In the course of a urine screening of patients with nontraumatic ectopia lentis or presumed Marfan syndrome, or both, 14 families, containing a total of 26 persons, with homocystinuria have been detected. Homocystinuria is an inborn error of metabolism inherited as an autosomal recessive, unlike the true Marfan syndrome that is inherited as a dominant.
Since homocystinuria have ectopia lentis and skeletal and vascular abnormalities, the Marfan syndrome is simulated. The eye lesions are indistinguishable from those of Marfan syndrome. Excessively long extremities, scoliosis, and deformity of the anterior chest occur as in the Marfan syndrome. Loose-jointedness is a less