Adenosine deaminase deficiency (ADA deficiency)  is a  metabolic disorder that causes immunodeficiency. It is caused by  mutations in the ADA gene. It accounts for about 10–15% of all cases of autosomal recessive forms of severe combined immunodeficiency (SCID) among non-inbred populations.ADA deficiency can present in infancy, childhood, adolescence, or adulthood. Age of onset and severity is related to some 29 known genotypes associated with the disorder. It occurs in fewer than one in 100,000 live births worldwide. Signs and symptoms
The main symptoms of ADA deficiency are pneumonia, chronic diarrhea, and widespread skin rashes. Affected children also grow much more slowly than healthy children and some have developmental delay. Most individuals with ADA deficiency are diagnosed with SCID in the first 6 months of life.An association with polyarteritis nodosa has been reported. Genetics
The enzyme adenosine deaminase is encoded by the ADA 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. Pathophysiology
ADA deficiency is due to a lack of the enzyme adenosine deaminase.
Psychiatists may instead use a definition from the DSM-IV, defining nocturnal enuresis as repeated urination into bed or clothes, occurring twice per week or more for at least three consecutive months in a child of at least 5 years of age and not due to either a drug side effect or a medical condition. Management
There are a number of management options for bedwetting. The following options apply when the bedwetting is not caused by a specifically identifiable medical condition such as a bladder abnormality or diabetes. Treatment is recommended when there is a specific medical condition such as bladder abnormalities, infection, or diabetes. It is also considered when bedwetting may harm the childs self-esteem or relationships with family/friends. Only a small percentage of bedwetting is caused by a specific medical condition, so most treatment is prompted by concern for the childs emotional welfare. Behavioral treatment of bedwetting overall tends to show increased self-esteem for children.Parents become concerned much earlier than doctors. A study in 1980 asked parents and physicians the age that children should stay dry at night. The average parent response was 2.75 years old, while the average physician response was 5.13 years old.Punishment is not effective and can interfere with treatment. Treatment approaches
Simple behavioral methods are recommended as initial treatment. Other treatment methods include the following:

Motivational therapy in nocturnal enuresis mainly involves parent and child education. Guilt should be allayed by providing facts. Fluids should be restricted 2 hours prior to bed.