[Epidemiologic study of myasthenia in Uruguay]. / Estudio epidemiológico de la miastenia en el Uruguay

During the period 1960 to 1976 170 cases of myasthenia were analyzed in the Laboratorio de Afecciones Neuromusculares del Instituto de Neurologia de Montevideo. This is an epiderom the total), pregnancy, surgical treatment (Thymectomy, 6%), lethally (13%). It is concluded that myasthenia is an unfrequent disease, with female prevalence (58%); between 30 to 70 years, starting by oculomotor signs (74%) and of severe prognosis in 24% of cases.

Genetic differentiation among Sardinian villages.

The present study reports an analysis of genetic differentiation among 14 Sardinian villages located mainly in the center of the island. Chi-square tests show significant genetic heterogeneity among villages, and analyses by F- and R- statistics indicate an essentially random pattern of differentiation for all alleles. Using the kinship methods of Morton, a matrix, R, with elements rij describing the correlations between the gene frequencies of villages i and j is obtained. Use of Malécot's formula relating the rij to the geographic distances between villages shows a rapid decline of kinship with increasing distance but reveals essentially no relationship for distances over 40 km. Rotation of a two-dimensional reduction of the kinship matrix to maximum congruence with the geographic distances indicates that about 25% of the genetic distances can be accounted for by the geographic location of the villages. Isolation due in part to cultural factors, genetic drift, and special local or regional patterns of villages associations appear to be involved in the pattern of genetic variation.