ESPE Abstracts

A 2.6-year-old girl of Egyptian origins comes to our attention due to a deflection of the growth rate. The girl was born small for gestational age (SGA), and is affected by congenital hypothyroidism, with normal sized thyroid, treated with Levothyroxine. At the age of 1.8, due to right lameness, an x-ray of pelvis and lower limbs was performed, as indicated by the orthopaedic. The examination showed absence of the distal tibial ossification nucleus in the right leg and entanglement of the trabecular design of the distal metaphyseal region; therefore, she underwent magnetic resonance imaging of the ankles, showing distal meta-epiphyseal dysmorphism in the right tibia, with dysmorphic and irregularly ossified epiphyseal nucleus. Moreover, the articular cartilage of the tibial epiphyseal nucleus presented with central chondral centimetric defect. These findings were seen to a lesser extent contra-laterally. Her clinical examination revealed brachydactyly with short phalanges, saddle nose, round face, asymmetry in the lower limbs (the left leg was longer than the right one), attitude in flexion of the right elbow. Blood tests showed PTH 121 pg/ml (normal range: 15-65), calcium 9.16 mg/dl (normal range: 9-11), phosphorus 5.55 mg/dl (normal range: 3.8-6.3), alkaline phosphatase in normal range, 25-hydroxy-vitaminD 33.9 ng/ml (lower limit of normal >20), screening for celiac disease resulted negative. TSH 23.1 microUI/ml (normal range: 0.36-3.74) with Ft4 1.44 ng/dl (normal range: 0.76-1.46), and negative antibodies therefore we adjusted the L-thyroxine posology. The x-ray of the left hand-wrist confirmed the presence of brachydactyly with short and dysmorphic phalanges. The tests and the clinical presentation of the girl were found compatible with congenital dysostosis or pseudohypoparathyroidism. Thus, genetic analysis (NGS) for genes related to pseudohypoparathyroidism and bone dysplasia was performed; this examination revealed a heterozygous variant of the PRKAR1A gene, classified as pathogenic and associated with acrodysostosis, a rare disease, related to pseudohypoparathyroidism. Acrodysostosis is characterized by adult short stature, brachydactyly and facial dysostosis, it is associated with multiple hormonal resistances, always to PTH and TSH. These patients are often born SGA and have different degree of cognitive impairment. Diagnosis is based on clinical presentation, blood tests and genetic analysis (mutations of the PRKAR1A and PDE4D genes). Since this is a rare and heterogenous condition, the management of these patients must be based on a multidisciplinary approach. However, more evidence is needed to better understand long term clinical outcomes and treatment options.