Kidney Week

Abstract: TH-PO533

An Infantile Nephrotic Syndrome Case Caused by COQ6 Gene Defects Revealed by Pair Analysis and Custom Array CGH

Session Information

• Trainee Case Reports - I
  October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Trainee Case Reports

• 1600 Pediatric Nephrology

Authors

• Nakanishi, Keita, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Keita Nakanishi,

• Nozu, Kandai, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Kandai Nozu,

• Okamoto, Takayuki, Hokkaido University Graduate School of Medicine, Sapporo, Japan

Takayuki Okamoto,

• Hayashi, Asako, Hokkaido University Graduate School of Medicine, Sapporo, Japan

Asako Hayashi,

• Takahashi, Toshiyuki, Hokkaido University Graduate School of Medicine, Sapporo, Japan

Toshiyuki Takahashi,

• Sakakibara, Nana, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Nana Sakakibara,

• Nagano, China, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

China Nagano,

• Fujimura, Junya, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Junya Fujimura,

• Horinouchi, Tomoko, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Tomoko Horinouchi,

• Minamikawa, Shogo, Kobe University Graduate School of Medicine, Kobe, Japan

Shogo Minamikawa,

• Yamamura, Tomohiko, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Tomohiko Yamamura,

• Kaito, Hiroshi, Hyogo Prefectural Kobe Children's Hospital, Kobe, Japan

Hiroshi Kaito,

• Shima, Yuko, Wakayama Medical University, Wakayama City, Japan

Yuko Shima,

• Nakanishi, Koichi, Graduate School of Medicine, University of the Ryukyus, Nishihara-cho, Japan

Koichi Nakanishi,

• Iijima, Kazumoto, Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan, Kobe, Japan

Kazumoto Iijima,

Introduction

Comprehensive genetic analysis using next-generation sequencer (NGS) of causative genes for steroid resistant nephrotic syndrome (SRNS) have been established all over the world currently.
It enables us to treat some kinds of monogenic SRNS patients with specific therapies and improve the renal prognosis; Coenzyme Q10 (CoQ10) supplementation for patients with CoQ10 deficiency related gene variants, such as COQ6, PDSS2, COQ2, and ADCK4. In this study, we conducted NGS analysis for the infantile SRNS patient, and to detect a copy number variation (CNV), we performed NGS data-based pair analysis and custom array CGH.

Case Description

Patient was a 1-year-old boy. He was diagnosed with SRNS and performed a renal biopsy. Electron microscopic examination revealed abnormal mitochondria (dysmorphic mitochondria, lacking cristae or abnormal proliferation) in podocytes. We conducted targeted panel sequencing analysis using NGS and detected only one COQ6 monoallelic reported variant on maternal allele (c.782C>T, p.Pro261Leu). Next, we conducted CNV analysis with pair analysis using the NGS analysis data and custom array CGH. Both analysis successfully detected the same copy number changes in exons 1–2 of the COQ6 gene on paternal allele. He was thus started supplementation of CoQ10, and remission was achieved.

Discussion

Comprehensive gene screening system with NGS were effective method to detect causative gene variants in SRNS. In addition, conducting pair analysis and custom array CGH were remarkably useful to detect CNVs. Specific therapy of CoQ10 for the patient carrying COQ6 mutations was very effective when it was started in the early stages, so try not to miss the opportunity for the cases with CoQ10 glomerulopathies starting supplementation.