Complex sentence: Medical researchers at the University of Texas Southwestern Medical Center have speculated that it may be a form of neonatal progeroid syndrome (Wiedemann-Rautenstrauch syndrome), which does not affect Velásquez's healthy bones, organs, and teeth.
Split into simpler sentences: Medical researchers at the University of Texas Southwestern Medical Center have speculated that it may be a form of neonatal progeroid syndrome (Wiedemann-Rautenstrauch syndrome). Which does not affect Velásquez's healthy bones, organs, and teeth.