Familial spastic paraplegia with distal muscle wasting in the Old Order Amish; atypical Troyer syndrome or "new" syndrome.

The Troyer syndrome was found by Cross & McKusick (1967) in 20 members of 12 Old Order Amish families in Holmes County, Ohio; it is a form of hereditary spastic paraplegia combined with distal muscle wasting, i.e. signs of involvement of lower motor neurons. The condition usually begins at 1 to 2 years and progresses at variable rates. Further manifestations include growth retardation, delayed speech development with dysarthria and drooling, and cerebellar signs; mental functions are usually not affected but severe emotional lability is a common finding. Brothers in a Wisconsin Old Order Amish family are reported with spastic diplegia, mental retardation, behavioral disorder and shortness of stature; the condition apparently is not progressive, and may be a "new" syndrome but could also represent a variant of the Troyer syndrome. Autosomal recessive inheritance is most likely, although consanguinity of the parents could not be proven. Another child in this family suffers from focal scleroderma (morphea) which is not related to the neurological syndrome.