Atypical RPE-Pigmentation in Prader-Willi Syndrome

Introduction

Prader-Willi syndrome (PWS, OMIM 176 270) is a complex genetic disease with hypothalamic dysfunction arising from lack of expression, mutations, or other defects of paternally inherited imprinted genes on the proximal part of the long arm of chromosome 15 (q11–q13). The incidence at birth is approximately 1:25 000 [7] [10] [18]. Typical clinical signs are neonatal muscle hypotonia, hyperphagia beginning in year 2, central obesity, short stature, hypogonadism and genital hypoplasia, developmental delay, mental retardation, learning disabilities, characteristic facial features (narrow bifrontal diameter, almond-shaped palpebral fissures, thin upper lip and down-turned mouth), and many other minor clinical signs. Frequently reported ophthalmological findings in patients with PWS are myopia, astigmatism, strabismus and ocular hypopigmentation [3] [5] [8] [9] [15] [19].

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