The association of corneal opacity, microphthalmia, microcephaly, mental retardation, and generalized muscular spasticity with hyperglycinemia was presented for the first time by Balci and colleagues in 1974. After this report, some similar cases in the literature were referred to as Balci's syndrome. In this paper we describe a new case of Balci's syndrome, a 2.5-month-old female patient with corneal opacity, microphthalmia, microcephaly, mental retardation, and generalized muscular spacticity. All of these findings are acceptable as Balci's syndrome, and in addition she had congenital heart disease (ventricular septal defect) and renal anomalies. In this paper other syndromes associated with corneal opacity and mental retardation are discussed.