The codon 200 lysine mutation of the prion-protein gene is consistently present among Libyan Jews with Creutzfeldt-Jakob disease, strongly supporting a genetic pathogenesis of their illness. The similarity of the clinical courses of the patient homozygous for this mutation and the patients heterozygous for it argues that familial Creutzfeldt-Jakob disease is a true dominant disorder.

These data argue that the E200K mutation alone is sufficient to cause prion disease and does so in an age-dependent manner.

We identified 70 Creutzfeldt‐Jakob disease patients with the previously described E200K mutation in the prion protein gene. The purpose of this study was to define the clinical features of E200K homozygous patients (n = 5), compared with heterozygotes. We found a statistically significant younger age at disease onset for the homozygous patients, although the average age at onset in this group was still in midlife. Disease features were not statistically different in the two groups. Possible explanations are discussed. Ann Neurol 2000;47:257–260

The influence of pregnancy on multiple sclerosis was studied in 338 women by determining in each trimester of pregnancy and post partum the number of relapses and the corresponding relapse rate. Eighty-five relapses occurred in association with 1 9 pregnancies, most (65) in the postpartum period, and a low number of relapses ( 2 ) were recorded in the last trimester of pregnancy. Comparing the average exacerbation rate of the study group with that of patients with multiple sclerosis in Israel (0.28 relapses per person per year), we found a statistically significant decrease in the third trimester (0.04) and a high increase in the first three months postpartum (0.82). This pattern of remissions at the end of pregnancy and exacerbations post partum is similar to that observed in other putative autoimmune diseases. Our aim in the present study was not just to assess the general influence of pregnancy on MS, but to compare with other MS patients the number of relapses occurring in each trimester of pregnancy and post partum as well as the corresponding relapse rate. The study was undertaken because a number of putative autoimmune diseases show clinical remissions in the second half of pregnancy as well as exacerbations post partum {Sl. Materials and MethodsNationwide studies have been carried out in Israel since 1960 to identify and classify all cases of MS in that country. The National Neurological Disease Registry, maintained by the Uri Leibowitz Neuroepidemiology Unit of the Department of Neurology at Hadassah University Hospital in Jerusalem, was the source of patient records 1131.Criteria for the diagnosis of MS were those used by the Neuroepidemiology Unit, and are a modification of those published by McDonald and Halliday [15}, Bauer [2], and Rose and colleagues { 2 11. Patients were grouped in one of three diagnostic categories: clinically definite, probable, or possible MS. Our study included all clinically definite and probable cases since 1960. In each case we indicated the number and dates of pregnancies, year of onset of the disease, and number and dates of relapses occurring during pregnancy or post partum. A relapse was defined as the appearance of new symptoms in addition to confirmation of new signs or objective evidence of aggravation upon medical neurological examination. The first exacerbation was counted as the onset of the disease. We looked for the relapses occurring during pregnancy and related each relapse to the month of pregnancy during which it occurred. Nine months of pregnancy (divided into three terms) and 6 months of the postpartum course were reviewed. Patients in whom relapses occurred during pregnancy or post partum were followed for an additional 1.5 years after the end of the postpartum period. In those patients we counted the number of relapses occurring from the 15th to the 33rd month, considering the beginning of the pregnancy as the first month.In each period we calculated the relapse rate (number of relapses per person per year) using a x2 test. The denominator was the total ...