[MIM 102 700]

(ADA deficiency, SCID due to deficiency in adenosine deaminase)

SCID is the acronym in English of  Severe Combined Immune Deficiency

Rare: 1/200,000 to 1/106 live births. Probable cause of 15 % of severe combined immune deficiencies, which are, by definition, a combined lack of functional  lymphocytes T and B. Autosomal recessive transmission of a mutation of the ADA gene in 20q13.11 that causes an accumulation of intracellular toxic metabolites (deoxyadenosine and deoxyguanidine) inducing the early apoptosis of the affected cells, particularly T-lymphocytes .

Clinical presentation of varying severity:

-        early form : severe and recurrent opportunistic infections since the neonatal period: lymphopenia, growth retardation, early death

-        sometimes delayed form (0-15%) beginning 1) after 6 months, or 2) in adulthood with a progressive decrease in immune function

-        non-immune events: neurosensorial deafness, liver  (hepatosplenomegaly) or skeletal abnormalities, behavioural disorders

-        a partial deficiency can cause no clinical manifestation

Treatment:

-        ideal: bone marrow or stem cell transplantation

-        effective: twice weekly IM or subcutaneous injection of pegylated adenosine deaminase  (PEG - ADA)

-        future: gene therapy by infusion of hematopoietic CD34 + transduced cells

Anesthetic implications: 

antibioprophylaxis and strict measures of asepsis; side effects of immunosuppressive drugs in case of hematopoietic transplantation

References : 

-        Tartibi HM, Hershfield MS, Bahna SL. 
A 24-year enzyme replacement therapy in an adenosine-deaminase-deficient patient. 
Pediatrics 2016; 137: e20152169

Updated: March 2019