842 A PREVIOUSLY UNREPORTED DE NOVO FRAGILE SITE [fra(2)(q37)] IN A BOY WITH DEVELOPMENTAL DELAY, HYPOTONIA AND DYSMORPHISM

Abstract

The patient was born at term with a birth weight of 2.84 Kg. At age 12 months he was not sitting up or responding. At 15 months he could not stand, with hypotonia of legs and a ? history of myoclonic seizures. At 21 months he presented as a thin boy with hypertelorism, epicanthal folds, pectus excavatum, hammer-toe deformities of the great toes and a head that appeared small. Analysis of GTG-banded, cultured peripheral lymphocytes revealed a karyotype of 46,XY,fra(2)(q37). The fragility on chromosome 2 was present in 100% of the cells examined. The appearance of the fragile site varied from that of a secondary constriction to an isochromatid break. It was seen in lymphocytes cultured in Ham's F-10 synthetic medium, plus 20% calf serum. No inducing agents like FUdR, BUdR, anti-folates or distamycin were present. The parents had normal karyotypes. It is of interest that the father was exposed to Agent Orange spray in Vietnam in 1968 and 1969. There are two areas of possible causality which are unresolved in this case: the relation of the dysmorphism and developmental delay to the fragile site, and in turn its relationship (if any) to Agent Orange.