X-linked disease

X-linked disease

1. X-LINKED DISEASES

2. Chromosome DNA (hereditary particle) Protein Human cell has 46 chromosomes(23 pairs)

3. Gene (DNA sequence) mRNA Proteins (causes traits) Genes on DNA of chromosome encode traits

4. 1. X chromosome has 2000 genes. 2. X-linked Disease: Disease caused by mutation of gene on X chromosome. Sex chromosome(1 heterozygous pair XY) Chromosome Autosome(22 homozygous pairs)

5. X-linked disease X-linked dominant disease X-linked recessive disease X- linked dominant disease: causes disease when being homozygous and heterozygous of affected mutant chromosome. 1 . Appear in same proportion in male and female. 2 . One X chromosome having mutation can cause disease. 3 . Female both homozygous and heterozygous for mutant X- chromosome are affected. 4.All daughters of affected father.

6. Inheritance of X-linked dominant disease:

7. Some X-linked dominant diseases: 1. X-linked hypophosphatemia: is an X-linked dominant form of rickets (or osteomalacia ). It can cause bone deformity including short stature. It is associated with a mutation in the PHEX gene. An osteotomy may be performed to correct the leg shape.

8. 2. Rett syndrome: is a rare genetic postnatal neurological disorder of the grey matter of the brain . 3. Alport syndrome : is a genetic disorder affecting around 1 in 50,000 children characterized by end-stage kidney disease, and hearing loss . 4. Incontinentia pigmenti : is a genetic disorder that affects the skin, hair, teeth, nails, and central nervous system. It is named due to its microscopic appearance.

9. Prognosis: 1.As genetic disease, these diseases are less curable. 2.Osteotomy(hypophosphatemia),occupational therapy( Rett syndrome) etc. can be performed to recover deform structures and parts. 3.Can be prevented by affected person not having offspring with affected but it can’t be stricked as being parent is a sensitive issue.

10. X-linked recessive diseases: causes disease when only homozygous of mutant chromosome. 1.cause disease in male in more proportion than female. 2.needed 2 mutant X chromosome to cause disease. 2.heterozygous female are carrier of these disease. 3.all sons of a affected mother are affected. 4.in some diseases heterozygous show some degree of disease because of differences in X chromosome inactivation. 5.more common than X-linked dominant diseases.

11. Inheritance of X-linked recessive diseases:

12. Some X-linked recessive diseases : 1. Color blindness: is the decreased ability to see color or differences in color. The most common cause of color blindness is due to a fault in the development of one or more of the three sets of color sensing cones in the eye.

13. 2. Haemophilia A : Haemophilia A is a genetic deficiency in clotting factor VIII, which causes increased bleeding and usually affects males. In terms of the symptoms of Hemophilia A there are internal or external bleeding episodes . 3. Haemophilia B: is a blood clotting disorder caused by a mutation of the factor IX gene, leading to a deficiency of factor IX. It is the second-most common form of haemophilia , rarer than haemophilia A. The condition is marked by increased clotting time(3-8 minutes) and bleeding time(2-5 minutes ).

14. 4. Duchenne muscular dystrophy: Duchenne muscular dystrophy (DMD) is an X-linked recessive form of muscular dystrophy, affecting around 1 in 3,600 boys, which results in muscle degeneration and premature death . The disorder is caused by a mutation in the gene dystrophin . 5. Glucose-6-phosphate dehydrogenase deficiency : s an X-linked recessive inborn error of metabolism that predisposes to hemolysis. Causes jaundice in response to a number of triggers, such as certain foods, illness, or medication.

15. Prognosis : 1.As genetic disease , these diseases are less curable. 2. Lenses(Color Blindness ), regular supplementation with intravenous recombinant or plasma concentrate Factor VIII(Hemophilia A), intravenous infusion of factor IX ( Hemophilia B ) etc. can be taken. 3.There no permanent cure of these disease. 4.Can be prevented by affected person or carrier not having offspring but it can’t be strict as being parent is a sensitive issue . 5.Gene therapy at prenatal stage is an upcoming solution.

16. Gene therapy

17. 1. Awareness about these diseases must spread among people. 2. If possible , should avoid taking offspring. Adoption and others possible ways can be taken to have children. 3. Possible cure of diseases available should be taken. 4. Gene therapy at prenatal state can be used and can be a great cure. 5. Research on gene therapy should be widespread. Conclusion

18. Thank you.