Two new mutations in the CEL gene causing diabetes and hereditary pancreatitis: How to correctly identify MODY8 cases

Objective Maturity-onset diabetes of the young, type 8 (MODY8) is associated with mutations in the CEL gene, which encodes the digestive enzyme carboxyl ester lipase. Several diabetes cases and families have in recent years been attributed to mutations in CEL without any functional or clinical evidence provided. To facilitate correct MODY8 diagnostics, we screened two cohorts of diabetes patients and delineated the phenotype. Research design Young, lean Swedish and Finnish patients with a diagnosis of type 2 diabetes (352 cases, 406 controls) were screened for mutations in the CEL gene. We also screened 58 Czech MODY cases who had tested negative for common MODY genes. For CEL mutation-positive subjects, family history was recorded, and clinical investigations and pancreatic imaging performed. Results One Swedish and one Czech case with germline mutation in CEL were identified. Clinical and radiological investigations of these two probands and their families revealed dominantly inherited insulin-dependent diabetes, pancreatic exocrine dysfunction and atrophic pancreas with lipomatosis and cysts. Notably, hereditary pancreatitis was the predominant phenotype in one pedigree. Both families carried single-base pair deletions in the proximal part of the CEL variable number of tandem repeat (VNTR) region in exon 11. The mutations are predicted to lead to aberrant protein tails that make the CEL protein susceptible to aggregation. Conclusions The diagnosis of MODY8 requires a pancreatic exocrine phenotype and a deletion in the CEL VNTR in addition to dominantly inherited diabetes. CEL screening may be warranted also in families with hereditary pancreatitis of unknown genetic etiology.

Long-Term Outcome and Treatment in Persistent and Transient Congenital Hyperinsulinism: A Finnish Population-Based Study

Context The management of congenital hyperinsulinism (CHI) has improved. Objective To examine the treatment and long-term outcome of Finnish patients with persistent and transient CHI (P-CHI and T-CHI). Design A population-based retrospective study of CHI patients treated from 1972 to 2015. Patients 106 patients with P-CHI and 132 patients with T-CHI (in total, 42 diagnosed before and 196 after year 2000) with median follow-up durations of 12.5 and 6.2 years, respectively. Main Outcome Measures Recovery, diabetes, pancreatic exocrine dysfunction, neurodevelopment. Results The overall incidence of CHI (n = 238) was 1:11 300 live births (1972-2015). From 2000 to 2015, the incidence of P-CHI (n = 69) was 1:13 500 and of T-CHI (n = 127) 1:7400 live births. In the 21st century P-CHI group, hyperinsulinemic medication was initiated and normoglycemia achieved faster relative to earlier. Of the 74 medically treated P-CHI patients, 68% had discontinued medication. Thirteen (12%) P-CHI patients had partial pancreatic resection and 19 (18%) underwent near-total pancreatectomy. Of these, 0% and 84% developed diabetes and 23% and 58% had clinical pancreatic exocrine dysfunction, respectively. Mild neurological difficulties (21% vs 16%, respectively) and intellectual disability (9% vs 5%, respectively) were as common in the P-CHI and T-CHI groups. However, the 21st century P-CHI patients had significantly more frequent normal neurodevelopment and significantly more infrequent diabetes and pancreatic exocrine dysfunction compared with those diagnosed earlier. Conclusions Our results demonstrated improved treatment and long-term outcome in the 21st century P-CHI patients relative to earlier.

An Unusual Case of Fulminant Type 1 Diabetes during the Second Trimester of Pregnancy

Fulminant type 1 diabetes is a new subtype of rapid-onset type 1 diabetes, with pancreatic exocrine dysfunction, that usually develops during the third trimester of pregnancy. We describe a patient with fulminant type 1 diabetes onset during her second trimester, resulting in premature delivery. The 34-year-old woman, without any known risk factors for diabetes mellitus, experienced a sudden stillbirth at 24-weeks gestation. Her blood glucose level was 950 mg/dL and she was positive for urine ketone bodies. The condition met all the diagnostic criteria for fulminant type 1 diabetes, and was diagnosed as such. Although this disease is rare, its progression is rapid, and its clinical course is severe and occasionally leads to death; therefore, a full knowledge of the disease is important to facilitate an accurate diagnosis.