A novel heterozygous mutation of BCL11B gene causes neurodevelopmental disorder and middle type hypospadias in a Chinese boy with 5 years follow-up

As a crucial transcription factor, BCL11 transcription factor B gene (BCL11B) is expressed in the cell nucleus, and also widely expressed in the nervous and immune systems. Function of BCL11B varied, mutation of BCL11B gene may involve diverse diseases, such as immunodeficiency 49 (IMD49) and intellectual developmental disorder with speech delay, dysmorphic facies, and T-cell abnormalities (IDDSFTA). Here we reported a Chinese boy with significant neurodevelopmental delay, whose genetic exam revealed the BCL11B gene mutation. During the 5-year follow-up, no serious immune system defects and infections were found, but some autism spectrum disorders gradually emerged, and the patient was finally diagnosed with IDDSFTA caused by BCL11B mutation. This study is the first to report the phenotypic association between BCL11B gene mutation and moderate hypospadias. Although a previous study has documented the co-occurrence of this gene mutation with hypospadias, the hypospadias in that case was of the mild form. The moderate phenotype presented in this case significantly expands the clinical spectrum of BCL11B-associated disorders.