Ring chromosome 9 in a girl with developmental delay and dysmorphic features: case report and review of the literature.

In this report, we describe a female child with dysmorphic features and developmental delay. Chromosome microarray analysis followed by conventional karyotyping revealed a ring chromosome 9 with a 12 Mb deletion at 9pter-p23 and a 540 kb deletion at 9q34.3-qter. Four percent of the analyzed cells had monosomy 9. The patient has the features of both the Kleefstra syndrome and the chromosome 9p-syndrome, including trigonocephaly, long philtrum, hypertelorism, and retro-/micronagthia. The deletion of the patient overlaps with several of the proposed critical regions for the 9p deletion syndrome.