Heredity thought to be the cause
Although the disease is very rare, it nevertheless seems to occur at a higher frequency in the French-Canadian population of Quebec. According to the research, this population is affected more than any other population group in the world. The condition seemed to be most probably of genetic origin, since in some families more than one child is born with the condition. This suggests recessive heredity, which is carried by the parents. "We have discovered that a number of children born with MIA carry the same genetic mutation from both parents. This finding confirms the recessive disease hypothesis that the mutation is inherited from both the father and the mother. As they do not suffer from the disease and do not know that they can transmit the mutation. The identification of the defective gene (TTC7A) makes it possible for us to know the cause of the condition. This is excellent news both for Quebec families with the disease and families around the world where the mutation is present," confirms Vincent Raymond, co-author of the study and a researcher at the CHU de Qubec Research Center.
Screening tests for pregnant women and family members who are potential carriers
Couples with an MIA child have a 25% risk of recurrence in subsequent pregnancies. "The concept of prenatal diagnosis allows couples to proceed with tests at the beginning of the pregnancy to determine whether the child they are expecting will be affected. We can also, within the same family, determine whether, for example, siblings are carriers of this genetic condition, and eventually, whether their partner is at risk in order to predict the risk of recurrence in the following generations," stresses Dr. Maranda, the study's principal investigator and Head of the Department of Medical Genetics at the CHUS.
|Contact: Mathieu Filion|
University of Montreal