Since hemophilia is an X-linked recessive disorder, the probability depends on the X alleles. So, if father has dominant allele (H), the probability that a <span>female child would suffer from hemophilia (genotype: hh) is 0%, no matter of mother's genotype:
Father Mother Parents: H x Hh Daughter: HH or Hh
</span> Father Mother Parents: H x HH <span>Daughter: HH </span> Father Mother Parents: H x hh <span>Daughter: Hh or Hh </span> But, if the father has recessive allele, the probability that a <span>female child would suffer from hemophilia (genotype: hh) will depend on mother's genotype. If mother is dominant homozygous, there will be 0% of possibility: </span> Father Mother Parents: h x HH <span>Daughter: Hh </span> If mother is recessive homozygous, the possibility is 100%: Father Mother Parents: h x hh <span>Daughter: hh </span> If mother is heterozygous, the possibility is 50%: Father Mother Parents: h x Hh <span>Daughter: Hh or hh</span>
The brain in children will have a much more synaptic connection than adults. This connection is important for learning process in the early stage of life. More synaptic connections allow multiple parts the brain areas to be connected even if there is a damage in one area. The synapse will be cut down later in a process called synaptic pruning. Only the area that frequently used will be preserved.
