If you are viewing Simon's website because you or someone you know has had a similar diagnosis, please feel free to contact me any time at firstname.lastname@example.org. I would love to help you with any questions I can answer or information I can pass on. God Bless . Also, please check out thes website www.benotafraid.net for parents with prenatal diagnoses.
Welcome to the wonderful world of science. Prior to Simon's diagnosis I had that vague knowledge of 9th grade science on how chromosomes work. Now, I'm a little bit more well versed! Probably the most common chromsome disorder is Down Syndrome. How this occurs is there is an extra 21st chromosome in every cell of the body. Pallister-Killian Syndrome is different as it's a mosaicism. A mosaicism is when there is a chromsome anomaly but it is not in each and every cell. Simon has between 55% and 65% of his cells affected. With PKS that is not a direct correlation to the severity of the syndrome. PKS involves chromosome number 12 and it is a tetrasomy not a trisomy (Down Syndrome is a trisomy). People affected with PKS have 2 extra copies of the short arm of chromosome 12 in some of their cells.
This is a picture of Simon's actual chromosomes done at Mayo Clinic. Note where the arrow points to the extra 12's. They are stacked on top of each other, so where it looks like one extra 12, it's really 2 extra parts.
Here are some links to websites regarding Pallister-Killian Syndrome: