X-linked Thrombocytopenia with Normal Wiskott-Aldrich Syndrome Protein Expression in Lymphocytes and a Novel Wiskott-Aldrich Syndrome Protein Gene Variant: A Case Report and Brief Review of the Literature

Serena Hamanaka; Toru Uchiyama; Tadashi Kaname; Motohiro Matsui; Hiroshi Yoshihashi; Atsushi Makimoto; Yuki Yuza; Akira Ishiguro

doi:10.1016/j.jpedcp.2024.200128

X-linked Thrombocytopenia with Normal Wiskott-Aldrich Syndrome Protein Expression in Lymphocytes and a Novel Wiskott-Aldrich Syndrome Protein Gene Variant: A Case Report and Brief Review of the Literature

J Pediatr Clin Pract. 2024 Oct 10:14:200128. doi: 10.1016/j.jpedcp.2024.200128. eCollection 2024 Dec.

Authors

Serena Hamanaka¹, Toru Uchiyama², Tadashi Kaname³, Motohiro Matsui⁴, Hiroshi Yoshihashi⁵, Atsushi Makimoto⁴, Yuki Yuza⁴, Akira Ishiguro⁶

Affiliations

¹ Department of General Pediatrics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
² Department of Human Genetics, National Center for Child Health and Development, Tokyo, Japan.
³ Department of Genome Medicine, National Center for Child Health and Development, Tokyo, Japan.
⁴ Department of Hematology/Oncology, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
⁵ Department of Clinical Genetics, Tokyo Metropolitan Children's Medical Center, Tokyo, Japan.
⁶ Center for Postgraduate Education and Training, National Center for Child Health and Development, Tokyo, Japan.

Abstract

We present a case of X-linked thrombocytopenia (XLT) with a novel WAS gene variant expressing a normal amount of Wiskott-Aldrich syndrome protein (WASp) in lymphocytes. XLT usually decreases WASp expression not only in platelets, but also in lymphocytes. However, there were cases, such as the present one, in which WASp was expressed normally in lymphocytes and absent only in platelets. Our finding suggests that it is of greater diagnostic sensitivity to perform an expression analysis of WASp in both platelets and lymphocytes when XLT is suspected.

Keywords: Wiskott-Aldrich syndrome protein; X-linked thrombocytopenia; lymphocyte; novel variant.