Case Report: Opitz C Syndrome with a Rare Chromosomal Abnormality

Abstract

Opitz Trigonocephaly C syndrome (OTCS) or Opitz C Syndrome or C syndrome is a congenital malformation syndrome characterized by trigonocephaly, mental retardation and several other dysmorphic features. Commonly reported chromosomal abnormalities associated with trigonocephaly include 3q-, 7p-, 9p-, 11q-, and trisomy 13q. The present case report describes a patient with derivative 7, due to an unbalanced translocation t(7;13)(p22;q21), with a clinical phenotype of OTCS. To the best of researchers’ knowledge, this is the second published case report on Opitz Trigonocephaly C syndrome with similar chromosomal abnormality from India. Address for correspondence: Dr. Jaya Vyas Consultant-Genetics and Molecular Medicine Kokilaben Dhirubhai Ambani Hospital and Medical Research Center Andheri (W), Maharashtra, Mumbai 400 053, Maharashtra, India Telephone:+91-22-30696969 Mobile: 902 2942 570 Fax: 91-22-30970177 E-mail: jaya.vyas@relianceada.com INTRODUCTION Individuals with trigonocephaly, (a striking feature in Opitz Trigonocephaly C syndrome) have a keel-shaped forehead with wide biparietal diameter, resulting in a triangular shape of the head. It results from premature closure of the metopic sutures and usually occurs sporadically. Trigonocephaly can be syndromic or non-syndromic. Opitz Trigonocephaly C syndrome (OTCS) (OMIM C SYNDROME #211750) McKusick (1998), is a congenital malformation syndrome characterized by trigonocephaly, mental retardation, hypotonia, variable cardiac defects, redundant skin, and dysmorphic facial features, including upslanted palpebral fissures, epicanthal folds, depressed nasal bridge, and low-set, posteriorly rotated ears (Chinen et al. 2006). Opitz et al. (1969) had first described a brother and sister with a multiple malformation syndrome including trigonocephaly. Since then, around 60 cases of OTCS with similar phenotypes have been described. Commonly reported chromosomal abnormalities in trigonocephaly include 3q-, 7p-, 9p-, 11q-, trisomy 13q and duplication of chromosome 20q11.2. (de Grouchy et al. 1984; Borgaonkar et al. 1997; Avila et al. 2013). In this case report, researchers present a case of OTCS with an unbalanced translocation between chromosome 7 and 13, resulting in partial trisomy of chromosome 13q and no apparent loss of genetic material in chromosome 7.