Hypertrophic cardiomyopathy with leprechaunism

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.

Two novel mutations identified in familial cases with Donohue syndrome

Donohue syndrome (DS) is a rare and lethal autosomal recessive disease caused by mutations in the insulin receptor (INSR) gene, manifesting marked insulin resistance, severe growth retardation, hypertrichosis, and characteristic dysmorphic features. We report the clinical, molecular, and biochemical characterization of three new patients with DS, and address genotype–phenotype issues playing a role in the pathophysiology of DS. A female infant born to first-degree cousins Muslim Arab parents and two brothers born to first-degree cousins Druze parents presented classical features of DS with hypertrophic cardiomyopathy and died in infancy. Each patient was found homozygous for one missense mutation within the extracellular domain of the INSR gene. Western blot analysis identified the proreceptor of INSR, but not its mature subunits alpha and beta. Of 95 healthy Muslims, no heterozygous was found and of 52 healthy Druze from the same village, one was heterozygous. This study presents two novel familial mutations in the alpha subunit of the INSR which appear to impair post-translational processing of the INSR, resulting loss of its function. Both mutations cause DS with hypertrophic cardiomyopathy and early death. Identification of the causative mutation enables prevention of this devastating disease.

Severe progressive obstructive cardiomyopathy and renal tubular dysfunction in Donohue syndrome with decreased insulin receptor autophosphorylation due to a novel INSR mutation

Donohue syndrome (leprechaunism; OMIM *246200) is a rare, recessively inherited disorder of extreme insulin resistance due to mutations in the insulin receptor gene (INSR) causing either defects in insulin binding or receptor autophosphorylation and tyrosine kinase activity. We report a patient with pronounced clinical picture of leprechaunism who developed severe progressive hypertrophic obstructive cardiomyopathy (HOCM) and renal tubular dysfunction which improved on continuous subcutaneous infusion of recombinant human insulin-like growth factor-1 (rhIGF-I). INSR gene molecular analysis and insulin receptor (IR) autophosphorylation on cultured fibroblasts were performed. A novel homozygous missense mutation p.Leu795Pro was found, located in the extracellular portion of the β subunit of the insulin receptor. The post-binding defect of the insulin receptor signaling in cultured fibroblasts demonstrated decreased insulin receptor autophosphorylation.

CONCLUSION

Treatment with rhIGF-I partially reversed severe progressive HOCM and renal tubular dysfunction in a patient with Donohue syndrome associated with a novel p.Leu795Pro INSR gene mutation causing a severe decrease in IR autophosphorylation.

Areolar sebaceous hyperplasia with underlying primary duct carcinoma of the breast in a woman with Donohue syndrome (leprechaunism)

Areolar hyperplasia is only reported when exaggerated, and even so, exaggerated areolar sebaceous hyperplasia is rare. We have recently seen a case of areolar sebaceous hyperplasia in a 32-year-old woman with Donohue syndrome (leprechaunism), who also had an invasive ductal carcinoma in the same breast. The patient showed typical "elfin-like" face with wide nostrils and thick lips, large and low-set ears, and dysplastic nails. The areola showed a yellowish thickened plaque of 5-cm diameter that corresponded to a hyperplasia of the sebaceous glands. Immunohistochemistry for the mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) was performed on the sebaceous hyperplasia and on the breast carcinoma, and no lack of expression of the markers was evidenced. We have found no other reported case of areolar sebaceous hyperplasia either in cases of breast carcinoma or in cases of leprechaunism.