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Beta Thalassemia
Published in Charles Theisler, Adjuvant Medical Care, 2023
The signs and symptoms of thalassemia major appear within the first two years of life. Children develop life-threatening hemolytic, microcytic, and hypochromic anemia‘ which can cause pale skin, weakness, fatigue, poor growth, and skeletal abnormalitiess. Individuals with this disorder are at an increased risk of developing abnormal blood clots.1
Carrier Screening For Inherited Genetic Conditions
Published in Vincenzo Berghella, Obstetric Evidence Based Guidelines, 2022
Whitney Bender, Lorraine Dugoff
Beta-thalassemia is also caused by a mutation in the beta-globin gene on chromosome 11. This results in the inability to produce hemoglobin A. Individuals who are heterozygous for this mutation have beta-thalassemia minor. Depending upon the amount of normal beta-globin chain production, disease severity varies. Typically, asymptomatic mild anemia is present. Individuals who are homozygous for this mutation have beta-thalassemia major, or Cooley anemia. This disease is characterized by severe anemia with extramedullary hematopoiesis, delayed sexual development, and poor growth. Although elevated levels of Hb F are produced in an attempt to compensate for the absence of Hb A, this condition is universally fatal in late childhood unless treatment with periodic blood transfusions is initiated early. See Chap. 14 in Maternal-Fetal Medicine Evidence Based Guidelines.
Chorionic villus sampling
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Giovanni Monni, Maria Angelica Zoppi, Carolina Axiana
The purpose for prenatal diagnosis of genetic disorders is to determine the carrier status in order to help with genetic counseling of at-risk couples. Most carrier recognition and genetic counseling are retrospective, that is, after the birth of an affected child. Nonetheless, several programs related to carrier screening have been launched for populations known to be at risk for specific disorders, as is the case of beta-thalassemia in the Mediterranean area. Beta-thalassemia is the most common single-gene disorder among Italians, where 13% of the people on the Sardinia Island are healthy carriers. Ongoing programs of screening have proved quite effective, and they have resulted in a noticeable decline in the incidence of thalassemia major. Screening programs for Sardinians are based on carrier detection by employing hematologic methods, and genetic diagnoses can be made by identifying specific mutations through DNA analysis in carrier couples. In this way, prenatal diagnosis can be accomplished by mutation analysis on PCR-amplified DNA from chorionic villi (31). Because of advances in molecular techniques, the number of single-gene disorders offered for wide-based population screening will undoubtedly grow.
Detection of a Rare Mutation in the Initiation Codon of the β-Globin Gene (HBB:C.2T > C; P.Met1Thr)
Published in Hemoglobin, 2023
Rawand Shamoon, Ahmed Yassin, Amir Charkaneh
An 11-year-old male proband with transfusion-dependent β-thalassemia was referred to the Genetics unit of PAR hospital lab in Erbil city for genetic testing to explore the mutations in the β-globin gene. The case was diagnosed as β-thalassemia major based on the routine clinical and hematological features as well as the Hb chromatography. The proband had typical thalassemic facies and moderate splenomegaly; he was on regular blood transfusion and iron chelation therapy. His parents’ red cell indices and chromatography were typical of the β-thalassemia trait. The proband was initially tested for 22 common β-globin gene mutations by PCR and reverse hybridization. Only one β0 mutation was detected which did not justify the proband’s clinical phenotype. The proband’s parents were therefore tested separately using the same method to double-check the results. The mother was found to carry the same mutation that was previously detected in the proband, while no mutation was detected in the father’s DNA sample. Therefore, we referred the samples of the proband and his father to a referral lab to perform Sanger sequencing for both samples. The proband as well as his parents were additionally screened for 21 common mutations/deletions in the α-globin genes using PCR and reverse hybridization.
An Expert Overview on Therapies in Non-Transfusion-Dependent Thalassemia: Classical to Cutting Edge in Treatment
Published in Hemoglobin, 2023
Mohammadreza Saeidnia, Pooria Fazeli, Arghavan Farzi, Maryam Atefy Nezhad, Mojtaba Shabani-Borujeni, Mehran Erfani, Gholamhossein Tamaddon, Mehran Karimi
β-Thalassemia intermedia (β-TI) was first described by Rietti-Greppi Micheli in 1955 [2]. The disease features milder clinical symptoms than β-thalassemia major (β-TM). The follow-up of patients with β-TI is usually in late childhood or even adulthood. Because the patients with β-TI display mild to intermediate levels of anemia (Hb levels: 7.0–10.0 g/dL) and generally do not require regular transfusions except in specific clinical conditions, such as pregnancy, infection, and surgery, this type of thalassemia is also referred to as non-transfusion-dependent thalassemia (NTDT). Therefore, the patient’s clinical status evaluation more important for controlling the disease’s detrimental effects, better apprehending the myriad aspects of its pathophysiology, and also could be profitable for extending patients’ longevity and quality of life [1,3–6].
Research Progress of Cell-Free Fetal DNA in Non-Invasive Prenatal Diagnosis of Thalassemia
Published in Hemoglobin, 2023
Dewen Liu, Chen Nong, Fengming Lai, Yulian Tang, Taizhong Wang
Thalassemia is a common hemolytic disease caused by abnormal globin synthesis due to mutations or deletions of HBA1, HBA2 or HBB genes, resulting in abnormal morphology and life cycle of red blood cells. The Globin website (https://globin.bx.psu.edu/cgi-bin/hbvar/counter) currently records more than 500 types of thalassemia mutations and deletions. Thalassemia is also a hereditary autosomal global disease; globally, an estimated 270 million people suffer from or carry abnormal hemoglobin and thalassemia [1]. Generally, the clinical symptoms of thalassemia carriers are mild, or even indistinguishable from those of healthy individuals. However, if both couples are carriers of thalassemia, then each time the fetus is born, there is a 1/4 chance of developing thalassemia major. There is no effective cure for thalassemia major except for bone marrow transplantation. Therefore, in areas with a high prevalence of thalassemia, prenatal diagnosis is the most effective means and method to reduce the number of newborns with thalassemia major. Invasive prenatal diagnosis is a common method for the diagnosis of thalassemia at present. Invasive procedures include amniocentesis, chorionic villi sampling, or umbilical cord blood sampling, all of which are traumatic and can cause vaginal bleeding, cervical abnormalities, and an increased risk of fetal infection in pregnant women [2–4], and ultrasound-assisted sampling is needed.