[Clinical pathology and molecular genetics on familial amyloidotic polyneuropathy]

To report the clinical, pathologic and molecular genetic features of a Chinese family with familial amyloidotic polyneuropathy (FAP) in Beijing area.

The proband was a 52-year-old woman with 7 years history of vomitting and diarrhea and weakness as well as anaesthesia. In her family there were 5 patients with initial presentation in three consecutive generations ranging in age from 21 to 45 years. Sensory neuropathy and systemic autonomic symptoms appeared in all the 5 patients, with muscle weakness in 2 cases in the later stage of disease. Gastrointestinal involvement appeared in the early stage of disease in all patients. Sural nerve biopsy was performed on the proband. The nerve specimens were applied for routine histological and ultrastructural investigation as well as immuno-histochemical staining with monoclonal antibodies against transthyretin (TTR) protein, immunoglobulin kappa- and lambda-chains. DNA analysis was performed on the proband and her son for TTR gene and apolopoprotein A1.

Amyloid, identified as amorphous eosinophilic extracellular deposits on Congo red staining and recognized by its characteristic fibrillar ultrastructure with electron microscopy, was identified arround small vessel in the endoneurium. Axonal loss was recorded as severe (> 75%). Immunoglobulin kappa- and lambda-chains as well as TTR positive deposits were not demonstrated in the accumulated amyloid material. There was neither TTR nor apolopoprotein A1 coding gene mutation detected in the proband and her son.

The pathological findings demonstrated existence of a FAP. However, the immuno-pathological and genetic results could not classified the type of this FAP family. Further genetic studies are required to identify it.