RESUMEN
Too much diversity and ever increasing number of genetic disorders appear as a big challenge in coming future. One of the main sources of genetic disorders is the consanguineous marriages which are, unfortunately very common in our society. In order to prepare ourselves to accept the challenge, the first step is to get complete information of their prevalence and their risk factors. The study was made during 2003-2007 in Tabriz city of Iran. We selected 6000 families and a complete data was obtained on a questionnaire comprised of information regarding marital ages, number of pregnancies, type of delivery, ratio of consanguineous and non consanguineous marriages jobs of parents... etc and their effect on child malformations. Consanguineous marriages of all types were related with increased congenital malformations [with ratio 43/1000 for consanguineous marriages and for non consanguineous marriages 28/1000]. Mother age less than 18 and more than 35 particularly was accompanied with increased malformations while education of mother came out to be inversely related to congenital malformation. Increased stillbirths, consanguineous marriage and malformations, especially of musculoskeletal system require new planning on national level to control and aware people of the consequences of consanguineous marriages