Duplication of part of 9q due to maternal 12;9 inverted insertion associated with pyloric stenosis

Abstract
We report on a 9‐month‐old boy who had duplication of the long arm of chromosome 9 [46,XY,−12,+der(12) inv ins (12;9)(p13;q32q13)mat.]. The clinical manifestations of the patient were different from those seen in distal 9q duplication. Pyloric stenosis appears to be common in cases with proximal 9q duplications.