Duplication Syndrome and Its Association with Kidney Disease

Introduction: Williams-Beuren Syndrome (WS) refers to a segment on chromosome 7 that, when absent, is associated with WS. Conversely, duplicating this segment can lead to Duplication 7 Syndrome (Dup 7). Duplication syndrome is a rare genetic disorder characterized by developmental delay, impairment of the kidneys, and behavioral abnormalities. Here, we describe a case of 7q11.23 duplication exhibiting such features. Duplication syndrome follows an autosomal dominant inheritance pattern and is characterized by an extra copy of a region on the long (q) arm of chromosome 7. Due to its rarity, duplication syndrome may be misinterpreted as a psychological disorder due to the limited information available about the condition and also remains a critical etiology for kidney disease. In the current case, the 7q11.23 duplication was identified many years after the initial presentation. Case Description: A 19-year-old male with a solitary kidney presented to our nephrology clinic for persistent chronic kidney disease of unknown etiology. His medical history included autism absence seizures, chronic kidney disease stage 3a, and developmental disorder. During infancy, he faced unexplained growth issues and episodes of pneumonia, prompting negative tests for cystic fibrosis. His family history revealed a father with epilepsy. On examination, he was afebrile with no notable physical abnormalities except for agitation. Initial laboratory tests returned unremarkable results with a creatinine of 1.45 mg/dl. Neurological evaluations showed no abnormalities to explain his persistent behavioral symptoms. A psychiatric assessment highlighted speech and behavariol issues. Despite multiple medication trials yielding no improvement, consultation with a geneticist was pursued, considering a potential genetic association due to his solitary kidney. A breakthrough occurred when the geneticist identified a 7q11.23 duplication, shedding light on the underlying cause of his complex medical presentation. Discussion: Diagnosing rare genetic conditions like 7q11.23 duplication syndrome requires teamwork and thorough exploration of family medical history. Early identification and intervention are vital for managing kidney disease and seizures, offering clarity and psychological relief. While treatment options may be limited, understanding the illness's cause brings psychological benefits and encourages further learning.