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Congenital glaucoma refers to a genetically heterogeneous group of distinctive clinical diseases characterised by increased intraocular pressure most often associated with increased corneal diameter, corneal oedema, and consequent visual impairment. Primary congenital glaucoma (PCG) is associated with a primary angle defect, whereas secondary congenital glaucoma is associated with a more generalised developmental anomaly of the anterior segment such as seen in Peters' anomaly. The inheritance of PCG is usually autosomal recessive. Peters' anomaly consists of corneal opacity, defects in the posterior structures of the cornea, and iridocorneal and/or keratolenticular adhesions, and it most frequently occurs sporadically.1Over 50% of subjects develop glaucoma in childhood. Numerous aetiologies have been proposed including chromosomal abnormalities, teratogens,1 and mutations in the eye developmental genes PAX6 2-4 and PITX2 .5 However, large subsets of Peters' anomaly cases are without molecular characterisation. Primary congenital glaucoma has been linked to chromosomes 1p36 (GLC3B) and 2p21 (GLC3A), but only the GLC3A gene has been identified. This gene, CYP1B1 , encodes a broadly expressed cytochrome P450 enzyme (P4501B1) whose natural substrate is unknown.6 7 It is proposed to be the major gene for disease causing mutations in primary congenital glaucoma.6-11 A variety of chain terminating and missense CYP1B1 mutations have been described.6-9 We report two novel mutations in CYP1B1 in a patient who had Peters' anomaly with secondary congenital glaucoma. The subject, a male of Native Indian (Mohawk)/French Canadian background, presented with a history of bilateral cloudy corneas and tearing since birth. Examination at 3 weeks of age showed bilateral corneal oedema with central corneal opacities, superficial pannus (corneal vascularisation), and iridocorneal adhesions with a well formed anterior chamber (fig 1, above). Iris was present for …