Holoprosencephaly has no single cause, but about half of all cases are associated with abnormal karyotype (abnormal numbers of chromosomes), especially trisomy 13 (extra copy of chromosome 13) and trisomy 15 (extra copy of chromosome 15).
In one kind of abnormal chromosome inheritance called Down syndrome, a child has three copies of Chromosome 21!
This is exactly how DMD is transmitted: the defect resides on the X chromosome. Women have 2 X chromosomes, so even if one of the X chromosomes has the DMD trait, the other X chromsome does not and they never get DMD. This is why boys exclusively get Duchenne - they have only one X chromosome. So if a woman carries the Duchenne trait, there is a 50% chance that she will pass DMD to her male offspring. Similarly, there's a 50% chance that her daughters will become carriers like her.
chromosome 21
That happens in Ana phase.When a chromosome is not split in centromere,a chromosome fully moves to a daughter cell.
Dystrophin gene / Xp21 gene / DMD gene: Found at locus Xp21 of the X chromosome, this is why it's called the (Xp21 gene) It's the gene responsible for Duchenne muscular dystrophy(DMD) when mutated, this is why it's called (DMD gene)
Incomplete cellular division can lead to the formation of cell fragments or abnormal cells with abnormal chromosome numbers, which can result in genetic abnormalities or cell death. This can lead to impaired tissue function and potentially contribute to the development of diseases such as cancer.
Duchenne affects approximately 1 in every 3500 boys, or 20,000 babies born each year worldwide. Because the Duchenne gene is on the X chromosome, the disorder manifests primarily in boys. In nearly 35% of cases, Duchenne is caused by random genetic mutation.
dmd Ps
primary can happen in meiosis and as a result produces gametes with more than or less than the original number of chromosomes. secondary occur in an individual whose chromosomes already has the wrong number because of non disjunction.
An abnormal number of chromosomes is called aneuploidy. If a chromosome has 3 of its kind, it is trisomic. The exact condition depends on which gene has the extra chromosome.
As a HUGE HSM fan, what is dmd?