Retinal dysfunction and high myopia in association with 48,XXYY syndrome

48,XXYY syndrome was first described in 1964 and approximately 100 cases have been reported in the literature. We report a case of 48,XXYY syndrome associated with high myopia and retinal dysfunction.

Case report.

A 28-year-old man was referred with progressive deterioration of visual acuity (VA) bilaterally during the previous 4-5 years. Physical examination revealed tall stature, large feet and irregular teeth. Refraction revealed high myopia with VA 6/60 bilaterally. Fundoscopy revealed a normal vitreous, lightly pigmented retinal pigment epithelium and choroid but no bone spicules or overt signs of retinal degeneration. His visual fields were constricted. Electrodiagnostic testing revealed bilateral generalised retinal dysfunction with severe macular involvement. During follow-up, his ophthalmic examination did not exhibit significant changes while VA was gradually deteriorating. Eight years after presentation, VA was 3/60 bilaterally; electrophysiological testing showed no further change. At that stage, his parents consented for DNA analysis in order to determine the cause of retinal dysfunction. Chromosomal analysis revealed an abnormal male karyotype with two X chromosomes and two Y chromosomes consistent with 48,XXYY syndrome.

The present report is the first to describe retinal dysfunction and high myopia with 48,XXYY syndrome. The severe macular and generalised retinal dysfunction in this case are not those associated with myopia and are in keeping with a primary retinal dysfunction. A coincidental finding cannot be excluded, but ERGs have not previously been reported in 48,XXYY syndrome, and retinal dystrophy may be a previously undiagnosed component of this syndrome.