Thalassemia Lecture Series (2) The Genetic Law of Thalassemia2014-06-12Southern Hospital Prenatal DiagnosisSouthern Fetal MedicineJia Bei, Department of Obstetrics and Gynecology, Southern Hospital of Southern Medical UniversityThe genetic law of thalassemia – autosomal recessive inheritance (not related to gender, male and female fetuses have equal chance of developing thalassemia)1, if both husband and wife do not carry the gene for thalassemia, the next generation will not develop thalassemia. 2, if one of the spouses is a carrier of thalassemia, the next generation has 1/2 probability of being a carrier of thalassemia gene and 1/2 is completely normal. 3, if both spouses are carriers of the same type of thalassemia gene, the next generation has 1/2 probability of being a carrier of thalassemia (same as one of the parents with thalassemia gene), 1/4 is completely normal and 1/4 carries both parents’ thalassemia gene. If both parents are carriers of the heterozygous thalassemia gene, their next generation will have a probability of 1/2 to be carriers of mild thalassemia (same parent with thalassemia gene), 1/4 to be normal, and 1/4 to carry both parents’ thalassemia gene, but because the parents are not homozygous for thalassemia, we call them αβ compound thalassemia carriers, with the same clinical manifestations as mild thalassemia. Comparison of screening and diagnostic methods for thalassemia screening: At present, clinical screening for thalassemia is mainly done by routine blood tests and hemoglobin electrophoresis, which are simple and inexpensive, but have a certain risk of missing the diagnosis. Confirmation of the diagnosis of thalassemia still relies on genetic diagnosis. Genetic diagnosis of thalassemia – the gold standard of thalassemia diagnosis: Genetic testing is the only means to confirm the diagnosis of thalassemia, and it can clarify the type of mutation of the thalassemia gene. However, the genetic diagnostic kits currently available in the market can only detect about 95% of the common types of genetic mutations in leukodystrophy, especially couples with positive screening and negative genetic diagnosis may have rare types of leukodystrophy mutations, and the underdiagnosis of such mutations increases the risk of birth of children with severe leukodystrophy. For this group of people, our center carries out genetic testing for rare forms of thalassemia to contribute to the reduction of births of children with severe thalassemia. Advantage☆ It is the ultimate method and gold standard for confirming the diagnosis of thalassemia. It can detect carriers of the gene for mild cases of thalassemia and help prevent the birth of children with severe thalassemia. ☆ Determining the patient’s genotype can be used for genetic counseling to guide prenatal diagnosis on the one hand; on the other hand, it can predict the risk of developing thalassemia in family members based on the genotype and guide marriage and childbirth. Report