Pallister–Hall syndrome (abbreviated PHS) is a disorder that affects the development of many parts of the body. It is named for Judith Hall and Philip Pallister. Presentation
Most people with this condition have extra fingers and/or toes (polydactyly), and the skin between some fingers or toes may be fused  (cutaneous syndactyly). An abnormal growth in the brain called a hypothalamic hamartoma is characteristic of this disorder. In many cases, these growths do not cause any medical problems; however, some hypothalamic hamartomas lead to seizures or hormone abnormalities that can be life-threatening in infancy. Other features of Pallister–Hall syndrome include a malformation of the airway called a bifid epiglottis, laryngeal cleft, an obstruction of the anal opening (imperforate anus), and kidney abnormalities. Although the signs and symptoms of this disorder vary from mild to severe, only a small percentage of affected people have serious complications. Seizures
As noted above, the hypothalamic hamartoma can cause seizures. The most common types of seizures that occur are known as gelastic epilepsy. The term gelastic originates from the Greek word "gelos which means "laughter". Seizures may begin at any age but usually before three or four years of age. The seizures usually start with laughter and the laughter is often described as being "hollow" or "empty" and not very pleasant. The laughter occurs suddenly, comes on for no obvious reason and is usually completely out of place.
In some cases, an affected person inherits a mutation in the GLI3 gene from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family. Diagnosis
Treatment
Notable Cases
George William Helon (Australian author and businessman) is a Pallister-Hall Syndrome (PHS) patient, mentor, counsellor and advocate. References
Pallister–Hall syndrome at NLM Genetics Home Reference

External links

GeneReviews/NCBI/NIH/UW entry on Pallister–Hall Syndrome
Genetics Home Reference