Donohue syndrome: A review of literature, case series, and anesthetic considerations.

BACKGROUND: Donohue syndrome is a rare autosomal recessive disorder of insulin resistance, causing a functional defect in insulin receptor function, and affecting the ability of the insulin to bind the receptor. Features include severe hyperinsulinism and fasting hypoglycemia, along with severe failure to thrive despite feeding. An accelerated fasting state results in muscle wasting, decreased subcutaneous fat, and an excess of thick skin. A reduced thoracic diameter is accentuated by increased abdominal distension, which impacts on respiratory reserve. Cardiac disease develops early in life, with progressive hypertrophic cardiomyopathy as a result of hyperinsulinism. Prognosis is poor with the majority of patients dying in infancy of sepsis. The aim of this review is to report our experience of providing anesthesia for patients with Donohue syndrome, and inform guidance for safe management of these children, based on a comprehensive literature review. METHODS: A literature search was carried out using PubMed, Medline, and the Cochrane Library, and using the MESH search terms detailed below. Patients were identified by formal request to the department of pediatric endocrinology at Great Ormond Street Hospital. Each patient's notes were searched manually and electronically for both clinical presentation and outcome, and anesthesia records. DISCUSSION: There is currently no published literature relating to anesthetic management of Donohue syndrome. We report a case series of 5 patients with Donohue syndrome who have presented to our institution. This small series of children with this complex disorder demonstrates a clearly increased risk of general anesthesia. Many of the risks relate to restrictive lung disease and abdominal distension which worsens with bag valve mask ventilation and limited respiratory reserve which leads to precipitous desaturation. During induction, a spontaneously breathing technique is recommended. If required, bag valve mask ventilation should be accompanied by constant gastric aspiration. Intubation is challenging, and a difficult airway plan, including a second experienced anesthetist and ENT support, should be in place. These children are predisposed to developing cardiomyopathy and therefore at risk of cardiovascular collapse under anesthesia.

Gastrointestinal dysmotility and pancreatic insufficiency in 2 siblings with Donohue syndrome.

Donohue syndrome is a rare congenital syndrome of insulin-resistance and abnormal glucose homeostasis, caused by mutations in the insulin receptor (INSR) gene. It is characterized by specific phenotypic and clinical features and the diagnosis is based on clinical, biochemical and genetic criteria. We report 2 siblings with Donohue syndrome (cases 1, 2) with multiple clinical and biochemical characteristics. Both patients shared the same mutation and presented with intra-uterine growth restriction, failure to thrive, fasting hyperinsulinaemic hypoglycaemia and episodic post-prandial hyperglycaemia. Less common clinical features were also present, such as atrial septal defect and biventricular hypertrophy, clotting disorders, abnormal liver function tests and nephrocalcinosis. Interestingly, 2 previously unrecognized manifestations of the syndrome were also identified: severe gastrointestinal dysmotility (case 1) and exocrine pancreatic insufficiency (case 2). The co-existence of all the above clinical features makes these cases extremely rare. Gastrointestinal dysmotility should always be considered as a potentially fatal feature in patients with the syndrome, due to the complexity of the possible co-morbidities. In addition, our clinical experience for the first time suggests that pancreatic exocrine insufficiency may offer a possible explanation for the growth retardation observed in some patients with this syndrome. Our finding that replacement treatment with pancreatic enzymes improved weight gain (case 2) implies that all patients with Donohue syndrome should be investigated for exocrine pancreatic insufficiency.

Ten-year improvement of insulin resistance and growth with recombinant human insulin-like growth factor 1 in a patient with insulin receptor mutations resulting in leprechaunism.

AIM: Leprechaunism, a rare genetic disease resulting from mutations in two alleles of the insulin receptor gene, is characterized by severe insulin resistance, retarded growth and, usually, premature death. The ability of treatment with recombinant human insulin-like growth factor 1 (rhIGF1) to improve metabolic and clinical parameters in the long-term is still controversial. METHODS: Mutations were looked for in the insulin receptor gene of a four-month-old female baby with leprechaunism. The patient's skin fibroblasts were analyzed for response to insulin and IGF1. At the clinical level, the very long-term effects of treatment with rhIGF1/rhIGFBP3 were evaluated by clinical and metabolic parameters. RESULTS: The patient's diagnosis was based on compound heterozygous mutations in two alleles of the insulin receptor gene, thus confirming leprechaunism. Cultured fibroblasts showed a decreased number of insulin receptors and were insulin-resistant. However, IGF1 was able to stimulate IGF1 receptor signalling, suggesting possible activation of a salvage pathway. Treatment with IGF1/IGFBP3 for 8.7 years, then IGF1 for 2 years, resulted in normalization of circulating levels of IGF1 and IGFBP3. Large daily variations in glycaemia and insulinaemia persisted, but mean glycaemia decreased. Regarding growth, the patient's BMI Z score normalized and length/height score improved. Our patient presented normal neurological development and academic achievement. The treatment was free of adverse effects. CONCLUSION: Our results provide evidence that rhIGF1 with and without rhIGFBP3 can prevent fatal outcomes, and improve growth and metabolic parameters, for more than 10 years in a patient with leprechaunism. Long-term rhIGF1 for severe insulin resistance syndrome should be considered.

Sustained regression of florid diabetic retinopathy in a patient with Donohue syndrome (leprechaunism).

PURPOSE: Leprechaunism is a rare congenital syndrome caused by mutations of the insulin receptor gene, transmitted in an autosomal recessive pattern. Insulin growth factor-1 (IGF-1) treatment can be a therapeutic option in this syndrome by its insulin-like effects. Nevertheless, it is of note that IGF-1 has also an angiogenic activity. METHODS: Fundus examination by ophthalmoscopy, fluorangiography, and laser treatment were performed. RESULTS: A 17-year-old girl with leprechaunism, under treatment with high doses of insulin, presented a florid diabetic retinopathy. The large neovascularization of the disk regressed after treatment with argon laser panretinal photocoagulation. Five years after treatment, the patient maintained good vision. CONCLUSIONS: This clinical case is of interest for 2 reasons: 1) the large retinal neovascularization was likely due to the high insulin dosages; 2) this is the first case in which a sustained regression of retinal neovascularization has been observed after laser treatment in leprechaunism.

Downregulation of Wnt-mediated ROS generation is causally implicated in leprechaunism.

Although mutations in the insulin receptor have been causally implicated with leprechaunism, the full pathophysiology of the syndrome cannot be accounted for by malfunction of this gene alone. We sought to characterize a connection between Wnt-mediated cell signaling and the production of reactive oxygen species (ROS) which revealed a novel mechanistic basis for understanding the pathogenesis of leprechaunism. To identify candidate genes involved in this process, a PCR-based subtractive hybridization was performed. Candidate genes were examined for interaction with the Wnt signaling pathway and ROS generation. We found that Dickkopf 1 (Dkk1), a Wnt inhibitor, is overexpressed in skin fibroblast cells derived from three leprechaunism patients and that the cells showed an impaired response to Wnt2 in terms of beta-catenin-Tcf activation. Knockdown of Dkk1 in the patient cell lines rescued Wnt2-mediated Tcf activation. Concerted action of Wnt2 and knockdown of Dkk1 resulted in enhanced Nox4 expression and PDGF-induced ROS generation compared to parental patient cells. Furthermore, we found that NFATc2 was activated in response to Wnt2 stimulation and directly activates Nox4 expression. These data show a crosstalk between Wnt and ROS pathways which in turn provides new mechanistic insights at the molecular level into the pathogenesis of leprechaunism.