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.