Raquitismo hipofosfatêmico ligado ao X: estudo de caso familiar e perspectivas da reabilitação

Abstract

X-Linked Hypophosphatemic Rickets (RHLX) is the most prevalent hereditary rickets form with a dominant inheritance pattern, attributed to mutations in the PHEX gene. These mutations lead to elevated levels of Fibroblast Growth Factor-23 (FGF-23) and subsequent phosphate loss. RHLX affects about 1 in 20,000 people. This condition causes persistent hypophosphatemia due to increased urinary phosphate excretion, resulting in skeletal deformities, short stature, and various medical symptoms. The current study aimed to conduct a genealogical analysis of a family with documented cases of RHLX and to discuss the prospects for rehabilitation, especially physical therapy interventions. Data collection involved interviews and clinical records, leading to the construction of a pedigree illustrating family relationships and affected individuals. Interviews with two family members yielded a five-generation pedigree, revealing two affected individuals: a woman in generation IV and her son (the proband) in generation V. The clinical report for the child, issued in 2023 by the medical team at Hospital Sarah Kubitschek in Belo Horizonte, Minas Gerais, indicated progressive bowing of lower limbs, short stature, and laboratory findings consistent with RHLX. Given that this condition follows an X- linked dominant inheritance pattern, the pathogenic mutation in the PHEX gene was transmitted from mother to proband, suggesting a 50% risk for affected women to have affected offspring, regardless of sex. Recent international guidelines recommend multidisciplinary follow-ups for these patients, where physical therapy can play a crucial role in treatment and improve rehabilitation quality of life. However, we noted the absence of specific therapeutic guidelines and/or programs in Brazil and a lack of controlled, randomized clinical studies to validate their efficacy.