Laterality disturbance and hypopituitarism
A case report of co-existing situs inversus totalis and combined pituitary hormone deficiency. The authors present the case history of a 52-yr-old male patient with a unique association of combined pituitary hormone deficiency (CPHD) and situs inversus totalis. Except for signs and symptoms of pituitary hormone deficiency, the patient had no dysmorphic features, and hearing impairment, primary mental or neurological defects were also absent. Pituitary magnetic resonance imaging (MRI) scan showed hypoplasia of the anterior lobe of the pituitary gland and an ectopic posterior pituitary lobe. Despite the presence of situs inversus totalis, the patient was right-handed and functional MRI demonstrated left-hemisphere activation during language tests. Kartagener syndrome was considered, but immunofluorescence analysis showed normal localization of the outer dynein arm protein in respiratory epithelial cells obtained from the nasal mucosa. Direct DNA sequencing of all coding exons of the pituitary transcription factor 1 (PIT1) and prophet of PIT1 (PROP1) genes failed to detect disease-causing mutations, suggesting that these genes were not involved in the development of CPHD in our patient. More interestingly, the potential role of the paired like homeodomain transcription factor 2 (PITX2) gene, which has been implicated not only in CPHD, but also in left-right patterning in animal models, was also excluded, as sequencing showed the absence of mutations in coding exons of this gene. To our knowledge, PITX2 gene mutations have not been investigated in CPHD patients who had situs inversus totalis. We conclude that in contrast to animal models, the PITX2 gene is not involved in the development of situs inversus totalis, at least not in our CPHD patient.