A novel selective deletion of the major α‐globin regulatory element (MCS‐R2) causing α‐thalassaemia

A Severe Case of Hemoglobin H Disease due to Compound Heterozygosity for Deletion of the Major α-Globin Regulatory Element (MCS-R2) and α0-Thalassemia

“…This detected a heterozygous deletion of MCS-R2. Further investigation of deletion breakpoints showed that the 742-bp deletion upstream of the α-cluster removes the MCS-R2 element, consistent with the (αα) JX allele [3]. Family studies confirmed that the patient inherited the (αα) JX allele from the mother and the SEA deletion from the father.…”

“…The main function of MCS-R2 in the normal chromosomal environment is to activate and enhance the expression from the ζ and the α promoters [2]. Recently, we reported a Chinese family with α-thalassemia due to a deletion of only the MCS-R2 [(αα) JX ] [3]. The carriers presented with hematological characteristics as that of α⁰-thalassemia.…”

A combination of the (αα)GZ and ‐‐SEA deletions causing a severe form of hemoglobin H disease

“…3,4 Deletion of α-globin genes combined with HS-40 deletions causing Hb H diseases is rare and helps us understand HS-40 features. 5,6 Here, we describe a novel deletion located in the HS-40 region in the α-globin gene cluster in a 3-year-old girl from Ganzhou City, Jiangxi Province of southern China, who showed severe anemia symptoms at 3 months and needed a blood transfusion every 45-50 days to maintain normal life activities. She also had hepatosplenomegaly.…”

Genetic Background of β Thalassemia Modifier: Recent Update

“…25 The balance abnormalities of α and β chains on β thalassemia are also related with major α globin gene regulator. Homozygous deletion on these regulator may produce Hb H disease appearance, 26,27 but in coinheritance with β thalassemia could modify α and β chain ratio, impacting to a better condition. 28…”