A homozygous 5 base-pair deletion in exon 10 of the adenosine deaminase (ADA) gene in a child with severe combined immunodeficiency and very low levels of ADA mRNA and protein

• Published in: Human molecular genetics 1993-09, Vol.2 (9), p.1493-1494
• Main Authors: Gossage, David L., Norby-Slycord, Colette J., Hershfied, Michael S., Markert, M.Loulse
• Format: Article
• Language: English
• Subjects: adenosine deaminase; Adenosine Deaminase - deficiency; Adenosine Deaminase - genetics; Base Sequence; Biological and medical sciences; deletion; DNA, Complementary - genetics; genes; Homozygote; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; immunodeficiency; Immunopathology; Infant; levels; Male; man; Medical sciences; Molecular Sequence Data; mRNA; RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Deletion; Severe Combined Immunodeficiency - enzymology; Severe Combined Immunodeficiency - genetics
• ISSN: 0964-6906; 1460-2083
• DOI: 10.1093/hmg/2.9.1493

Adenosine deaminase (ADA) is an enzyme of the purine salvage pathway that catalyzes the deamination of adenosine to inosine and deoxyadenosine, respectively. In humans, absence of ADA activity causes severe T and B cell dysfunction resulting in severe combined immunodeficiency (SCID). Sixteen different mutations which result in SCID have been described at the ADA locus. Eleven are missense mutations; two are splicing defects. Among those which have been analyzed, all have near normal levels of ADA mMRNA. Two different gross chromosomal deletions have been reported; these are associated with absent or very low amounts of ADA mRNA. In a separate case a 2 base-pair deletion in exon 6 was identified. We report a 5 base-pair deletion in exon 10 of the ADA gene in a patient with very low levels of ADA mRNA and protein.