Transcript Prader-Willi syndrome - Christopher-Bio6

Prader Willi and Angelman
• Failure to inherit a nonimprinted gene on
the father's chromosome #15 causes a
human congenital disorder called PraderWilli syndrome.
• Failure to inherit one nonimprinted gene
(UBE3A) on the mother's chromosome
#15 causes Angelman syndrome.
Prader WIlli
Syndrome
Angelman
Syndrome
Paternal Chromosome
The “A” gene is silence on all paternal
chromosomes, while the “B” gene is silenced
on all maternal chromosomes.
So, this child lives their life with what
phenotype?
Maternal Chromosome
Now this child is old enough to become a father. In each
of his sperm cells…The old imprints are removed.
His spermatogium go through meiosis to form four haploid sperm
cells…that look like the following.
New Imprints are then added…Upon which allele do the imprints
get added because we are dealing with a FATHER??
What if the original chromosome was a girl?
Meiosis occurs…..
New Imprints are put on….
If boy meets girl….