Severe skeletal dysplasia caused by undiagnosed hypothyroidism.

Due to increased awareness of early clinical signs and introduction of neonatal screening for congenital hypothyroidism, long-term untreated hypothyroidism has become rare. Nevertheless, neonatal screening for congenital hypothyroidism is not performed in all countries, and not every affected patient might be picked up by neonatal screening alone. Here we describe a case of congenital hypothyroidism due to an ectopic thyroid that was not diagnosed for 13 years and resulted in severe skeletal changes beside mental disablement. The patient showed coarse facial features (hypertelorism, broad flat nasal bridge, broad face) and a severe truncal shortening due to kyphoscoliosis of the spine. X-rays detected highly retarded bone age, a widely opened anterior fontanelle, immature, flat bodies of the vertebra with ventral beaked deformities mainly in the lumbar region and no ossification centres in the head of the femurs. In this patient we found no evidence for a mutation of the PAX8 gene known to cause an ectopic and/or hypoplastic thyroid.