Is Thanatophoric Dysplasia hereditary?
Thanatophoric Dysplasia (TD) is a severe skeletal disorder that affects the development of bones in a fetus. It is a rare genetic condition that leads to severe skeletal abnormalities and is usually fatal shortly after birth. TD is caused by mutations in the FGFR3 gene, which is responsible for producing a protein involved in bone development and growth.
Genetic Basis of Thanatophoric Dysplasia
TD is primarily caused by de novo mutations, meaning that it occurs spontaneously in the affected individual and is not inherited from the parents. These mutations can occur during the formation of reproductive cells (eggs or sperm) or early in embryonic development. In most cases, the parents of a child with TD do not have the condition themselves and are not carriers of the mutated gene.
Autosomal Dominant Inheritance
However, in rare cases, TD can be inherited in an autosomal dominant manner. Autosomal dominant inheritance means that a single copy of the mutated gene is sufficient to cause the condition. In these cases, one of the parents carries the mutated FGFR3 gene and has a 50% chance of passing it on to each of their children. If a child inherits the mutated gene, they will have TD.
Genetic Testing and Counseling
Genetic testing can be performed to identify the specific mutation in the FGFR3 gene that causes TD. This can help determine the mode of inheritance and provide information for genetic counseling. Genetic counseling is recommended for individuals or families affected by TD to understand the risks of recurrence and the available options for family planning.
Reproductive Options
For families with a child affected by TD, the risk of having another child with the condition depends on the specific genetic cause. If the TD is caused by a de novo mutation, the risk of recurrence is low. However, if the TD is caused by an inherited mutation, the risk of having another affected child is higher.
Prenatal Diagnosis
Prenatal diagnosis is possible for families at risk of having a child with TD. This can be done through genetic testing of fetal cells obtained through procedures such as chorionic villus sampling or amniocentesis. Prenatal diagnosis allows parents to make informed decisions about the continuation of the pregnancy and to prepare for the care of a child with TD if desired.
Conclusion
In summary, Thanatophoric Dysplasia is primarily caused by de novo mutations in the FGFR3 gene and is not usually inherited from parents. However, in rare cases, TD can be inherited in an autosomal dominant manner. Genetic testing and counseling are important for families affected by TD to understand the specific genetic cause, assess the risk of recurrence, and make informed decisions about family planning.