Combined pituitary hormone deficiency harboring CHD7 gene missense mutation without CHARGE syndrome: a case report.

BACKGROUND: Heterozygous loss-of-function mutations in the chromodomain helicase DNA-binding protein 7 (CHD7) gene cause CHARGE syndrome characterized by various congenital anomalies. A majority of patients with CHARGE syndrome present with congenital hypogonadotropic hypogonadism (HH), and combined pituitary hormone deficiency (CPHD) can also be present. Whereas CHD7 mutations have been identified in some patients with isolated HH without a diagnosis of CHARGE syndrome, it remains unclear whether CHD7 mutations can be identified in patients with CPHD who do not fulfill the criteria for CHARGE syndrome. CASE PRESENTATION: A 33-year-old woman was admitted to our hospital. She had primary amenorrhea and was at Tanner stage 2 for both pubic hair and breast development. She was diagnosed with CPHD (HH, growth hormone deficiency, and central hypothyroidism), and a heterozygous rare missense mutation (c.6745G > A, p.Asp2249Asn) in the CHD7 gene was identified. Our conservation analysis and numerous in silico analyses suggested that this mutation had pathogenic potential. She had mild intellectual disability, a minor feature of CHARGE syndrome, but did not fulfill the criteria for CHARGE syndrome. CONCLUSIONS: We report a rare case of CPHD harboring CHD7 mutation without CHARGE syndrome. This case provides valuable insights into phenotypes caused by CHD7 mutations. CHD7 mutations can have a continuous phenotypic spectrum depending on the severity of hypopituitarism and CHARGE features. Therefore, we would like to propose a novel concept of CHD7-associated syndrome.

Exogenous insulin antibody syndrome in a patient with diabetes secondary to total pancreatectomy.

Exogenous insulin can induce insulin antibodies that have a low affinity/high binding capacity. Similar to what is observed in insulin autoimmune syndrome, these insulin antibodies can cause fasting hypoglycemia and postprandial hyperglycemia, a phenomenon known as "exogenous insulin antibody syndrome" (EIAS). Cases of EIAS in patients with type 1 and type 2 diabetes have been sporadically reported, mainly in Asia. However, there has been no report on EIAS in patients with diabetes secondary to total pancreatectomy treated with insulin analogs. A 74-year-old man with diabetes after total pancreatectomy had been treated with continuous subcutaneous insulin infusion using an insulin analog, lispro, and developed recurrent early morning hypoglycemia even after discontinuation of nocturnal basal insulin. His fasting serum lispro level was high even approximately 9 h after the last lispro dose. He had a high titer (72.7%) of insulin antibodies, and a Scatchard analysis revealed low affinity/high binding capacity. These findings suggested that the patient's recurrent early morning hypoglycemia was associated with insulin antibodies against lispro, and we, therefore, switched from lispro to another insulin analog, glulisine. His hypoglycemia improved, accompanied by a dramatic decrease in his insulin antibodies and serum glulisine levels. Early morning hypoglycemia in patients with diabetes secondary to total pancreatectomy may often be explained by high glycemic variability, malnutrition, and/or glucagon deficiency. However, in cases of recurrent early morning hypoglycemia, EIAS should be considered as a potential differential diagnosis.

Case of slowly progressive type 1 diabetes mellitus with drastically reduced insulin secretory capacity after immune checkpoint inhibitor treatment for advanced renal cell carcinoma.

We encountered a 55-year-old Japanese man with advanced renal cell carcinoma and slowly progressive type 1 diabetes mellitus (SPT1DM), whose insulin secretory capacity was drastically reduced for a brief period after only one cycle of immune checkpoint inhibitor (ICI) treatment. The patient had been diagnosed with type 2 diabetes at the age of 53 years and was treated using oral hypoglycemic agents. However, 2 years later, he was diagnosed with SPT1DM and autoimmune thyroiditis, based on the presence of anti-glutamic acid decarboxylase antibodies (GADA) and thyroid autoantibodies, which was accompanied by advanced renal cell carcinoma. At that time, his insulin secretory capacity was preserved (CPR 2.36 ng/mL), and good glycemic control was maintained using only medical nutrition therapy (HbA1c 6.3%). He subsequently developed destructive thyroiditis approximately 2 weeks after the first cycle of ICI treatment using nivolumab (a programmed cell death-1 inhibitor) and ipilimumab (a cytotoxic T-lymphocyte-associated antigen-4 inhibitor) for advanced renal cell carcinoma. Three weeks later, his plasma glucose level markedly increased, and we detected absolute insulin deficiency and hypothyroidism. Human leukocyte antigen (HLA) analysis revealed haplotypes indicating susceptibility to type 1 diabetes mellitus (T1DM) or autoimmune thyroiditis (HLA genotype, DRB1-DQB1 *09:01-*03:03/*08:03-*06:01). He showed a good antitumor response and is currently receiving permanent insulin therapy and levothyroxine replacement with the ICI treatment. Based on this case and the available literature, patients with preexisting islet autoantibodies or SPT1DM/LADA, plus a genetic predisposition to T1DM, may have an extremely high risk of developing ICI-related T1DM for a brief period after starting ICI treatment.

Hypoglycemia during the Concomitant Use of Repaglinide and Clopidogrel in an Elderly Patient with Type 2 Diabetes and Severe Renal Insufficiency.

Hypoglycemia should be avoided when treating patients with diabetes. Repaglinide is an insulin secretagogue with a low hypoglycemic risk because of its rapid- and short-acting effects. However, its blood concentration has been reported to increase in combination with clopidogrel, an antiplatelet drug, and in patients with severe renal insufficiency. We herein report an elderly patient with type 2 diabetes mellitus and severe renal insufficiency who received repaglinide and hypoglycemia three days after starting clopidogrel. The concomitant use of repaglinide and clopidogrel can lead to hypoglycemia, especially in patients with severe renal insufficiency.