Japanese researchers have successfully eliminated the extra chromosome responsible for Down syndrome using CRISPR gene editing.
  • dondelelcaro@lemmy.world
    9·
    5 days ago

    trisomy-21 isn’t present in sperm or eggs, it’s a mistake in cell division early in fetal development

    This is incorrect. Non-disjunction (where chromosomes incorrectly separate) typically happens during the formation of egg or sperm. (We know this because most everyone with down syndrome has three different chromosome 21 instead of two identical copies of one chromosome.)

    • protist@mander.xyzEnglish
      91·
      5 days ago

      TIL

      • In the majority of cases, the extra copy of chromosome 21 comes from the mother through the egg.
      • In a small percentage (less than 5%) of cases, the extra copy of chromosome 21 comes from the father through the sperm.
      • In the remaining cases, the error occurs after fertilization, as the embryo grows.