The jumping SHOX gene--crossover in the pseudoautosomal region resulting in unusual inheritance of Leri-Weill dyschondrosteosis.

CONTEXT

During meiosis I, the recombination frequency in the pseudoautosomal region on Xp and Yp (PAR1) in males is very high. As a result, mutated genes located within the PAR1 region can be transferred from the Y-chromosome to the X-chromosome and vice versa.

PATIENTS

Here we describe three families with SHOX abnormalities resulting in Leri-Weill dyschondrosteosis or Langer mesomelic dysplasia.

RESULTS

In about half of the segregations investigated, a transfer of the SHOX abnormality to the alternate sex chromosome was demonstrated.

CONCLUSIONS

Patients with an abnormality of the SHOX gene should receive genetic counseling as to the likelihood that they may transmit the mutation or deletion to a son as well as to a daughter.