Genetic Counseling for Couples Who are First Cousins

  • Lewis B. Holmes


It is general knowledge that parents should not be related to each other. This is based in part on hearsay information which suggests that related parents are more likely than unrelated couples to have mentally retarded offspring. The legislatures in most states in the United States have passed laws which prohibit marriage between first cousins (1). Consanguinity is rare in the United States; less than 1 in 1,000 couples are first cousins. Yet, each year several couples who are first cousins come to our Genetics Clinic for information about their risks of having abnormal or handicapped children. These consultations have prompted us to review the data available for defining the magnitude of the risk faced by these couples. While several studies have been conducted on the effects of inbreeding (2), it is difficult to translate this data to information useful to these couples.


Genetic Counseling Recessive Gene Genetic Clinic Handicapped Child Mental Deficiency 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Farrow, M.G. and Juberg, R.C., Genetics and laws prohibiting marriage in the United States. J.A.M.A. 209: 534 (1969).CrossRefGoogle Scholar
  2. 2.
    Fräser, G.R. and Mayo, O., Genetical load in man, Humangenetik 23: 83 (1974).Google Scholar
  3. 3.
    Holmes, L.B,, Inborn errors of morphogenesis. A review of localized hereditary malformations. New Eng. J. Med. 291: 763 (1974).Google Scholar
  4. 4.
    Book, J.A., Genetical investigations in a North Swedish population. Ann. Hum. Genet. 21: 191 (1957).CrossRefGoogle Scholar
  5. 5.
    Neel, J.V., A study of major congenital defects in Japanese infants. Amer. J. Hum. Genet. 10: 398 (1958).Google Scholar

Copyright information

© Plenum Press, New York 1976

Authors and Affiliations

  • Lewis B. Holmes
    • 1
    • 2
  1. 1.Harvard Medical School and Genetics ClinicUSA
  2. 2.Massachusetts General HospitalBostonUSA

Personalised recommendations