Catecholamine-induced Myocarditis in a Child with Pheochromocytoma

Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumors. The clinical presentation of pediatric PPGLs is highly variable. In cases with pheochromocytoma (PCC), excess catecholamine may stimulate myocytes and cause structural changes, leading to life-threatening complications ranging from stress cardiomyopathy (CM) to dilated CM. Herein, we report the case of catecholamine-induced myocarditis in a child with asymptomatic PCC. A 12-year-and-2-month-old male patient with a known diagnosis of type-1 neurofibromatosis was brought to the emergency department due to palpitations and vomiting. On physical examination, arterial blood pressure was 113/81 mmHg, pulse was 125/min, and body temperature was 36.5 °C. Laboratory tests showed a leucocyte count of 12.8x103 µL/L and a serum C-reactive protein level of 1.1 mg/dL (Normal range: 0-0.5). Thyroid function tests were normal, while cardiac enzymes were elevated. Electrocardiogram revealed no pathological findings other than sinus tachycardia. The patient was diagnosed with and treated for myocarditis as echocardiography revealed a left ventricular ejection fraction of 48%. Viral and bacterial agents that may cause myocarditis were excluded via serological tests and blood cultures. Blood pressure, normal at the time of admission, was elevated (140/90 mmHg) on the 5th day of hospitalization. Magnetic resonance imaging revealed a 41x46x45 mm solid adrenal mass. The diagnosis of PCC was confirmed by elevated urinary and plasma metanephrines. The patient underwent surgery. Histopathology of the excised mass was compatible with PCC. It should be kept in mind that, even if there are no signs and symptoms of catecholamine elevation, CM may be the first sign of PCC.

A Rare Etiology of 46,XY Disorder of Sex Development and Adrenal Insufficiency: A Case of MIRAGE Syndrome Caused by Mutations in the SAMD9 Gene

Adrenal hypoplasia is a rare congenital disorder. In spite of biochemical and molecular genetic evaluation, etiology in many patients with adrenal hypoplasia is not clear. MIRAGE syndrome is a recently recognized congenital disorder characterized by myelodysplasia, infection, growth restriction, adrenal hypoplasia, genital phenotypes, and enteropathy. Here we present a case of MIRAGE syndrome due to a heterozygous missense variant (c.2920G>A; p.E974K) mutation in the sterile alpha motif domain-containing protein-9 (SAMD9) gene. This report describes the first MIRAGE syndrome patient in Turkey.

Enzyme Replacement Therapy in Hypophosphatasia

Hypophosphatasia (HPP) is associated with significant morbidity and mortality in pediatric patients. The disease also imposes a high disease-burden in adult-onset HPP. Asfotase alfa (AA) is the first-in-class, bone-targeted, enzyme- replacement therapy designated to reverse the skeletal mineralisation defects in HPP. A male newborn presented with extreme fontanel gap and respiratory distress. He was diagnosed with perinatal lethal HPP thus AA treatment was started. Serum alkaline phosphatase (ALP) levels increased as high as 12,700 U/L during treatment. Any side effect related to AA was not observed. AA may be a valuable emerging therapy for the treatment of HPP.