Maternal germinal mosaicism of X-linked agammaglobulinemia.
X-linked agammaglobulinemia (XLA) is an immunodeficiency caused by abnormalities in tyrosine kinase (BTK), and is characterized by a deficiency of peripheral blood B cells. We studied cytoplasmic expression of BTK protein and analyzed the BTK gene (BTK) in peripheral blood mononuclear cells from two siblings with XLA and additional family members. Cytoplasmic expression of BTK protein in monocytes was not detected in either patient with XLA. A single base deletion (C563) in BTK-exon 6, which encodes the TH domain, was identified in both XLA patients. However, normal cytoplasmic expression of BTK protein in monocytes was detected in their mother without any BTK mutation. These results strongly suggest germinal mosaicism in the mother.
Second Department of Pediatrics, Toho University School of Medicine, Tokyo, Japan.
M
M
Sakamoto
H
H
Kanegane
H
H
Fujii
S
S
Tsukada
T
T
Miyawaki
N
N
Shinomiya
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000361:Agammaglobulinemia / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D003593:Cytoplasm / Q000201:enzymology; D004252:DNA Mutational Analysis; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008297:Male; D009030:Mosaicism; D009035:Mothers; D009154:Mutation; D010375:Pedigree; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D014960:X Chromosome
D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human