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

 Organic lesions, including brain tumors, should be suspected in boys with precocious puberty. However, it is not usually suspected in children with early puberty.

 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.

 This is the first case report of rapidly progressing early puberty caused by germinoma of bilateral basal ganglia associated with pathogenic variant of TREX1.