Few regions of the world have a more varied physiography or a richer ethnic, religious, social, and cultural mix than the Arab world. As a consequence, Arabs are genetically diverse despite their linguistic and religious cohesion. High but variable rates of inbreeding prevail in all Arab countries with numerous examples of isolates among them. These include some Bedouin groups, Nubians, Druze, Jews, and others. Arab populations have high frequencies of autosomal recessive disorders, homozygosity of autosomal dominant and X-linked traits, and a wealth of new syndromes and variants, the majority of which are autosomal recessive. Genetic disorders that cause major health problems include hemoglobinopathies, neurogenetic disorders, inherited metabolic diseases, and inborn error of morphogenesis. Because of their characteristically high prevalence, some of these disorders are considered markers for Arab populations. This book presents the unique profile of genetic disorders and variants in Arabs. In addition, it describes their unusual demographic pattern including fertility rates and other population dimensions, family structure, magnitude and effects of consanguineous marriages and indicators of health and disease. Genetic counseling and the distinctive cultural and religious attitudes towards various genetic issues are also presented. Disorders that have increased tribal occurrences or are limited to large kindreds, as well as small geographic or religious isolates, are highlighted to facilitate their recognition, study, and management.