Heterogeneity

In genetics, heterogeneity is the phenomenon that the same trait ( phenotype ) can be caused by different genes . Diseases that are caused heterogeneously, i.e. which can be traced back to mutations in different genes, are for example albinism and hereditary deafness .

In the case of heterogeneously caused diseases, even if the disease-causing alleles are recessive , children of two sick parents can be phenotypically healthy. For example, if disease-causing alleles (a and b) occur in two genes (A and B), an affected father with the genotype [AAbb] and an affected mother with the genotype [aaBB] can father a healthy child with the genotype [AaBb] .

Heterogeneity can make research into the causes of hereditary diseases much more difficult because, in addition to the occurrence of various alleles and environmental factors, it contributes to variations in the appearance of a disease.

literature

• Regine Witkowski, Otto Prokop , E. Ullrich: Lexicon of syndromes and malformations: causes, genetics, risks . 7th edition. Springer, 2003, ISBN 978-3-540-44305-6 , pp. 9-12 .