NKX2-1 and brain-lung-thyroid syndrome: TTF-1 haploinsufficiency secondary to deletions or mono-allelic mutations of the NKX2.1 gene has been recognized as a rare cause of neonatal or infantile respiratory failure, often associated with congenital hypothyroidism and/or benign hereditary chorea [16-20], referred to as "brain-lung-thyroid syndrome".