Levy-Shanske syndrome: mosaic tetrasomy 15q25.3→qter and review of the literature

Introduction: Tetrasomy for the distal chromosome 15q is rare. Only 24 cases have been described in the literature to date. Tetrasomy for the distal portion of chromosome 15q can be due to a supernumerary analphoid marker chromosome consisting of an inverted duplication of the distal long arm of chromosome 15. We report on a molecular cytogenetic diagnosis of mosaic tetrasomy 15q25.3-qter in a patient with multiple congenital anomalies. Aim: Molecular cytogenetic diagnosis of mosaic case with inverted duplication for the distal portion of 15q25.3→qter in a patient with multiple congenital anomalies and review of the literature. Methods: The case of mosaic supernumerary marker chromosome was characterized by GTG-banding, chromosomal microarray analysis and FISH diagnosis. Results: The chromosome analysis of a child revealed a supernumerary marker chromosome in mosaicism: 47,ХХ,+mar[8]/46,XX[23]. Chromosomal microarray analysis detected a copy gain of 16.4 Mb from the distal long arm of chromosome 15. Further FISH analysis showed an inverted duplication of distal long arm of chromosome 15 with neocentromere. Conclusion: Identification of structure and origin supernumerical marker chromosomes at patients with multiple congenital anomalies is an important problem of cytogenetic diagnostics. Modern molecular -cytogenetic diagnostic methods of chromosomal anomalies allow identifying and characterizing any case of neocentromeres.

малая сверхчисленная маркерная хромосома, тетрасомия 15q, неоцентромера, мозаицизм, FISH, хромосомный микроматричный анализ, Small supernumerary marker chromosome, tetrasomy 15q, neocentromere, mosaicism, FISH, array-CGH