Genetically transmitted diseases

Genetically transmitted diseases.

(GTD)

GTD means the diseases that infect to animal from genetically. That means those disease can be occur to animals by changing of a genes. Those diseases can be infecting by means of the exchange of single genes, exchange of several genes or exchanging of chromosomes. Actually STD really are diseases, only change is, those can’t be treated as normal diseases. That means most of them have no medicines. Although they do not have medicine can control by many ways. Normally those are infected among same family members. Such as from mother to son, from father to son, so, if someone hopes to get married from a family that have a history of GTD he or she must be analyze the pedigree analysis.

The following image you can see a pedigree analysis for Hemophilia disease.

              

                   Categories of genetic diseases        

Chromosomal disorders - those that are caused by Change the number or structural abnormalities of the chromosomes, e.g. Down syndrome, Turner syndrome.

Single gene disorders - Those that are caused by defects of Single/individual genes, such as thalassaemia, hemophilia.

Multifactorial disorders - those that are the result of the recombination effect of genetic factors and environmental factors, ex- diabetes mellitus, hypertension, psychiatric diseases and cancer.

Genetically transmitted diseases

Ex- Cystic Fibrosis, Sickle cell anemia, Huntington’s syndrome, Turner syndrome, Down’s syndrome, Thalassaemia 

                                                Cystic Fibrosis

This disease can be damaged the lungs and digestive system of a person. These disease do not be shown when the person so young. This can be seen when they were adults.  Only homozygous recessive genes can affect that to people. The presence of two mutant genes is needed for CF to appear. Each parent carries one defective gene (g) and one normal gene (G)

                          

Affected genes were given signal to our body to make mucus. That mucus can be infected our lungs, liver……….

                                                                                                         Sickle cell anemia

Sickle cell anemia is a blood disorder affecting hemoglobin production. Hemoglobin is a protein in the blood. Actually that carries oxygen around our bodies. This can pass through parents to children. This is also a GTD. Sometimes changes occur in genes. Normally people have 2 beta globin genes (β Globin). A person may have the sickle mutation in one of their two globin genes. That kind of people has Sickle cell anemia. The people who have this disease can’t transport oxygen in blood quite well. Because their hemoglobin were mutated like  sickles.    

                                                  

                  

                                 Huntington’s syndrome

Huntington’s disease (HD) is a genetically transmitted disorder of the central nervous system. It also calls as brain disorder.  This is causing various parts of the brain of people.  The affected people can’t walk well talk well or think well can’t take a correct decision after thinking. Mostly that was affected to people who are around age 35-50. This is also a gene inheritance. Only Heterozygous can affect that to people. Homozygous dominant and recessive are Normal.

 The following image you can see a pedigree analysis for Huntington’s disease and the pellet square that how to inherit this disease. 

      

                                    Turner syndrome(X0)    

      Affect because of the chromosomal mutation. Normally human have 23 pair of chromosomes. First 22 pairs are somatic chromosomes. 23^rd pairs are sex chromosomes. That is caused by the absence of one set of genes from the short arm of one X chromosome. Usually they are females.   

Signs and symptoms – Growth rate is lower, Beast development is absence in normal age. Most of them are sexually inactive.

 Down’s syndrome

There have extra somatic chromosome in 21^st position of a person he or she has this syndrome. Down syndrome is usually affected by an error in cell division called nondisjunction.

                                              

Some infants with Down syndrome have only a few of these traits

·       Muscle hypotonia – low muscle tone

·       Flat facial profile – a somewhat depressed nasal

                                            bridge and have a small nose

·       Oblique palpebral fissures – an upward slant the eyes.

·       Dysplastic ear – an abnormal shape of the ear is differ from normal.

·       Single palmar crease – a single deep bent across the center of the palm.

                                           Thalassaemia

This is also a GTD. Actually this also a blood disorder. Cause the abnormal formation of hemoglobin. RBC carries Oxygen in body by the form of oxihemoglobin.  People have thalassemia have less amount of Hb. This also call as microcytic anemia. There have 2 kinds of thalassemia genes. Those are α and β. They are inherited autosomal recessive manner .5% of the world population have β thalassemia. It can only investigate by a blood test. Only can be treated by inject them blood. 

How it is transfer?

 

                                

Kasun Proboda Karawita