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.