title: Consanguinity and genetic diseases in North Africa and immigrants to Europe.
abstract: Endemic diseases are caused by environmental and genetic factors. While in this special issue several chapters deal with environmental factors, including infections, the present focus is on genetic causes of disease clustering due to inbreeding and recessive disease mechanisms. Consanguinity is implying sharing of genetic heritage because of marriage between close relatives originating from a common ancestor. With limited natural selection, recessive genes may become more frequent in an inbred compared with an outbred population. Consanguinity is common in North Africa (NA), and the estimates range from 40 to 49% of all marriages in Tunisia and 29-33% in Morocco. As a consequence, recessive disorders are common in the NA region, and we give some examples. Thalassaemia and sickle cell disease/anaemia constitute the most common inherited recessive disorders globally and they are common in NA, but with immigration they have spread to Europe and to other parts of the world. Another example is familial Mediterranean fever, which is common in the Eastern Mediterranean area. With immigrantion from that area to Sweden, it has become the most common hereditary autoinflammatory disease in that country, and there is no evidence that any native Swede would have been diagnosed with this disease. The examples discussed in this chapter show that the historic movement of populations and current immigration are influencing the concept of 'endemic' disease.
authors.affiliation: 1 Community Medicine Department, Ain Shams University, Cairo, Egypt wagidaanwar@gmail.com.
authors.forename: Wagida A
authors.initials: WA
authors.lastname: Anwar
authors.affiliation: 2 Pasteur Institute of Morocco, Casablanca, Morocco.
authors.forename: Meriem
authors.initials: M
authors.lastname: Khyatti
authors.affiliation: 3 Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany4 Center for Primary Health Care Research, Lund University, 205 02, Malmö, Sweden.
authors.forename: Kari
authors.initials: K
authors.lastname: Hemminki
mesh_terms: D000352:Africa, Northern / Q000208:ethnology; D003241:Consanguinity; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005060:Europe / Q000453:epidemiology; D030342:Genetic Diseases, Inborn / Q000453:epidemiology* / Q000208:ethnology; D006801:Humans; D008393:Marriage / Q000706:statistics & numerical data