Hi welcome to health care magic.... I can understand your concern.... With consaguious marriage chance of spread of some genetic disease is there like....... -hemophila -thalasemia -colour blindness -autosomal recessive disease -x linked disease -few syndrome like down syndrome etc.... For that you both should have done your electrophoresis HPLC and genetics study for that.... It is better to consult physician and get complete physical examination and accordingly investigation ..... It is better to avoid consaguious marriage but if you are planning kindly consult physician for complete discussion and examination... Take care