Schwartz Jampel syndrome is a disease of bone and muscle. Signs and symptoms may include muscle weakness and stiffness, abnormal bone development, joint contractures, short stature, small, fixed facial features, and eye abnormalities (some of which may impair vision). The range and severity of symptoms vary from case to case. It is caused by mutations in the HSPG2 gene which makes a protein called perlecan.
There is a more severe, distinct condition called Stuve-Wiedemann syndrome which is caused by mutations in the LIFR gene. At one time cases of Stuve-Wiedemann syndrome were referred to as Neonatal Schwartz Jampel syndrome type 2. Click on the link above to learn more about this syndrome. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.