Epidemiologic and clinical characteristics of nontransfusion-dependent thalassemia in the United States

Elliott Vichinsky*, Alan Cohen, Alexis A. Thompson, Patricia J. Giardina, Ashutosh Lal, Carole Paley, Wendy Y. Cheng, Nora McCormick, Medha Sasane, Ying Qiu, Janet L. Kwiatkowski

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

19 Scopus citations

Abstract

Background: Nontransfusion-dependent thalassemia (NTDT) refers to a diverse group of thalassemia mutations and clinical phenotypes that do not require chronic transfusions. It is increasingly prevalent in the United States. Procedure: This study reviews the epidemiology and clinical characteristics of 138 patients with NTDT treated at four US thalassemia centers from 1997 to 2014. Data on laboratory results, transfusions, and clinical complications were collected from patient charts. Results: Overall, 84 patients with α-thalassemia (62 deletional hemoglobin H; 22 nondeletional hemoglobin H), 39 with β-thalassemia (26 with homozygous or double heterozygous β mutations; 13 with single β mutations with or without α triplication), and 15 with E/β-thalassemia (12 E/β 0 ; three E/β + ) were identified. At study entry, the median age for patients with α-thalassemia was 2.3 years; 9.2 years for patients with β-thalassemia and 2.2 years for patients with E/β-thalassemia. Most patients with α-thalassemia were Asian. Patients with β-thalassemia were predominantly Caucasian (46%) or of African descent (36%). Twenty percent of patients were born outside the United States and 5% were transfused before immigration. Complications varied by genotype and age. Individuals with nondeletional hemoglobin H were severely affected and, despite their young age, had many complications. Iron overload increased with age and was more common in patients who received transfusions. Conclusions: NTDT in the United States is a multi-ethnic disease with different genotypic mutations and phenotypic manifestations. A higher than expected proportion of patients was Black/African American. NTDT-related complications are common and increase with age, supporting a need for early diagnosis.

Original languageEnglish (US)
Article numbere27067
JournalPediatric Blood and Cancer
Volume65
Issue number7
DOIs
StatePublished - Jul 2018

Funding

E.V. has received research funding from Novartis Pharmaceuticals Cor-porationandApoPharmaInc.J.L.K.servesasaconsultanttoIonisPhar-maceuticals, Agios Pharmaceuticals, and bluebird bio, and has received research funding as a co-investigator from Novartis Pharmaceuticals Corporation, Agios Pharmaceuticals, Apopharma, Inc., and bluebird bio. A.A.T. serves as a consultant to Novartis Pharmaceuticals Corporation, Celgene, and bluebird bio, and has received research funding from Novartis Pharmaceuticals Corporation, Baxalta, Amgen, Cel-gene, Mast Therapeutics Inc., and bluebird bio. P.J.G. has nothing to declare. C.P. and M.S. are employees of Novartis Pharmaceuticals Corporation. Y.Q. was an employee of Novartis Pharmaceuticals Corporation at the time of the study. W.Y.C. and N.M. are employees of Analysis Group, Inc., a consulting company that has received research grants from Novartis Pharmaceuticals Corporation. A.C. serves as a consultant to Novartis and Roche and serves on the DSMB for studies sponsored by ApoPharma. A.L. has nothing to declare.

Keywords

  • United States
  • clinical iron overload
  • epidemiology
  • nontransfusion-dependent thalassemia
  • thalassemia trait

ASJC Scopus subject areas

  • Hematology
  • Oncology
  • Pediatrics, Perinatology, and Child Health

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