Endocrine Abstracts

JOINT3702

We report the case of a 3-year-old boy referred for short stature and growth failure, with a history of familial lymphohistiocytosis (FHL), for which he underwent allogenic hematopoietic stem cell transplantation (HSCT) at 3 months of age. The child was born at term with a birth weight of 4.010 kg and length of 51 cm. At 5 weeks, he was hospitalized for fever, leading to the diagnosis of FHL, confirmed by genetic analysis revealing a pathogenic variant in the PRF1 gene. Initial treatment with corticosteroids, cyclosporine, and alemtuzumab failed to induce remission, resulting in an HSCT. Following successful transplantation, growth was impaired. Family history revealed a target height of 176.5 cm (-0.58 SD), with both parents of Pakistani origin and first cousins, but no history of short stature or endocrine disorders. At the time of the HSCT, the height was 59 cm (-1.17 SD) and the weight was 6kg800 (0.7 SD). Clinical examination at 3 years 9 months revealed a height of 85.6 cm (-4.12 SD), weight of 14.8 kg (-0.86 SD), and a BMI of 20.2 kg/m² (+2.91 SD). He exhibited relative macrocephaly, rhizomelic shortening, but no other dysmorphic features. Growth velocity was measured at 4.3 cm/year. The differential diagnosis included growth hormone deficiency, skeletal dysplasia, and glucocorticoid-induced growth suppression. Hormonal evaluation showed IGF1 levels of 39 ng/ml, IGFBP3 at 1.8 mg/l, and normal thyroid function and cortisol levels. A normal glucagon test ruled out growth hormone deficiency. Radiographic imaging revealed dysplastic changes, including shortened humeral diaphyses, proximal epiphyseal dysplasia of the humerus, and iliac bone dysplasia. Despite a normal skeletal dysplasia panel, these findings were consistent with possible chondrodysplasia. At the follow-up visit at age 6 years 3 months, height was 96.5 cm (-4.52 SD), with a growth velocity of 3.3 cm/year. The diagnosis of probable chondrodysplasia and growth failure following early HSCT was made, based on the findings of Botto et al. (2020), who described a series of 7 children with similar growth failure and radiographic changes after HSCT for non-oncologic pediatric diseases, suggesting a new potential complication. This case highlights the importance of careful monitoring of growth and skeletal development in children undergoing HSCT for non-oncologic conditions, as they may be at risk for both endocrine and skeletal complications.