would show the number of cases as is indicated in table 17.

The estimation of the total number of goiters in Chicago would seem to be 77,973 exophthalmic goiters and 63,092 simple goiters or a total of 141,065. This would show a ratio of 1 affected person in every 20 of an unselected group or 5.2 per cent of the population. The Chicago Bureau of Public Health estimated 200,000 affected persons or 7 per cent of the population of the city with goiters.

A comparison of the incidence of goiters in Chicago and St. Louis shows the number of cases to be 2 per cent greater in Chicago as based

on the Army Record. The hospital reports from Chicago and St. Louis show 3 per cent more of the illness in Chicago to be due to goiter than in St. Louis.

The observations of the estimated incidence according to the Army Report and the hospital records show that among the expected 52 goiters in 1000 people of Chicago about 8 were serious enough for hospital service. In St. Louis 5 cases of the expected 30 in 1000 people were serious enough for hospital service.

Similar estimations for St. Louis showed a ratio of 30 affected persons in 1000 or 3 per cent giving a total of about 23,000 cases of goiter in the population of St. Louis.

It is evident from these results that the proportional incidence of goiter in St. Louis is a little more than half as great as in Chicago. This degree of prevalency seems great enough to consider St. Louis as a goiter region. Further investigations of various localities along the Missouri River will be necessary before the cause in St. Louis can be considered to be the water from this river as was thought to be the case with the Sioux Indians in the Dakotas. Whatever the cause, it seems to be a variable factor as was evident by the decided variation in the death rate in the years 1919-1922.

SUMMARY

The estimated incidence of goiter in Chicago is 52 in 1000 and 30 in 1000 in St. Louis or near 150,000 goitrous people in Chicago and 24,000 affected in St. Louis. The total incidence is more than 6 times greater in Chicago than in St. Louis.

A comparison of the mortality records of St. Louis and Chicago showed that the proportion of deaths due to goiter to deaths from other causes was 6 times greater in St. Louis than in Chicago.

The sex ratio of the disease was found to be 1 affected man to 6 affected women in Chicago and 1:9 in St. Louis.

The race ratio as found among the cases reported in St. Louis was 1 affected colored patient to 9 white patients.

The greater number of cases of goiter seem to occur in people between the ages of twenty and thirty years of age. The most common type of goiter in Chicago was exophthalmic goiter and simple goiter was most frequent in St. Louis.

INTRODUCTION AND DISCUSSION OF

LITERATURE

Any discussion of the incidence of goiter in a region will eventually lead to the question of the causes of the disease. (At present the exact cause for the disease in the various regions is not known although references have been made to water and infection and many methods of treatment are advocated.) If there is a reason for believing that goiter is influenced by environment changes, there is also reason for thinking that the disease may be inherited.

Many physicians have noted the presence of several cases of goiter in one family and have considered the hereditary predisposition as the only evident cause for their presence. J. E. Summers (1915) summarizes his observations of many family histories, in which goiter was very prevalent, by stating that there are too many family histories showing a high incidence of the disease to disprove the inheritance of it. He believes some families have a predisposition for goiter the same as for tuberculosis and he considers congenital goiter to resemble congenital syphilis in being a germ infection which develops a goiter in the fetus in intra-uterine state.

Porter and Vonderlehr (1921) believe goiter to be due to pure heredity and endemic causes since goitrous mothers in non-goitrous regions do not bear children with goiter yet the child may have a predisposition to the growth in later life, that is, at puberty or during the child-bearing period.

Vallery-Radot (1922) found thyroid heredity principally transmitted through women and in the cases of

Basedow's disease they observed similar cases of heredity occurring in several generations and affecting several children in one family. They found myxedema in several members of a family but further heredity through these members was not noticeable since typical myxedematous individuals are generally sterile. Cases of simple goiter were known to have transmitted symptoms of Basedow's disease to the child.

