Pseudoautosomal Inheritance

Transmission Patterns of Pseudoautosomal inheritance

Pseudoautosomal inheritance describes the inheritance pattern seen with genes in the pseudoautosomal region of the X and Y chromosome that can exchange regularly between the two sex chromosomes.

Alleles for genes in the pseudoautosomal region can show male-to-male transmission, and therefore mimic autosomal inheritance, because they can cross over from the X to the Y during male gametogenesis and be passed on from a father to his male offspring.

Dyschondrosteosis, a dominantly inherited skeletal dysplasia of the forearm, is an example of a pseudoautosomal condition inherited in a dominant manner.

A greater prevalence of the disease was seen in females as compared with males, suggesting an X-linked dominant disorder, but the presence of male-to-male transmission clearly ruled out strict X-linked inheritance Opens in new window.

Mutations Opens in new window in the SHOX gene encoding a homeodomain-containing transcription factor have been found responsible for this condition. SHOX is located in the pseudoautosomal region on Xp and Yp and escapes X inactivation.

  1. Thompson & Thompson Genetics in Medicine E-Book By Robert L. Nussbaum, Roderick R. McInnes, Huntington F Willard
  2. Maternal, Fetal, & Neonatal Physiology4: Maternal, Fetal, & Neonatal Physiology By Susan Tucker Blackburn