Transcobalamin II Deficiency in Four Cases with Novel MutationsSule Unal1, Tony Rupar2, Sevgi Yetgin1, Nese Yarali3, Ali Dursun4, Türkiz Gürsel5, Mualla Cetin11Hacettepe University Faculty of Medicine, Division of Pediatric Hematology, Ankara, Turkey
2Victoria Hospital, London Health Sciences Centre, Biochemical Genetics Laboratory, London, Canada
3Ankara Children’s Hematology and Oncology Hospital, Clinic of Pediatric Hematology, Ankara, Turkey
4Hacettepe University Faculty of Medicine, Division of Metabolism and Nutrition, Ankara, Turkey
5Gazi University Faculty of Medicine, Division of Pediatric Hematology, Ankara, Turkey
INTRODUCTION: Transcobalamin II deficiency is one of the rare causes of inherited vitamin B12 disorders in which the patients have characteristically normal or high vitamin B12 levels related to the transport defect of vitamin B12 into the cell, ending up with intracellular cobalamin depletion and high homocysteine and methylmalonic acid levels.
METHODS: Herein, we describe the findings at presentation of four patients who were diagnosed to have transcobalamin II deficiency with novel mutations.
RESULTS: These patients with transcobalamin II deficiency were found to have novel mutations, of whom 2 had the same large deletion (homozygous c.1106+1516-1222+1231del).
DISCUSSION AND CONCLUSION: Transcobalamin II deficiency should be considered in differential diagnosis of any infant with pancytopenia, failure to thrive, diarrhea, and vomiting.
Keywords: Vitamin B12, Transcobalamin II, Novel mutation, Novel deletion, Vacuolizatio
Yeni Mutasyonu Olan Dört Transkobalamin II Eksikliği OlgusuSule Unal1, Tony Rupar2, Sevgi Yetgin1, Nese Yarali3, Ali Dursun4, Türkiz Gürsel5, Mualla Cetin11Hacettepe University Faculty of Medicine, Division of Pediatric Hematology, Ankara, Turkey
2Victoria Hospital, London Health Sciences Centre, Biochemical Genetics Laboratory, London, Canada
3Ankara Children’s Hematology and Oncology Hospital, Clinic of Pediatric Hematology, Ankara, Turkey
4Hacettepe University Faculty of Medicine, Division of Metabolism and Nutrition, Ankara, Turkey
5Gazi University Faculty of Medicine, Division of Pediatric Hematology, Ankara, Turkey
GİRİŞ ve AMAÇ: Transkobalamin II eksikliği nadir bir kalıtsal B12 vitamini bozukluğudur. Defektin B12 vitamininin transportu ile ilgili olması nedeniyle hastalar normal ya da yüksek B12 vitamini düzeylerine eşlik eden yüksek homosistein ve metilmalonik asit düzeylerine sahiptir.
YÖNTEM ve GEREÇLER: Bu çalışmada transkobalamin II eksikliği tanısı alan dört hasta sunulmuştur. Bu hastalarda daha önce bildirilmemiş yeni mutasyonlar saptanmıştır.
BULGULAR: Hastaların ikisinde aynı büyük delesyon olduğu görülmüştür (homozigot c.1106+1516-1222+1231del).
TARTIŞMA ve SONUÇ: Pansitopeni, büyüme geriliği, ishal ya da kusması olan tüm bebeklerde transcobalamin II eksikliği ayırıcı tanıda düşünülmelidir.
Anahtar Kelimeler: B12 vitamini, Transkobalamin II, Yeni mutasyon, Yeni delesyon, Vaküolizasyon
Sule Unal, Tony Rupar, Sevgi Yetgin, Nese Yarali, Ali Dursun, Türkiz Gürsel, Mualla Cetin. Transcobalamin II Deficiency in Four Cases with Novel Mutations. Turk J Hematol. 2015; 32(4): 317-322
Corresponding Author: Sule Unal, Türkiye |
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