In this article we will discuss about the examples of pedigree pattern of autosomal and sex chromosomal genetic diseases.
1. Pedigree pattern of an autosomal dominant trait. Note the vertical pattern of inheritance. Solid squares and circles indicating the affected males and females while hollow squares and circles are unaffected males and females.
2. Pedigree patterns of an autosomal recessive trait. Note the horizontal pattern of inheritance. Double line marriage figure indicates consanguineous mating.
3. Pedigree pattern of and X-linked recessive trait (Fig. A). Note the oblique pattern of inheritance. Hollow circle with middle dot indicates carrier females. In this diagram it is observed that an affected female can result from the mating of an affected male and a carrier female (Fig. B); and similarly an affected male mating with a normal non-carrier female has all normal sons and all carrier daughters (Fig. C).
4. Pedigree pattern of an X-linked dominant trait.
5. Pedigree pattern of an X-linked dominant trait lethal in the hemizygous male. Small solid circles indicate abortions.
