Genetic Disorder Introduction: Genetic Disease or disorder is a change that occurs in each individual’s DNA that makes up the gene. A disorder results when a gene is mutated and the protein product can no longer perform its normal function. They can be inherited because they are a change in the germ cells which passes the genetic information from parents to its offspring. Also it can have changes in the DNA in somatic cells or in other body cells; mostly it doesn’t has to be the in germ cells. These disorders are caused by the mutations in the sequence of single gene. Most of the genetic diseases are multifactorial which caused by the mutations in many other genes lead by the environmental issues. Such as heart diseases, cancer and diabetes.
Is Haemophilia inherited or not: Haemophilia is inherited in the pattern of X-linked. This is because when gene mutation occurs is located in the X chromosome which is one of the two sex chromosomes. In males who have only one X chromosome and one copy of the gene is enough to cause the genetic condition. However, in females who have two X chromosomes mutation must occur in the both copies of the genes to cause haemophilia. The crucial characteristic of X lined inheritance is that males cannot pass down their X- linked traits to their sons. For example if a female is a carrier, she has one in two precent to pass on her X chromosomes with the gene mutation for haemophilia A or B to a boy. Whereas, she might not be able to pass the X chromosome to her boy with the normal functioning gene. So above all, she has a fifty percent of chance of infecting her child of haemophilia.
Inheritance of haemophilia: This disease is inherited condition which occurs in family, whereas in one third of cases show it appears in families with no previous history of the haemophilia disorder. Basically the genetic process causing haemophilia is passed down to generation to generation. For example, males with haemophilia will pass the altered gene to their daughters but not to their sons. But with women who carry altered gene can pass it to their sons or daughters. This will result in sons having this genes will have haemophilia but with daughters who carry this genes will also experience bleeding problems.

On the other side of inheritance of haemophilia the genes factors are VII and IX. They are located on the X- chromosome. Males with the altered factor VII or IX gene on their X chromosomes will obtain haemophilia. Such as males having haemophilia gene will pass down to their daughters because he has passed his altered factor of VIII or IX on them. But his sons will not have haemophilia because the Y gene is passed down to them. In female situation, who are carrying haemophilia their sons will have fifty percent of chance having and other fifty percent of chance for daughters carrying the haemophilia gene. In pregnancy, these percentages stay the same.

Sex Determination:
Before the inheritance of haemophilia every person has a pair of sex chromosome and each parent passes one chromosome to their child. Females have two X-chromosomes and receive one from each parent. With males they have one Y chromosome received from their mother and X-chromosome received from their father. This clearly concludes that the father’s chromosomes can predict their child’s gender.
Cells and chromosomes: Human body is made up of millions of cells and there are forty six chromosomes arranged in pairs in the nucleus. The genetic information is in their chromosome. They determine the individual’s hair or eye colour.

What genes are related to haemophilia?