"Complete" trisomy 5p; de novo translocation t(2;5)(q36;p11) with isochromosome 5p. Case report and review of the literature.

A case of complete trisomy 5p due to a de novo translocation t(2;5)(q36;p11) with an isochromosome 5p is described. Complete trisomy 5p has been reported only once (Brimblecombe et al., 1977). The confusing literature relating to partial trisomy 5p is reviewed. Comparison of our case with the patients reported by Brimblecombe et al. (1977) and by Opitz and Patau (1975) is suggestive for a distinct clinical syndrome if (almost) the complete short arm of chromosome 5 is present in a trisomic state. Unfortunately the clinical findings in the case of Brimblecombe (1966, 1977) are poorly documented. The main features of this syndrome are: macrocephaly, psychomotor retardation, hypotonia, postnatal growth failure, tracheobronchial involvement, mongoloid slant of the eyes, epicanthus, low-set ears, depressed nasal bridge, short first toe, and seizures.