IgA nephropathy associated with X-linked thrombocytopenia.
X-Linked thrombocytopenia (XLT) is characterized by congenital thrombocytopenia with small platelets and absence of immunodeficiency; XLT is an allelic variant of Wiskott-Aldrich syndrome (WAS). Both entities are caused by mutations in the same gene. This study presents the case of an 8-year-old boy with XLT. He developed immunoglobulin A (IgA) nephropathy at the age of 4 years. Genetic analysis confirmed the XLT diagnosis. His maternal uncle also had thrombocytopenia from early infancy and developed end-stage renal failure as a result of IgA nephropathy. The maternal uncle was inferred to be affected with XLT because of the carrier status of the patient's mother. Abnormal glycosylation has a role in pathogenesis in IgA nephropathy; moreover, sialophorin glycosylation is defective in WAS. Altered glycosylation may contribute to renal involvement in patients with WAS/XLT despite different defective glycosylation patterns in IgA nephropathy and WAS/XLT.
Department of Pediatrics, Saiseikai Toyama Hospital, Toyama, Japan. stingray19659@hotmail.com
Hiro
H
Matsukura
Hirokazu
H
Kanegane
Kazushi
K
Miya
Keisuke
K
Ohtsubo
Akira
A
Higuchi
Takakuni
T
Tanizawa
Toshio
T
Miyawaki
D002648:Child; D040181:Genetic Diseases, X-Linked / Q000503:physiopathology*; D005922:Glomerulonephritis, IGA / Q000235:genetics*; D006031:Glycosylation; D006801:Humans; D008297:Male; D013921:Thrombocytopenia / Q000235:genetics*; D014923:Wiskott-Aldrich Syndrome / Q000503:physiopathology*