Specialty hematology ICD-9-CM 279.2 DiseasesDB 260 | ICD-10 D81.3 OMIM 102700 | |
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GeneReviews Adenosine Deaminase Deficiency | ||
Adenosine deaminase deficiency (also called ADA deficiency or ADA-SCID) is an autosomal recessive metabolic disorder that causes immunodeficiency. It occurs in fewer than one in 100,000 live births worldwide.
Contents
It accounts for about 15% of all cases of severe combined immunodeficiency (SCID).
ADA deficiency may be present in infancy, childhood, adolescence, or adulthood. Age of onset and severity is related to some 29 known genotypes associated with the disorder.
Pathophysiology
ADA deficiency is due to a lack of the enzyme adenosine deaminase. This deficiency results in an accumulation of deoxyadenosine, which, in turn, leads to:
Because T cells undergo proliferation and development in the thymus, affected individuals typically have a small, underdeveloped thymus. As a result, the immune system is severely compromised or completely lacking.
Genetics
The enzyme adenosine deaminase is encoded by a gene on chromosome 20. ADA deficiency is inherited in an autosomal recessive manner. This means the defective gene responsible for the disorder is located on an autosome (chromosome 20 is an autosome), and two copies of the defective gene (one inherited from each parent) are required in order to be born with the disorder. The parents of an individual with an autosomal recessive disorder both carry one copy of the defective gene, but usually do not experience any signs or symptoms of the disorder.
Age of onset and severity is related to some 29 known genotypes associated with the disorder.
Treatment
Treatments include:
On September 1990, the first gene therapy to combat this disease was performed by Dr. William French Anderson on a four-year-old girl, Ashanti DeSilva, at the National Institutes of Health, Bethesda, Maryland, U.S.A.
In April 2016 the Committee for Medicinal Products for Human Use of the European Medicines Agency endorsed and recommended for approval a stem cell gene therapy called Strimvelis, for children with ADA-SCID for whom no matching bone marrow donor is available.