Pallister-Hall syndrome is a very rare genetic disorder characterized by polydactyly, nail dysplasia, a bifid epiglottis, and hypothalamic hamartomas producing specific forms of epilepsy. First signs are seen at birth. The prognosis depends on the severity of the disease, ranging from mild to severe and life-threatening. The diagnosis rests on a thorough clinical assessment, followed by imaging studies and molecular genetic testing.
Pallister-Hall syndrome, firstly described 40 years ago, is an extremely rare genetic disorder    . The pathogenesis stems from mutations in the GLI3 gene on chromosome 7p13, which is involved in the sonic hedgehog pathway, a key signaling process of cell maturation   . So far, the majority of cases have been described as familial with an autosomal dominant pattern of inheritance  . The nature of the disorder causes signs and symptoms to be evident from birth. Several key features comprise Pallister-Hall syndrome      :
Additional signs and symptoms include renal malformation (hypoplasia, agenesis, ectopic kidneys, or development of cysts), genitourinary changes (imperforate anus, hydrometrocolpos), and skeletal changes such as short limbs   .
Because of the very rare occurrence of Pallister-Hall syndrome in general practice, the diagnosis may be difficult to attain. For this reason, an early clinical workup is critical in order to recognize the key elements of this disorder. Physicians should first obtain a detailed patient history that will cover the onset of symptoms and their progression. A detailed family history must not be overlooked because of the autosomal dominant pattern of inheritance. After history taking, the physical examination can discover polydactyly and additional anatomical changes, but in order to solidify the diagnosis and obtain additional evidence toward Pallister-Hall syndrome, imaging studies are necessary. The cardinal feature, hypothalamic hamartoma, is best seen through magnetic resonance imaging (MRI), as neither computed tomography (CT) nor cranial ultrasonography are able to detect it . A non-calcified and non-enhancing mass, usually located behind the optic chiasm and on the third ventricle floor, exhibits an isointense signal on T1 and T2-weighted studies  . Molecular genetic techniques, which are able to detect the mutated GLI3 gene on chromosome 7, serve as the definitive method for diagnosing Pallister-Hall syndrome .