Clinical evidence suggests that a moiety of patients with low back syndrome refractory to conventional treatment may embody a pleiotropic expression of Marfan-like pathology of support tissue. Individuals in the suspect group display a triad of clinical findings including refractory low back syndrome, certain dural ectasias, and a susceptibility to protracted reactions after lumbar puncture. Certain stigmata found in these patients and their families are among those commonly seen in Marfan's disease. The concept, if valid, has important implications affecting therapeutic choices and may offer insights into unexplained failures. The finding of significant family involvement strengthens the possibility of a heritable substratum for this category of low back disease.