Tohoku J. Exp. Med., 2022 January, 256(1)

Identification of a Novel Mutation in Carboxyl Ester Lipase Gene in a Patient with MODY-like Diabetes

Tomomi Kondoh,1 Yoko Nakajima,1 Katsuyuki Yokoi,1 Yuji Matsumoto,1 Hidehito Inagaki,2 Takema Kato,2 Yoichi Nakajima,1 Tetsuya Ito,1 Tetsushi Yoshikawa1 and Hiroki Kurahashi2

1Department of Pediatrics, Fujita Health University School of Medicine, Toyoake, Aichi, Japan
2Division of Molecular Genetics, Institute for Comprehensive Medical Science, Fujita Health University School of Medicine, Toyoake, Aichi, Japan

Maturity-onset diabetes of the young (MODY) is a form of diabetes mellitus characterized by autosomal dominant inheritance, early onset, and the absence of pancreatic autoimmune markers. MODY-causing mutations have been identified in 14 genes, and carboxyl ester lipase (CEL) has been implicated in MODY8. We report a Japanese patient with MODY who harbored a heterogeneous mutation in CEL exon 2 (NM_001807.4:c.146_147delCT; NP_001798.2:p.Ser49CysfsTer52). A 13-year-old girl experienced her first episode of diabetic ketoacidosis, during which her endogenous insulin secretion was poor. However, her insulin secretion had apparently recovered 2 months after the commencement of insulin treatment, and no further treatment was required for the following 2 years. Diabetic ketoacidosis recurred when the patient was 15 years old, when her insulin secretion was again poor. Since that time, the patient, who is now 18 years old, has been undergoing continuous insulin treatment. The large fluctuations in her insulin secretory capacity led us to suspect MODY. MODY8 patients that carry a mutation in the variable number of tandem repeats in the last exon of the CEL gene typically show pancreatic exocrine dysfunction. However, in the present case, which features premature termination, there is no involvement of exocrine dysfunction, potentially demonstrating a genotype-phenotype correlation.

Keywords —— carboxyl ester lipase; diabetes mellitus; maturity-onset diabetes of the young; MODY8; pancreatic exocrine dysfunction

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Tohoku J. Exp. Med 2022, 256, 37-41.

Correspondence: Yoko Nakajima, Department of Pediatrics, Fujita Health University, 1-98 Dengakugakubo, Kutsukake-cho, Toyoake, Aichi 470-1192, Japan.

e-mail: yonaka@fujita-hu.ac.jp