New study looks at DNMT3A mosaicism

Dr. Ayala Tovy, a researcher at Baylor College of Medicine and a medical advisory board member of The TBRS Community, and her colleagues have described an individual who has what’s known as DNMT3A mosaicism. This means that the person has one DNMT3A sequence in some cells and another DNMT3A variant sequence in other cells, since he was an embryo. One of the sequences represents a healthy gene, while the other causes TBRS if present in every cell. Because the man’s sperm is mosaic—that is, some cells have the healthy sequence and some have the variant sequence—four of his children have TBRS and 10 of his children do not.Dr. Tovy’s group found that the TBRS-related variant was present in every sample taken of the blood, but only rarely evident in other tissue types. In other tissues, the healthy sequence was predominant. This might mean that the TBRS variant has a particular advantage in the blood, a concern given that DNMT3A variants are common in the white blood cells of patients with leukemia (these patients are not born with the variant, but their cells later pick it up, which drives the development of cancer). The mosaic individual does not have a history of leukemia, which indicates that DNMT3A variants in the blood are not a guarantee for developing the cancer.Read their study here: https://pubmed.ncbi.nlm.nih.gov/32673568/