Short stature and hypothyroidism in a child with Nail-Patella Syndrome. A case report

Background: Nail-Patella syndrome (NPS) (OMIM: 161200) or hereditary onycho-osteodysplasia is an autosomal dominant disorder characterized by skeletal anomalies, nail dysplasia, renal and ocular abnormalities. The diagnosis is based on clinical and radiological findings and confirmed by the identification of a heterozygous pathogenic variant in the LMX1B gene. Management of these patients involves continuous follow-up and treatment of the orthopedical, ocular and renal problems that may occur. Objective: To describe a case of NPS with short stature and hypothyroidism, an association that has not been described in the literature. Case report: An eleven-year-old boy with a height of 130 cm (-2.01 Standard Deviations [SD]) was referred to the Endocrine Unit at the age of 2 years due to altered thyroid tests. At that time, dysplastic nails and disproportionate short stature were detected. Radiological abnormalities initially suggested a skeletal dysplasia. A primary hypothyroidism was confirmed, without anti-thyroid antibodies and with a normal thyroid ultrasound. Levothyroxine treatment was initiated. The diagnosis of NPS was confirmed by a genetic study with a single pathogenic variant in the LMX1B gene. His father presented a similar phenotype with normal stature. His bone age was equivalent to his chronological age. Laboratory screening for short stature and a GH stimulation test were normal. Conclusion: We present a child with proven NPS with short stature and hypothyroidism. We did not find publications that described this triple association. It can't be ruled out that there could be a relationship between NPS and the thyroid alterations found in this patient.