Clinical Laboratory, Kyushu University Hospital, Fukuoka, Japan.
A patient with congenital factor V deficiency combined with mental retardation and several congenital anomalies including cleft palate, dwarfism, microcephaly and right hydrocele testis is described. The levels of factor V activity and factor V antigen of plasma were significantly decreased. The platelet lysate obtained from him also showed a significantly low level of factor V activity. Palatoplasty and tooth extraction were successfully performed under transfusion therapy with fresh-frozen plasma.