NKX2.1-Related Disorders: a novel mutation with mild clinical presentation.

Background: A highly variable phenotype characterized by thyroid, respiratory and neurological defects has been reported in an already established group of disorders namely NKX2.1-related disorders. We describe here the case of an infant with a novel mutation of the NKX2.1 gene characterized by mild clinical presentation. Aim of the study was to elucidate the genotype-phenotype correlation in our patient. Methods: We performed genetic analysis of the NKX2.1 gene in an infant with no neonatal respiratory distress and near-normal results at neonatal screening test for congenital hypothyroidism, choreoathetosis, ataxia and delayed independent walking. Results: A novel mutation of the NKX2.1 gene has been identified, that is responsible for a mild framework of congenital hypothyroidism and neurological symptoms. Conclusions: The frequency of congenital hypothyroidism cases associated with NKX2.1 mutations is expected to be higher in a subgroup of patients, selected according to the neurological presentation. In these patients the analysis of NKX2.1 mutational status is recommended.