A study of hypertension in twins

A study of the blood pressure of 86 pairs of like-sexed twins over age 40 selected at random was performed. Twelve per cent were found to have a diastolic blood pressure in excess of 94 mm. Hg. In 4 out of 5 identical twin sets both members were found to have hypertension of about equal magnitude. In the fifth set, the predetermined definition of diastolic hypertension was not met in one member of the pair, although the systolic blood pressure was clearly elevated. In two identical twin sets, where information concerning previous blood pressure could be obtained, the age of onset of the hypertension differed. Among the 49 dizygetic twin sets, diastolic hypertension was found in 15 per cent of the individuals. In 3 of 12 of these pairs, it was present in both members.Since the prevalence of hypertension after age 40 in the identical twin sample resembles that in the population at large, it is concluded that the ultimate development of this condition is heavily dependent on genetic influences.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/32777/1/0000150.pd

Inheritance of quantitative expression of erythrocyte glucose-6-phosphate dehydrogenase activity in the Negro—a twin study

Studies have been conducted on eight sets of monozygous and nine sets of dizygous female Negro twins, both members of whom were heterozygous for G-6-PD deficiency. Twins were studied both by assay of erythrocytic G-6-PD activity and by the methemoglobin elution test (MET). The MET is a procedure which identifies histochemically cells with appreciable G-6-PD activity and permits accurate determination of the percentage of such cells in heterozygotes. Monozygous twins showed significantly less “within-pair” variation than dizygous twins with both the MET and G-6-PD assay.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44115/1/10528_2004_Article_BF00487735.pd