Endocrine Abstracts

JOINT1684

Objective: To report the long-term follow-up of a patient with Hallermann-Streiff syndrome (HSS) and growth hormone (GH) deficiency treated with GH therapy from early childhood to adolescence.

Methods: Case report and longitudinal evolution.

Results: A female patient diagnosed with HSS at 22 months was referred due to extreme growth failure (height –6. 6 SD). She was the second child of healthy, non-consanguineous parents. Family history was unremarkable. Pregnancy was uncomplicated, and delivery occurred at term (38 weeks), with a normal birth weight (2800 g) and length (48 cm). She had typical HSS features, bilateral congenital cataract surgery, and frequent respiratory infections. Intellectual development was normal. Endocrine evaluation showed persistently low IGF-1 (< 25 ng/mL), GH deficiency confirmed by stimulation tests (peak GH: 1. 52 ng/mL after glucagon, 6. 7 ng/mL after clonidine), and delayed bone age. GH therapy (0. 028 mg/kg/day) was started in 2012 and discontinued in 2024 (age 15 years, 7 months) due to epiphyseal closure. Growth response was modest (final height: 134. 4 cm, –4. 26 SD), likely affected by the syndrome, early infections, and skeletal factors. However, GH therapy improved IGF-1 levels, muscle tone, strength, and functional capacity, enhancing energy levels and endurance. No significant adverse effects were observed despite early recurrent infections. Menarche occurred at 13 years, 4 months, with regular and prolonged cycles. At last assessment (15 years, 8 months), weight was 35 kg (–2. 2 SD), BMI 19. 38 kg/m² (–0. 64 SD), with complete pubertal development. Bone mineral density (L1–L4: 734 mg/cm², Z-score –2. 7) was low for age and sex, likely due to poor dietary calcium intake. She is under multidisciplinary follow-up:

• Pulmonology: Allergic asthma, obstructive sleep apnea requiring BiPAP since age 6. No significant respiratory symptoms with activity.

• Nephrology: Hypertension treated with enalapril and amlodipine, difficult control.

• Cardiology: Moderate mitral regurgitation, no restrictions.

• Ophthalmology: Bilateral aphakia, nystagmus.

• Rehabilitation: No scoliosis. Uses a small heel lift.

Highly intelligent and academically driven, she previously played soccer but now prioritizes studies.

Conclusion: GH therapy had a limited effect on final height but significantly improved muscle tone, strength, and overall physical performance. This is the first reported long-term case of GH therapy in HSS reaching adulthood, highlighting the importance of individualized expectations in syndromic growth disorders and the role of GH beyond height improvement. A multidisciplinary approach is essential for optimizing long-term outcomes in HSS patients, particularly regarding bone health, cardiovascular function, and respiratory support.