# Novel variation in the CEL gene causing impaired fasting glucose in a Chinese pediatric patient: case report and literature review

## TL;DR

A 12-year-old boy with a new CEL gene mutation showed early diabetes without pancreatic issues, highlighting the varied effects of this rare genetic condition.

## Contribution

A novel CEL gene mutation (c.1809dupC) was identified in a pediatric patient with mild diabetes and no exocrine dysfunction.

## Key findings

- A novel CEL gene mutation was found in a child with impaired fasting glucose but no pancreatic exocrine dysfunction.
- CEL-MODY in children shows phenotypic heterogeneity, possibly linked to mutation type and age of onset.
- Lifelong monitoring of pancreatic function is recommended for patients with CEL gene mutations.

## Abstract

CEL-related Maturity-Onset Diabetes of the Young (CEL-MODY) is a rare form caused by carboxyl ester lipase (CEL) gene mutations. It is characterized by dysglycemia and pancreatic exocrine dysfunction. We described a case to highlights the heterogeneity of clinical manifestations of the CEL gene mutations in pediatric patients.

We report a 12-year-old boy presenting with impaired fasting glucose. The patient reported no abdominal pain. Magnetic resonance imaging (MRI) of the pancreas revealed no evidence of pancreatic atrophy, fatty infiltration, or other abnormalities. Additionally, the fecal elastase level was within the normal range. Genetic analysis identified a novel heterozygous mutation in the CEL gene (c.1809dupC). The child exhibited only early-stage diabetes without concomitant pancreatic exocrine insufficiency, indicating a phenotypically mild form.

Children with CEL gene mutations appear to exhibit significant phenotypic heterogeneity. It may be correlated with both the specific mutation type and age at disease onset. Thus, lifelong, systematic monitoring of pancreatic endocrine and exocrine function is clinically necessary.