Seven Patients With Transcobalamin Deficiency Diagnosed Between 2010 and 2014: A Single-Center Experience.
Transcobalamin deficiency (OMIM 275350) is a rare autosomal recessive disease presenting with nonspecific clinical features in early infancy. We report the clinical and laboratory manifestations of 7 children diagnosed with transcobalamin deficiency. All patients were admitted between 2 and 4 months of age with anemia, thrombocytopenia, and hyperhomocysteinemia. The most common complaints at admission were pallor, weakness, and poor feeding. Genetic analysis was performed in 5 patients and it revealed the same homozygous mutation. We initially treated all patients with intramuscular injections of a maximum of 1 mg cyanocobalamin (CN-Cbl) daily and with a final dose of 1 mg per week. Hemoglobin and platelet counts significantly decreased upon decrease or cessation of CN-Cbl therapy. The patients were reevaluated between 2 and 4 years of age and all had delay in speech and walking. In conclusion, 1 mg of intramuscular CN-Cbl every week suffices for hematological improvement but not for normal neurological development in patients who all had relapse due to decrease or cessation of treatment.
*Division of Pediatric Hematology/Oncology, Faculty of Medicine, Atatürk University, Erzurum §Division of Pediatric Hematology/Oncology, Faculty of Medicine, Sakarya University, Sakarya, Turkey †Department of Clinical Biochemistry, Aarhus University Hospital, Aarhus, Denmark ‡Departments of Biochemistry and Pediatrics, Children's Health Research Institute, University of Western Ontario, London, ON, Canada.
Zuhal K
ZK
Yildirim
Ebba
E
Nexo
Tony
T
Rupar
Mustafa
M
Büyükavci
D000740:Anemia / Q000209:etiology / Q000628:therapy; D018389:Codon, Nonsense; D003131:Combined Modality Therapy; D002658:Developmental Disabilities / Q000209:etiology; D003937:Diagnosis, Differential; D017707:Erythrocyte Transfusion; D005260:Female; D016368:Frameshift Mutation; D006720:Homozygote; D006801:Humans; D020138:Hyperhomocysteinemia / Q000209:etiology; D007223:Infant; D008297:Male; D017713:Platelet Transfusion; D012189:Retrospective Studies; D017384:Sequence Deletion; D013921:Thrombocytopenia / Q000209:etiology / Q000628:therapy; D014155:Transcobalamins / Q000172:deficiency* / Q000235:genetics; D014421:Turkey; D014805:Vitamin B 12 / Q000627:therapeutic use; D014806:Vitamin B 12 Deficiency / Q000175:diagnosis
D018389:Codon, Nonsense; D014155:Transcobalamins; D014805:Vitamin B 12