[A case report of BCL11B mutation induced neurodevelopmental disorder and literature review].

To analyze the clinical , immunological and genetic features of a child with BCL11B mutation induced neurodevelopmental disorder. The clinical data and genetic test of a child with BCL11B mutation hospitalized in the Department of Rheumatology and Immunology in Children's Hospital of Chongqing Medical University in December 2018 were extracted and analyzed. The literature was searched with "BCL11B mutation" and "immunodeficiency 49" as key words in Chinese databases and Pubmed until January 2019 was reviewed. A male patient aged 3 years and 11 months with facial dysmorphisms and delayed language and motor development was admitted due to neurodevelopmental retardation over two years. Laboratory tests showed normal human immunoglobulin (IgG 12.90 g/L, IgA 1.02 g/L, IgM 1.15 g/L, IgE 532 000 U/L), Trec (228) and proliferation of T and B cells. The lymphocyte subsets revealeda reduced percentage of B cells (0.108) but normal absolute numbers (0.574×10(-3)/L), and an increased percentage (0.828) as well as absolute numbers (4.415×10(-3)/L) of T cells. A heterozygous BCL11B mutation was detected by sanger sequencing, showing a de novo frameshift mutation c.1887_c.1893delCGGCGGG in exon 4. Two papers were found which were all in English, with total of 14 patients(13 patients with complete information). Thirteen mutations were reposed, including 7 frameshift, 2 nonsense, 2 missense, and 2 chromosomal rearrangements; Thirteen patients had heterozygous mutations. All patients had delayed language and motor development and facial dysplasia which were mainly hypertelorism, thin eyebrows and small palpebral fissures. Some patients had dental anomalies, ametropia and allergy, and a few were combined with immune impairment, but without overt signs of immunodeficiency. Only one patient had multisystem anomalies and profound immune deficiency. BCL11B is essential for development of the nervous and the immune system. In this study, the de novo mutation of BCL11B gene resulted in neurodevelopmental and immunological disorders.