MG-121 Five new patients with pure distal 1q trisomy, review of the literature and phenotype redefinition. (4th December 2015) - Maftei, Catalina
Abstract : Background: Pure distal 1q trisomy is rare and there is limited information on genotype-phenotype correlation. The common 1q trisomy phenotype attributed to the 1q42qter segment is based on a small number of patients and consists of small for gestational age, developmental delay, macrocephaly, dysmorphic features and heart defects. Objective: To clarify the genotype-phenotype correlation of pure distal 1q trisomy. Design/method: We report five patients with pure distal 1q trisomy: 1q32.2qter (patient 1), 1q41q44 (patient 2), 1q43qter (patient 5) and 1q42.13qter in two siblings (patient 3 and 4). A PubMed search was done to identify patients with trisomies distal to 1q32. Patients with pure 1q trisomies that matched the duplications found in our patients were selected. Results: Thirty-three patients have been reported with partial trisomy distal to 1q32. Only 17 patients with pure 1q trisomy matched our patients': ten for 1q32qter, four for 1q41q44, two for 1q42qter and one for 1q43qter. Our patients presented additional features than the common 1q trisomy phenotype. Patients 1, 2, 3 and 4 have had frequent infections with normal immunological status. Patients 1, 3 and 4 had significant sleeping problems. Patients 3 and 4 have camptodactyly and patient 4 had hypertrophied cardiomyopathy. Patients 4 and 3 respectively have moderate and mild intellectual deficiency, a feature that was thought to be mostly normal distal to the 1q42 region. Conclusions: The partial 1q trisomy phenotype is constantly expanding. An improved definition allows for the identification of critical regions and better genetic counselling and follow up.