Phenotype of a Patient With Pure Partial Trisomy 2p(p23→pter) Muna Al-Saffar, 1,2 Emmanuelle Lemyre, 2,3 Robert Koenekoop, 2,4 Alessandra M. V. Duncan, 2,3 and Vazken M. Der Kaloustian 1,2 * 1 F. Clarke Fraser Clinical Genetics Unit, Division of Medical Genetics, Montreal Children’s Hospital, Montreal, Quebec, Canada 2 McGill University, Montreal, Quebec, Canada 3 Department of Pathology, Montreal Children’s Hospital, Montreal, Quebec, Canada 4 Department of Ophthalmology, Montreal Children’s Hospital, Montreal, Quebec, Canada We present the case of a 7-month-old girl with the karyotype 46,XX, der(13) t(2;13)(p23;p11.2).ish der(13)(wcp2+) de novo. Painting confirmed that the addi- tional segment on 13p was of chromosome 2 origin, resulting in trisomy 2p23 →2pter. The child had a prominent forehead with a flat hemangioma, depressed nasal bridge, protruding tongue, posteriorly angulated ears, esotropia with poor abduction of the right eye, bilateral severe myopia (-5.5 D), retinal hypopigmentation, foveal hypopla- sia, and striking left optic nerve hypoplasia. She also had pectus excavatum, a protrud- ing abdomen with diastasis recti, general- ized hypotonia, delayed fine and gross mo- tor development, grade II reflux on the left side, and grade III–IV reflux on the right side. An EEG showed epileptiform dis- charges. Computed tomographic scan of the brain showed decreased white matter, but magnetic resonance imaging showed nor- mal results. Am. J. Med. Genet. 94:428–432, 2000. © 2000 Wiley-Liss, Inc. KEY WORDS: de novo pure partial trisomy 2p; 2p23→2pter; eye abnor- malities INTRODUCTION Usually, partial trisomy 2p is associated with partial monosomy of another chromosomal segment, since most reported cases have resulted from a balanced translocation in one of the parents [Lurie et al., 1995]. However, there are some reports of duplications that occur de novo [Yunis et al., 1979; Say et al., 1980; Mon- teleone et al., 1981; Wakita et al., 1985; Fryns et al., 1989; Parruti et al., 1989; Heathcote et al., 1991; Ma- gee et al., 1994; Siffroi et al., 1994; Me ´garbane ´ et al., 1997]. The size of the duplicated 2p segment ranges from a single band, p25.1→p25.3 [Wakita et al., 1985], to a larger segment, p13→pter, involving most of the distal short arm of chromosome 2 [Monteleone et al., 1981]. So far partial trisomy of 2p23→2pter has been con- firmed in 12 liveborn cases. In all of these cases, un- balanced translocations were inherited, associated with deletion of various chromosomes [Bender et al., 1969; Carriere, 1975; Magenis et al., 1975; Francke and Jones, 1976; Cassidy et al., 1977; Neu et al., 1979; Rosenfeld et al., 1982; Fineman et al., 1983; Lurie et al., 1995]. As a result of the associated partial mono- somies of diverse chromosomes, these patients have different phenotypes. There is no report of de novo di- rect duplication of 2p23→2pter. Our patient represents the only case known to us of pure trisomy of this seg- ment. CLINICAL REPORT BA was born to a 29-year-old mother (gravida 3 para 2). The non-consanguineous parents are of French- Canadian descent and are healthy. The family history is unremarkable. The pregnancy was complicated by first-trimester bleeding and premature contractions. There was no history of exposure to ethanol, cigarettes, or other teratogens. The delivery was spontaneous at term. Apgar scores were 6, 9, and 9 at 1, 5, and 10 min, respectively. The birth weight was 3,000 g (25th per- centile), the length was 51 cm (75th percentile), and the occipitofrontal circumference (OFC) was 34 cm (50th percentile). Hypotonia was noted at birth. The infant was transferred to Montreal Children’s Hospital be- cause of the possibility of a congenital heart defect. Moderate-sized muscular ventricular septal defect and atrial septal defect were detected. We evaluated BA at 4 months of age. On examina- tion, she weighed 4,390 g (5th percentile) and had a Grant sponsor: Fonds de la Recherche en Sante ´ du Que ´bec. *Correspondence to: Vazken M. Der Kaloustian, M.D., F. Clarke Fraser Clinical Genetics Unit, Division of Medical Genet- ics, Montreal Children’s Hospital, 2300 Tupper Street, Montreal, Quebec, H3H 1P3, Canada. E-mail: mddk@musica.mcgill.ca Received 1 March 2000; Accepted 1 June 2000 American Journal of Medical Genetics 94:428–432 (2000) © 2000 Wiley-Liss, Inc.