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Hong et al. J Transl Genet Genom 2018;2:8 Journal of Translational
DOI: 10.20517/jtgg.2018.06 Genetics and Genomics

Case Report Open Access

Detection of leukocyte adhesion deficiency type
1 in an infant by high-throughput targeted exome

sequencing

Sha Hong, Li-Juan Xie, Qing-Nan Yang, Tian-Wen Zhu

Department of Neonatal Medicine, Xin-Hua Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, Shanghai 200092,
China.

Correspondence to: Dr. Tian-Wen Zhu, Department of Neonatal Medicine, Xin-Hua Hospital Affiliated to Shanghai Jiao Tong University
School of Medicine, Kongjiang Road 1665#, Shanghai 200092, China. E-mail: zhutianwen@hotmail.com
How to cite this article: Hong S, Xie LJ, Yang QN, Zhu TW. Detection of leukocyte adhesion deficiency type 1 in an infant by high-
throughput targeted exome sequencing. J Transl Genet Genom 2018;2:8. https://doi.org/10.20517/jtgg.2018.06

Received: 8 Apr 2018 First Decision: 19 May 2018 Revised: 12 Jun 2018 Accepted: 15 Jun 2018 Published: 28 Jun 2018
Science Editor: Sheng-Ying Qin Copy Editor: Jun-Yao Li Production Editor: Huan-Liang Wu

Abstract
Leukocyte adhesion deficiency type 1 (LAD-I) characterized by immune-deficiency and leukocytosis is rare in
infant patients. A 43-day-old boy with severe leukocytosis, recurrent infections, defective wound healing and
hepatosplenomegaly associated with an acquired cytomegalovirus infection. To establish the diagnosis definitively,
a high-throughput targeted exome sequencing was performed, which yielded the diagnosis of LAD-I. A homozygous
mutation in integrin subunit beta 2 (ITGB2), c.817G>A (p.G273R) was identified. Though LAD-I has been thoroughly-
studied, with more than 300 detailed cases and 96 mutations in ITGB2, establishing a definitive diagnosis of LAD-I
in infancy is challenging because of the lack of typical clinical presentations. Better understanding the molecular
characterization of this disease is necessary to increase awareness and identification of infants with LAD-I.

Keywords: Immunodeficiency, leukocyte adhesion deficiency type 1, leukocytosis, ITGB2 gene, high-throughput targeted
exome sequencing

INTRODUCTION
[1]
Leukocyte adhesion deficiency type 1 (LAD-I) (MIM 600065) with an occurrence of 1 in every 100,000 live
births is an autosomal recessive leukocyte recruitment deficiency. It is characterized by recurrent bacterial
infections, poor wound healing, and delayed umbilical cord separation. Mutations have been found in
[2]
integrin subunit beta 2 (ITGB2) gene that is located at 21q22.3 (NM_000211), which leads to the associated
heterogeneous clinical spectrum of this disorder.

© The Author(s) 2018. Open Access This article is licensed under a Creative Commons Attribution 4.0
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