Recurrent dislocation of binocular crystal lenses in a patient with cystathionine beta-synthase deficiency

Background: Ectopia lentis is the common ocular manifestation of homocystinuria resulting from cystathionine beta-synthase (CBS) deficiency which has a high risk of thromboembolic complications. Case presentation: The present study reports the case of a teenager with recurrent lens dislocation and glaucoma. He was diagnosed with CBS deficiency according to a high level of serum homocysteine and compound heterozygous mutations at two different positions on the CBS gene. Antiglaucoma eyedrops and a mydriatic successfully controlled the intraocular pressure, while oral pyridoxine and betaine uptake lowered the serum homocysteine level effectively. Conclusions: Children with CBS deficiency may suffer from ectopia lentis, glaucoma and/or amblyopia. We firstly discovered a new mutation of CBS c. 697 T > G which had not been reported before. The patient was pyridoxine responsive and well controlled by medicine.