THE INV DUP(15) SYNDROME - A CLINICALLY RECOGNIZABLE SYNDROME WITH ALTERED BEHAVIOR, MENTAL-RETARDATION, AND EPILEPSY

The most common of the heterogeneous group of the extra structurally a bnormal chromosomes (ESACs) is the inv dup(15), whose presence results in tetrasomy 15p and partial tetrasomy 15q. Inv dup(15), containing t he Prader-Willi/Angelman syndrome (PWS/AS) region, are constantly asso ciated with phenotypic abnormalities and mental retardation. We report on four additional patients with inv dup(15), whose behavioral patter n, and neurologic and physical findings further delineate the phenotyp e of this neurogenetic syndrome. We also provide FISH analyses on chro mosomes of the observed ESACs and discuss the role of a number of gene s located within the tetrasomic region.