndromic CL±P was estimated to be 7 in 1000 (with 95% Confidence Interval was between 5 & 9) and prevalence of nonsyndromic CP was about 3.1 in 1000 (with 95% Confidence Interval was between 1.8 & 4.4). Consanguineous marriage of parents seems to have a significant role (p=0.02) on prevalence of the clefts.