Schwartz–Jampel syndrome (SJS) is a rare genetic disease caused by a mutation in the HSPG2 gene, which makes the protein perlecan, and causing osteochondrodysplasia associated with myotonia.
Relationships between the disease and perlecan deficiency have been studied.
Schwartz–Jampel syndrome Wikipedia
The syndrome was first described in 1962 by Oscar Schwartz and Robert Jampel.
In March 2013 there was media coverage on a 7-year-old boy with chronically tense muscles due to SJS and his three-legged pet dog. They became first-place winners of the 2013 Crufts Kennel Club's annual Friends for Life competition which "celebrates dogs that have truly earned the title of man’s best friend through bravery, support or companionship". The dog was also awarded The Braveheart Honour in the ceremony of The British Animal Honours in April 2013 (Haatchi the dog).