A Novel De Novo Mutation of the TITF1/NKX2-1 Gene Causing Ataxia, Benign Hereditary Chorea, Hypothyroidism and a Pituitary Mass in a UK Family and Review of the Literature
A 23-year-old man was diagnosed with pulmonary alveolar proteinosis at the age of 11 months, and primary hypothyroidism gradually developed during infancy. He had delayed developmental milestones and severe hypotonia that evolved into non-progressive chorea during childhood. He died from large cell lung carcinoma at the age of 23 years. A de novo heterozygous insertion mutation 859–860insC in the TITF-1 gene was demonstrated. Conclusion: TITF-1 gene mutations should be considered in paediatric and adult patients with unexplained (combinations of) chorea, mental retardation, primary hypothyroidism, and chronic lung disease. Introduction of a name for the disorder, e.g. Brain-Thyroid-Lung syndrome, would probably facilitate further recognition. Whether the TITF-1 gene mutation in this patient predisposed to the development of lung cancer remains speculative.