Central Precocious Puberty in Williams Syndrome: Two Cases Illustrating Diagnostic Challenges and Individualized Management.

Central precocious puberty (CPP) is an increasingly recognized endocrine comorbidity in girls with Williams syndrome (WS), but its diagnosis and management may be complicated by the short stature and atypical growth pattern associated with WS. We report two girls with genetically confirmed WS and CPP who showed different clinical presentations and treatment courses. Both patients presented with advanced pubertal development and markedly advanced bone age. In Case 1, pubertal growth acceleration was not readily apparent on standard population-based growth charts but became evident when assessed using WS-specific growth charts. Gonadotropin-releasing hormone agonist (GnRHa) therapy initially achieved sustained pubertal suppression, but the improvement in predicted adult height (PAH) was limited. Recombinant human growth hormone (GH) was subsequently added, and PAH progressively increased. In Case 2, rapid progression from breast development to menstrual bleeding prompted early combined treatment with GnRHa and GH. During follow-up, bone-age advancement remained limited and PAH increased above the mid-parental height, allowing planned discontinuation of GnRHa and continuation of GH. These cases highlight the value of WS-specific growth charts for recognizing abnormal growth acceleration and support individualized treatment strategies guided by pubertal progression, bone age advancement, growth velocity, and serial PAH assessment.