Anomalous development of 3rd and 4th branchial pouches leading to thymic hypoplasia is the mechanism of defect for

The anomalous development of 3rd and 4th branchial pouches which leads to thymic hypoplasia particularly the 22q11.2 deletion is the mechanism of defect for Di-George Syndrome or DGS.

This is a primary immunodeficiency disease caused due to abnormal migration and development of tissues and certain cells during the course of foetus development.

There are certain functional deficiencies such as decrease in number of the T-cells, normal or decreased serum Ig, and normal B-cells.

The Di-George syndrome has a micro deletion of the chromosome 22q11.2 also known as the DGS critical region is also referred to as 22q11.2 deletion syndrome.

The symptoms of Di-George syndrome include developmental delay, congenital heart problems, cleft palate and frequent infections.

The Di-George syndrome is caused by deletion of 30 or 40 genes in the middle of chromosome 22, the particular location known as 22q11.2. Every person has 2 copies of chromosome 22, one inherited from each parent. If a person has Di-George syndrome, one copy of the chromosome 22 is missing a segment which includes around 30 to 40 genes.

The deletion of the genes from the chromosome 22 is a random event of father’s sperm or the mother’s egg.

The effects of this syndrome vary widely and have its effect on several parts of the body. Infections are common in this syndrome due to the problems arising in the immune system’s mediated response as in some patients the hypo plastic thymus is absent.

Children diagnosed with Di-George syndrome have a particular profile of neuropsychological test.

Patients who have Di-George syndrome can develop some autoimmune disorders at a higher rate than the general population. The exact mechanism which causes this syndrome and the features associated with it are still not known completely.

The diagnosis of the Di-George syndrome is done basis the symptoms at the time of birth or which develop soon after birth and get confirmed through genetic testing. Exact treatment and cure for Di-George syndrome is still not known but certain individual features are treated using the available standard treatments.

DiGeorge Syndrome is a mechanism defect where in an anomalous development of the third and 4th branchial pouches leading to thymic hypoplasia. Its functional deficiencies include: a decrease in T cells, normal B cells and normal or decreased serum Immunoglobulin.

Approximately 90% of patients with DGS have a minute deletion in chromosome number 22 at 22q11.2 position. Patients with DiGeorge syndrome may have any or all of the following: unusual facial appearance, heart defects, thymus gland abnormalities, autoimmunity, parathyroid gland abnormalities and other clinical features.

answer; ///i believe that the correct answer is (a) specialized cells)

answer: decrease

a limiting factor is the one which decrease the abundance, distribution and causes extinction of the population of species in a ecosystem. here, predators including hawks, owls and snakes are the limiting factor for the population of mexican free tailed bat.   although bats are nocturnal animals as they forge for food at night these predators also may remain active during night which can decrease the population of the mexican free-tailed bats. also, these bats eat only one type of insects that are moths. the food can also be a limiting factor as all 400 members are dependent upon same type of food needs that are moths. the decrease in the moth population can cause decrease in population size of the mexican free-tailed bats.

therefore, the scenarios will most likely to decrease the population size of the mexican free-tailed bats.