The child finally succumbed to his disease at 12 years of age. Infact, this disease is also called as bubble boy disease based on a boy who stayed in a plastic-covered sterile environment to prevent infections. SCID is a potentially fatal condition and bone marrow transplant (BMT) or gene therapy should be considered in these patients. What is the treatment of severe combined immunodeficiency? In the case of SCID due to ADA deficiency, ADA levels can be checked in the amniotic fluid or chorionic villus cells and ADA deficiency can be ruled in or out. In the case of SCID affecting only boys, if the current fetus is a female, then she would not be affected. Then in the current pregnancy, chorionic villus sampling or amniocentesis can be done and checked whether the fetus has the same mutation or not. Prenatal diagnosis for SCID can be done provided the genetic mutation causing SCID is known in a previously affected child in the family. Is prenatal diagnosis possible for severe combined immunodeficiency? This helps to determine the chances of recurrence in other children and whether only boys will be affected or both boys and girls will be affected. Genetic tests are available to detect specific mutations causing SCID. Immunoglobulin levels are also low in SCID.Īre there genetic tests available to diagnose severe combined immunodeficiency?

The most definitive test is to examine the function of T-lymphocyte which is depressed in SCID. The number of B-cells and NK cells help to classify SCID as T- B- or T-B+ SCID. Diagnosis is confirmed by demonstrating low T-lymphocytes. How is the diagnosis of severe combined immunodeficiency made?ĭiagnosis of SCID is suspected by depicting low lymphocytes in the blood (usually lymphocytes are more than 4000/cumm but in SCID they are less than 1500/cumm). Chest X-Ray will also show the absence of a thymus. The doctor will notice that in spite of serious infections, the child has no glands enlarged and tonsils are also absent (Lymph nodes and tonsils are where the lymphocytes are stored). This is known as graft versus host disease. Some children may also have a rash due to a reaction caused by the mother's T cells in the baby's blood circulation leading to a reaction against the baby's organs. Patients commonly have serious bacterial, viral, and fungal infections and may succumb to one of the infections. Infections by unusual organisms such as pneumocystis jiroveci (PCP), chickenpox, cytomegalovirus (CMV) are commonly seen. Symptoms of SCID are recurrent serious infections starting right in infancy. What are the symptoms of severe combined immunodeficiency (SCID)? There are other SCID causing mutations that have not been identified. Ligase 4 deficiency - Patients have absent T & B cells.Artemis deficiency - Patients have absent T & B cells.

Patients have absent T & B cells but normal NK cells.

Recombinase activating genes 1 and 2 (RAG 1 and RAG 2) deficiency.

Deficiencies of CD3 chains: Three types are seen.

Deficiency of the Janus Kinase 3 (JAK 3) - Patients have no T & NK cells but normal B cells that do not function properly.

However, B cells do not function properly. Affected children have no T cells but have normal B cells and NK cells.

Deficiency of the Alpha Chain of the IL-7 receptor.

ADA deficiency is the second most common cause of SCID and children have low T cells, B cells, and NK cells.

Adenosine Deaminase (ADA) deficiency - This type of SCID occurs due to mutation in the gene that forms ADA.

It has very low T-lymphocytes and NK-lymphocytes but B-lymphocyte count is high though they do not function properly.

Deficiency of the common gamma chain of six different cytokine receptors - This is the commonest form of SCID and seen only in males.

There are currently 12 known types of SCID based on various genetic mutations. What is the cause of severe combined immunodeficiency? It can lead to extremely serious infections which can even be fatal. SCID is a rare primary immunodeficiency disorder in which there is a combined absence of T-lymphocyte and B-lymphocyte function. What is severe combined immunodeficiency (SCID)?

Scid was cured in a patient in 1990 via