Rud Syndrome: Congenital Ichthyosis, Hypogonadism, Mental Retardation, Retinitis Pigmentosa and Hypertrophic Polyneuropathy

 

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Abstract

Rud syndrome consists in the association of oligophrenia and hypogonadism with congenital ichthyosis; in the majority of cases, epilepsy, short stature or delayed in growth are also found. We described a child with such a syndrome. In addition to the classical findings, the patient had retinitis pigmentosa and hypertrophic polyneuropathy. Histological studies, including ultrastructural findings of a sural nerve biopsy, showed signs of a chronic demyelinative neuropathy with onion bulb formation. The world literature was reviewed and only nine other cases fulfilled our criteria for inclusion in Rud syndrome. This case represents the one with the most extensive neurological involvement ever reported.

Among the various types of neuroectodermal dysplasia, Rud syndrome is characterized by the triad of congenital ichthyosis, mental retardation and hypogonadism (Rud 1927). In most cases, epilepsy is also present, and either a delay in growth or shortness of stature. In addition, other abnormalities have occasionally been described: retinitis pigmentosa (Stewart 1939), neurosensory deafness (York-Moore and Rundle 1962), and polyneuritis (Rud 1927, Ruiz Maldonado et al 1975).

Nine well documented cases (Rud 1927, van Bogaert 1935, Stewart 1939, MacGillivray 1954, York-Moore and Rundle 1962, Nissley and Thomas 1971, Ruiz Maldonado et al 1975, Toribio et al 1976) fulfill the criteria for inclusion in this syndrome. Many other cases (Rud 1929, Ewing 1956, Benincasa-Stagni et al 1960, Wright 1961, Kissel et al 1973, Vittori and Bourgeois 1973) are often quoted as Rud syndrome, but because they lack cardinal features essential for diagnosis, (whether from incomplete investigation or from confusion with other forms of neuroectodermal dysplasia) they have to be rejected. A great deal of misconception still exists about this rare entity. It is explained in part by uncertainty in applying criteria, especially since the second of Rud's two original cases (Rud 1929) had only congenital ichthyosis and infantilism without indication of mental or neurological impairment.

We now present an additional case which, in addition to the cardinal features of this syndrome, presented a striking retinitis pigmentosa, increased CSF protein and hypertrophic polyneuropathy. No other case with such extensive neurological involvement has been described so far. It probably represents the full expression of the syndrome and hence, will help to better delineate it from other poorly defined forms of neuroectodermal dysplasia.