Ring chromosome 9 with a 9p22.3-p24.3 duplication

A ring chromosome 9 containing an inverted 9p22.3-p24.3 duplication was found in a girl presenting with some of the phenotypic characteristics of ring 9 syndrome such as trigonocephaly, microcephaly, hypotelorism, micrognathia, single palmar crease, and bilateral clinodactyly. The typical facial dysmorphic features of 9p duplication, ascribed to trisomy of the band p22, were not present in this patient. Cytogenetic and molecular studies indicated that the duplicated region of band p22 in the ring is confined to the sub-band 22.3. Conclusion: The chromosome region responsible for the 9p duplication syndrome appears to be restricted to sub-bands p22.1-22.2.