Pınar Haznedar, F. Tuba Eminoğlu

Gözden kaçabilecek ve tedavi edilebilir bir hiperinsülinemik hipoglisemi olgusu: konjenital glikozilasyon defekti Tip Ib

Konjenital glikozilasyon defektleri (CDG) otozomal resesif kalıtım gösteren, gelişme geriliği, hipotoni ve multisistem tutulumla seyreden hastalıklardır. Konjenital Glikozilasyon Defekti Tip 1b fosfomannoz izomeraz enzimindeki eksikliğe bağlı oluşmaktadır. Diğer glikozilasyon defektlerinin aksine, özellikle hepatik ve gastrointestinal bulgularla seyretmektedir. Nörolojik tutulum gözlenmez ve etkilenmiş bireylerin zekâ seviyeleri normaldir. Bu raporda, 10 aylıkken ishal, kusma, büyüme-gelişme geriliği ve hepatosplenomegali nedeniyle önce hiperinsülinemik hipoglisemi tanısı ile diazoksit tedavisi başlanan ve tedaviye yanıt alınamaması nedeniyle merkezimize yönlendirilen bir olgu sunulmaktadır. Klinik ve laboratuvar bulguları konjenital glikozilasyon defekti tip Ib ile uyumlu olan hastaya D-mannoz tedavisi başlandı. Tedaviye dramatik yanıt veren hastanın semptomları iki hafta içerisinde geriledi. Konjenital Glikozilasyon Defekti Tip 1b yeni tanımlanmaya başlamış, D-mannoz tedavisinden belirgin fayda gören bir metabolik hastalıktır. Gastrointestinal semptomlar, hipoglisemi, hepatosplenomegali, karaciğer fonksiyon testlerinde anormallik saptanan ve gelişme geriliği olan olgularda akılda tutulması ve ayrıcı tanıda düşünülmesi önemlidir.

An overlooked case of a treatable hyperinsulinemic hypoglycemia: congenital glycosylation defect Type Ib

Congenital glycosylation defects are autosomal recessive disorders clinically characterized with growth retardation, hypotoniaand multisystemic involvement. Congenital glycosylation defect type Ib is due to deficiency in phosphomannose isomerasewhich converts fructose-6-phosphate into mannose-6-phosphate.Patients usually present with hepatic or gastrointestinal symptoms lacking cranial involvement, making their IQ completelynormal. We report a 10-month-old female patient referred to ourclinic with persistent hypoglycemia, failure to thrive and hepatosplenomegaly who was diagnosed with congenital glycosylation defect type Ib. Oral D-mannose therapy was initiated shortlyafter diagnosis and her symptoms resolved in two weeks. Congenital glycosylation defect type Ib is an easily treatable diseaseand should be kept in mind in differential diagnosis in childrenand adults who show gastrointestinal symptoms, hyperinsulinemic hypoglycemia, palpable liver and spleen, growth retardationand elevated liver function tests.

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1. Jaeken J, Matthijs G, Saudubray JM, et al. Phosphomannose isomerase deficiency: a carbohydrate-deficient glycoprotein syndrome with hepatic-intestinal presentation. Am J Hum Genet 1998; 62: 1535–9.[CrossRef ]
2. Marques-da-Silva D, Dos Reis Ferreira V, Monticelli M, et al. Liver involvement in congenital disorders of glycosylation (CDG). A systematic review of the literature. J Inherit Metab Dis 2017; 40: 195–207. [CrossRef ]
3. Jaeken J. Congenital disorders of glycosylation. Ann N Y Acad Sci 2010;1214: 190–8. [CrossRef ]
4. de Lonlay P, Seta N. The clinical spectrum of phosphomannose isomerase deficiency, with an evaluation of mannose treatment for CDG-Ib. Biochim Biophys Acta 2009; 1792: 841–3. [CrossRef ]
5. Niehues R, Hasilik M, Alton G, et al. Carbohydrate-deficient glycoprotein syndrome type Ib. Phosphomannose isomerase deficiency and mannose therapy. J Clin Invest 1998; 101: 1414–20. [CrossRef ]
6. Mention K, Lacaille F, Valayannopoulos V, et al. Development of liver disease despite mannose treatment in two patients with CDG-Ib. Mol Genet Metab 2008; 93: 40–3.
7. Nessa A, Rahman SA, Hussain K. Hyperinsulinemic Hypoglycemia - The Molecular Mechanisms. Front Endocrinol (Lausanne) 2016; 7: 29. [CrossRef ]
8. Lefeber DJ, Morava E, Jaeken J. How to find and diagnose a CDG due to defective N-glycosylation. J Inherit Metab Dis 2011; 34: 849–52. [CrossRef ]
9. Liem YS, Bode L, Freeze HH, Leebeek FW, Zandbergen AA, Paul Wilson J. Using heparin therapy to reverse protein-losing enteropathy in a patient with CDG-Ib. Nat Clin Pract Gastroenterol Hepatol 2008;5: 220–4. [CrossRef ]
10. Janssen MC, de Kleine RH, van den Berg AP, et al. Successful liver transplantation and long-term follow-up in a patient with MPI-CDG. Pediatrics 2014; 134: e279–83.