Baillarger (1873) made a survey of France to determine the incidence in the various regions and in his report discusses the influence of heredity. He found children of goitrous parents had a predisposition to develop goiter although they were not subject to endemic influences. These cases will develop goiter if the hereditary influence is strong enough. This familial influence was also evident in the instance of goitrous persons who left an endemic region and yet their children born several years later were found to have goiters. These children, having the predisposition to develop goiter in an endemic region, did not show goiter symptoms at birth but developed a goiter during childhood. Baillarger has emphasized the importance of familial influence by reports of many families in which goiter was very prevalent and quite evidently caused by heredity.

These references suggest the importance of investigating the family histories of patients and so attention was given to the familial tendency in cases found in hospitals in Chicago and St. Louis in order to estimate the possible influence of heredity in these regions.

MATERIAL

One hundred family histories on goiter cases of patients from each city were investigated to determine the possible predisposition to the disease.

In reviewing the 500 unselected goiter histories from a Chicago hospital, 100 or 20 per cent of the cases showed one or more cases of goiter in the family. The observations made on these 100 selected histories were compared with a similar number from St. Louis.

FAMILY PREDISPOSITION TO GOITER SYMPTOMS

The total number of relatives of these patients from St. Louis was 2781 and the review of their family records showed 248 cases of goiter. Eight and nine-tenths per cent of the members of these families were affected, which indicates that in the population of people showing cases of goiter in the family there would be 89 persons with goiter in 1000. This compared to the results of the Army Report which showed 30 cases in 1000 is about 3 times the incidence expected from the population. This incidence suggests that the family predisposition to goiter would be influential in the increase in number of goitrous patients in St. Louis.

The family histories for the group of cases found in Chicago contain 640 individuals of whom 38 per cent were affected. This high incidence was partly due to the consideration of only three generations in each history. The family records from St. Louis included three or four generations in most cases. There was therefore a greater number of relatives

eight times more frequently than brothers giving evidence for a sex ratio of 1:8.

The number of affected men in the groups from Chicago and St. Louis showed twice as many from Chicago. The 17 cases of male patients in Chicago showed 2 fathers, 6 mothers, 14 sisters and 4 brothers with goiters. In one case the father, his two daughters and one son of four were affected. This was an unusual record and indicates half of the children to be goitrous. This being a case of inheritance, the paternal influence in transmitting the hereditary tendency was as affective as that of a goitrous mother.

INFLUENCE OF SUCCESSIVE
GENERATIONS

The number of affected and normal individuals in each of four generations was recorded from 100 case histories of patients in St. Louis. Table 19 indicates that there were almost four times as many goiters in the second generation as in the first. The third generation showed only 0.5 per cent less than the second but the fourth generation showed only slightly more than the first. It was evident that the familial influence on goiter did not affect the fourth generation to any great extent but that the second and third generations were equally affected. It seems to suggest that a diseased thyroid would have a pronounced two generation influence in most of the cases but a noticeable decrease in the fourth, as shown by family histories of patients in St. Louis.

A similar analysis of three generations of family histories of patients in Chicago showed nearly 4 times more

ANNALS OF CLINICAL MEDICINE, VOL. III, NO. 4

goitrous persons in the second generation than in the first which was also true of the cases reported in St. Louis. The results of the third generation were quite in contrast to the same among St. Louis patients. There were nearly 13 times more goitrous persons in the third generation than in the second of Chicago patients while among those in St. Louis the number of relatives affected in generation II and III were the same in proportion. This suggests increased hereditary influences towards a predisposition for the disease; the cases from Chicago showed a more typical instance of the increased influence by

The number of affected persons in these two groups of family histories showed 30.4 per cent of the persons in the families in Chicago were affected and 19.2 per cent of the persons in St. Louis family histories were affected.

There were no cretins reported which is quite in contrast to the records of cases in Europe in which goitrous mothers are reported to bear cretinous offspring or cretins are reported in the fourth generation (Summers, 1915). Gordon (1922) explains this in his report on cretins found in various regions of America. He found no case of endemic cretinism as is found