Rapidly Progressing Early Puberty in a Boy with Bilateral Basal Ganglia Germinoma and TREX1 Variant

Introduction: Organic lesions, including brain tumors, should be suspected in boys with precocious puberty. However, it is not usually suspected in children with early puberty. Case Presentation: Here we present an extremely rare case of rapidly progressing early puberty with basal ganglia germinoma coupled with three-prime repair exonuclease 1 (TREX1) variant. This was a 10-year-old-boy with borderline mental retardation and rapidly progressing puberty. Physical examination revealed 10 mL testes (Tanner stage 3 for genital development), and his bone age was that of a 12-year old boy. Laboratory findings showed abnormally elevated serum β-human chorionic gonadotropin (23.0 mIU/mL; reference, 0-10 mIU/mL), and suppressed LH level (<0.07 mIU/mL) with high testosterone (4.61 ng/mL; reference, 0.1-0.32 ng/mL). Magnetic resonance imaging revealed irregular enhancement in bilateral basal ganglia, and stereotactic biopsy confirmed germinoma. Whole exome sequencing was performed, and the pathogenic variant of TREX1 (TREX1:c.G832A) was revealed. Conclusions: This is the first case report of rapidly progressing early puberty caused by germinoma of bilateral basal ganglia associated with pathogenic variant of TREX1.