ß 2008 Wiley-Liss, Inc. American Journal of Medical Genetics Part A 146A:2955–2959 (2008) Research Letter Molecular Cytogenetic Characterization of a de novo Mosaic Supernumerary Ring Chromosome 7: Report of a New Patient Veronica Bertini, 1 * Angelo Valetto, 1 Angela Uccelli, 1 Alice Bonuccelli, 2 Enrico Tarantino, 3 Grazia Taddeucci, 2 and Paolo Simi 1 1 Cytogenetics And Molecular Genetic Unit, A.O.U. Pisana, Ospedale S. Chiara, Pisa, Italy 2 Neurological Section, Pediatric Department, A.O.U. Pisana, Ospedale S. Chiara, Pisa, Italy 3 Medical Genetics Section, Pediatric Department, A.O.U. Pisana, Ospedale S. Chiara, Pisa, Italy Received 28 December 2007; Accepted 27 June 2008 How to cite this article: Bertini V, Valetto A, Uccelli A, Bonuccelli A, Tarantino E, Taddeucci G, Simi P. 2008. Molecular cytogenetic characterization of a de novo mosaic supernumerary ring chromosome 7: Report of a new patient. Am J Med Genet Part A 146A:2955 – 2959. To the Editor: Here, we report on a patient with a de novo, mosaic, supernumerary r(7) chromosome. The patient (Fig. 1a,b), a 10-year-old girl, was born at 41 weeks of gestation after an uneventful pregnancy. She was the first child of healthy and unrelated parents, age 30 (mother) and 31 (father); her younger brother (5-year-old) was healthy. Family history was negative for congenital anomalies and/or psychomotor retardation excluding a father’s cousin with language developmental delay; unfortunately, he was not available for karyotype or clinical investigation. The birth weight was 4,030 g (>97th centile), length 51 cm (75th centile) and OCF 36 cm (50th centile). No clinical symptoms were reported in the neonatal period. Her motor development was slightly delayed: she was hypotonic at birth and was sitting at age of 9 months; walking abilities were in the normal range and since the age of 12 months, she could walk without support. However, speech was severely delayed: first words were not until 3 years of age, and her language skills were delayed with poor performances on the expressive side. No hearing loss was detected. She was referred by the local pediatrician at age of 5 years because of language delay. At this time her weight was 24.8 kg (95th centile), height 114 cm (90th centile), and OCF 53 cm (97th centile). Physical examination showed a flat face, high and prominent forehead, deep-set eyes, short nose, prominent nasal root close to frontal bone, short philtrum, thick columella, thin lips, relative microstomia with down- turned corners, and low set ears. Palmar creases and digits were normal but her fingers had wide nails; a partial cutaneous syndactyly was present between 2nd and 3rd toe. No signs of premature puberty were present, but she showed hirsutism on the dorsal side of her limbs and a cafe ´-au-lait macula on the abdomen. Ophthalmology evaluation showed a mild astigmatism. A soft cardiac murmur was present, but cardiac evaluation, EKG, and heart echocardio- graphy were normal. Abdominal ultrasound revealed no visceral anomalies. A cerebral MRI showed dilatation of the ventricles and cisterna magna, whereas the results of an awake EEG were in the normal range. Hematologic and neuro-metabolic screenings were normal. Her slightly retarded psychomotor development improved with time. Recently, she demonstrated no learning difficulties at school and her cognitive development fell into normal lower limits (WISCR scale). Her performances were lowered by verbal difficulties (mostly in the phonologic, semantic and syntactic areas). Karyotype analysis of 100 metaphases showed the presence of a supernumerary marker chromosome (SMC) in about 50% of cells. The marker was shaped like a ring, C-band positive, DA-DAPI and AgNOR negative. Parental karyotypes were normal. Veronica Bertini and Angelo Valetto contributed equally to this work. *Correspondence to: Veronica Bertini, Ph.D., Molecular Genetic Unit, A.O.U. Pisana, Ospedale S. Chiara, via Roma 57, 56100 Pisa, Italy. E-mail: v.bertini@ao-pisa.toscana.it Published online 16 October 2008 in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/ajmg.a.32528