Distal 3p Duplication and 22q13.3 Deletion with Severe Hypotonia Originating from a Paternal Balanced Translocation (3;22)

Abstract

In this study, we present a case with distal 3p duplication and 22q13.3 deletion due to unbalanced meiotic segregation in her father carrying a balanced translocation. The 2-month-old girl was examined for her severe hypotonia, developmental delay, and mild dysmorphic appearance. Clinical features include broad forehead, hypertelorism, laterally extended eyebrows, long eyelashes, a depressed nasal root, bifid nasal tip, long philtrum, thin lips, posteriorly rotated ears, short neck, partial syndactyly of the right hand (fingers 3, 4), and partial syndactyly of the right foot (toes 2, 3). After examination, the final karyotype was reported as: 46,XX,der(22)del(22)(qter)dup(3)(p22pter), and the array-CGH results showed arr[GRCh37] 3p26.3p22.1(93949_41518607)×3 and arr[GRCh37] 22q13.31q13.33(44554083_51224252)×1. The mother has a 46,XX karyotype, and her father carries a balanced translocation, 46,XY,t(3;22)(p26.3;q13.3). This is the first case with a distal 3p duplication and 22q13.3 deletion with severe hypotonia and developmental delay.