357 O. ALDEMIR ET AL, RING CHROMOSOME 9 IN A NEWBORN GENETIC COUNSELING, Vol. 24, No 4, 2013, pp 357 - 360 RING CHROMOSOME 9 IN A NEWBORN BY O. ALDEMIR ¹, I.H. CELIK ², K. KARAER ³ AND G. CEYLANER ³ (1) Mersin Maternity and Children Hospital Medical Genetic, Mersin, Turkey. (2) Mersin Maternity and Children Hospital Neonatology, Mersin, Turkey. (3) Intergen Genetic Research and Diagnostic Center, Ankara, Turkey. Summary: Ring chromosome 9 in a newborn: Ring chromosome 9 is a rare genetic disorder observed in the children with variable clinical presentation and phenotype. Among several ring formation, individuals with r(9) generally have less distinct clinical features. We examined in a newborn patient with trigonocephaly, upward-slanting palpebral fissures, small face, micrognathia, high arched palate, low set ears, hypertrichosis and broad eyebrows, short neck and we diagnosed this patient as ring chromosome 9 by chromosomal analysis. We compared the clinical findings of our cases with previously reported patients in the literature. Key-words: Ring chromosome 9 – Trigonocephaly – Hypertrichosis. INTRODUCTION Ring chromosome 9 is well-defined chromosomal abnormality and there were reported few patients (nearly over then 25) in the literature. Individuals presenting with ring chromosome 9 are extremely rare. Due to the limited number of reported cases, a definitive syndrome has yet to be defined. Some researchers have reported that patients with ring chromosome 9 manifest features similar to those exhibited in partial del(9p)(1, 3, 4). The mechanism of cytogenetic defect of ring chromosome is usually the results of a de novo defect. Craniofacial findings are trigonocephaly, upward-slanting palpebral fissures, growth retardation, mental retardation, microcephaly, ab- normal testes, strabismus, high arched palate, cardiac defects, widely spaced nipples, hypertelorism, short neck, long slender fingers, seizu- res, abnormalities of external genitalia (2, 3, 5, 6, 8). CLINICAL REPORT The newborn patient was referred from Pediatric Neonatology clinic because of his dysmorphic appearence. They are following up with respiratuar problems. Prenatal history was normal. He was born via C/S and his birth weight was 3200 g. We evaluated our patient’s an- thropometric measurements; height:52cm (-2 SD), weight: 3.700gr (- Art 1.indd 357 23/10/2013 9:36:46