Current status of thalassemia in minority populations in Guangxi, China

Abstract

Thalassemia is one of the most common monogenic disorders in the world. In order to develop a community-based prevention program, we screened 12,900 individuals for alpha- and beta-thalassemia in Baise City, Guangxi, China, with hematological methods and molecular assays. We found that the frequency of carriers in this area for alpha-thalassemia is 15%. Beta-thalassemia carriers comprise 4.8% of the populations. Five mutations account for 98% of alpha-thalassemia [--SEA 46.7%; -alpha/4.2, 23.9%; -alpha/3.7, 21.7%; hemoglobin (Hb) Constant Spring, 6.5%; Hb Quong Sze, 1.1%]. Seven mutations in the beta-globin gene account for 99% of the mutations [codon (CD) 41/42 (-TCTT) (39.4%), CD 17(A-->T) (32%), CD 71/72 (+A) (7.4%), -28 (A-->G) (5.8%), IVS-2-654 (C-->T) (5.8%), CD26 (Hb E) (4%), IVS-1 (G-->A) (3.7%), and CD 43(G-->T) (1.9%)]. Most individuals with alpha-thalassemia major die in the uterus or shortly after birth. Among 106 patients with beta-thalassemia major followed by our clinic, the majority died before 5 years of age. Knowledge surveys about thalassemia were conducted. Our results show a severe lack of knowledge about thalassemia in both medical professionals and in the general populations. This study shows that thalassemia is a very severe public health issue in minority populations in Baise City, China. Identification of the common mutations will allow us to design cost-effective molecular tests. There is an urgent need to educate the general population and the medical community for a successful community-based prevention program.

A Melting Curve Analysis–Based PCR Assay for One-Step Genotyping of β-Thalassemia Mutations

“…3,4 In China, the estimated incidence of carriers of ␤-thalassemia is as high as 7% in the Guangxi Province, and 1% to 6% in populations elsewhere in the endemic areas of southern China. [5][6][7][8] ␤-Thalassemia is a severe disease, and its treatment requires many resources, both medical and financial. While many cities in China have facilities for diagnosis and treatment of this disease, free medical services are not provided by the government in most rural areas.…”

“…To date, 45 single-nucleotide mutations and small deletions in HBB have been detected in the Chinese population. [5][6][7][8][9][10] Translation of the data into clinical practice requires a simple, reliable, cost-effective method that is able to detect all of these mutations. Among dozens of methods that have been developed for detecting ␤-thalassemia mutations, [11][12][13] reverse dot blot (RDB) analysis is the only method approved in China.…”

Frequency of Red Cell Alloimmunization Among Patients with Transfusion Dependent Beta Thalassemia in Pakistan

“…1,2 The term thalassemia comes from a Greek word "thalas" which means the sea, and "emia" that stands for blood. 3,4 The composite word came into use because this type of anemia was originally described in countries bordering the Mediterranean Sea.…”

Development and validation of a ζ-globin-specific ELISA for carrier screening of the (−−SEA) α thalassaemia deletion

“…This monogenic disease mainly results from gross deletions of the human α-globin gene cluster on chromosome 16p13.3. Although non-deletional forms of the defect have been increasingly identified, the Southeast Asian deletion (SEA deletion or (−− SEA ) deletion) is the commonest cause of α thalassaemia in SEA countries including South China, and the estimated heterozygous carrier frequency among SEA populations ranges from 4.5% to 14.0% 2 – 4. In regions of SEA, the homozygous form of the SEA deletion can cause Hb Bart’s hydrops fetalis, which results in fetal death and is associated with serious maternal complications.…”