Other specific studies included mucopolysaccharidosis type I [34], homocystinuria and methylation defects [42], primary immunodeficiencies [29], cystic fibrosis [38], congenital hypothyroidism [39], adenosine deaminase severe combined immunodeficiency [35], atypical hemolytic uremic syndrome [30], and inflammatory rheumatic diseases [46], with 1 study each. The gene discussed is ADA; the disease is cystic fibrosis.