Biomedical subjects
C A Huether
Publications and source records attributed to C A Huether.
Integrating genetics into the medical school curriculum.
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Education section to continue!
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Human genetics education in medical schools--forward ho!
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Report of the Task Force on Teaching Human Genetics in North American Medical Schools.
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Nontraditional pedagogy for implementing human genetics education.
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Prenatal diagnosis in metropolitan Atlanta and the impact on autosomal trisomies.
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Temporal changes in Ohio amniocentesis utilization during the first twelve years (1972-1983), and frequency of chromosome abnormalities observed.
The history of amniocentesis utilization in the seventh largest state of the United States is documented from its inception in 1972 through the first half of 1984. Amniocentesis utilization ratios for Ohio residents aged greater than or equal to 35 have increased from 0.21 per cent (19/9091) in 1972 to 23.4 per cent (1655/7531) in 1983, representing an average annual growth rate of 43.1 per cent. Of the amniocenteses performed from January 1, 1978-July 1, 1984, 71 per cent were referred for advanced maternal age (greater than or equal to 35), 15 per cent for maternal anxiety (30-34), 10 per cent for family history or previous child with a genetic defect, and 4 per cent for other reasons. Between 1978-1983 utilization by women 45 years of age was only 20 per cent higher than women 35 even though their risk of giving birth to a Down syndrome child was bout one order of magnitude higher. In addition, various factors were tested as to whether they affected utilization of amniocentesis by women greater than or equal to 35 during 1978-1983. A strong correlation of +0.89 existed between county population size and utilization ratios. No difference in utilization was found between whites and nonwhites, regardless of county population size. When utilization ratios were compared separately between Protestants, Catholics and other religions in Ohio's most populated county, no statistical differences were found. From 1978-July 1, 1984, the frequency of all cytogenetically abnormal chromosome results observed in Ohio amniocenteses to women greater than or equal to 35 was 2.48 per cent (187/7536). Of these, 2.15 per cent (162/7536) had unbalanced karyotypes. Future maximum amniocentesis utilization for women greater than or equal to 35 is estimated at 60-70 per cent.
Revised estimates and projections of Down syndrome births in the United States, and the effects of prenatal diagnosis utilization, 1970-2002.
The objectives of this study were to: calculate revised estimates and projections of United States annual Down syndrome (DS) births for 1970-2002, and estimate the effects of amniocentesis on these baseline DS birth projections. Three models of amniocentesis utilization among 30-34 and greater than or equal to 35-year-old women were considered. The recently revised Census Bureau birth projections, and new single year maternal age DS risk rates estimated from a 1970-1983 Ohio data set, were used. Data from all three Census Bureau projection series were analysed; series II was considered in depth since it is consistent with recent fertility levels. Assuming no use of amniocentesis, total estimated DS births dropped from about 4770 in 1970 to 4120 in 1980 (a 14 per cent decline), but are projected to a plateau of about 5100 by the year 1990 (a 24 per cent increase). DS births to women greater than or equal to 35 would increase dramatically from about 1050 in 1980 to 1900 in 2000 (an 81 per cent increase). Assuming 1983 Ohio prenatal diagnosis ratios for women aged 30-34 (1.7 per cent) and greater than or equal to 35 (23.4 per cent) are used nationally, an annual reduction of about 7 per cent of DS births in 1986 and 9 per cent in 2002 would result. Fifty and 70 per cent utilization among women 30-34 and greater than or equal to 35, respectively, would reduce DS births by about 33 per cent in 1986 and 38 per cent in 2002. Therefore, if the projected increase in DS births is to be averted, utilization of prenatal diagnosis by greater than or equal to 30-year-old women must increase substantially.
Translocation Down syndrome in Ohio 1970-1981: epidemiologic and cytogenetic factors and mutation rate estimates.
Sixteen hundred eighty-eight Down syndrome live births, including 65 (5.2%) translocations, were ascertained in Ohio between 1970 and 1981. Translocations of known origin were 24.4% maternal, 2.2% paternal, and 73.3% de novo. Translocation subtypes were 14/21 (45.7%), 15/21 (2.9%), 21/21 (40.0%), 21/22 (2.9%), and other (8.5%). Among 14/21 translocations, 33.3% were maternal in origin and 66.7% were de novo, while 100% of 21/21 translocations were de novo. No differences were found when the maternal- and paternal-age distributions of all translocations or various translocation subsets were compared with the live-birth control distributions. However, mean maternal and paternal ages of de novo translocations were significantly lower than that of the live-birth controls. Ohio data showed the average maternal age of de novo D/21 cases to be significantly lower than the control. Ages of both parents of de novo G/21 cases and paternal age of D/21 cases were not different from the control. De novo translocation mutation rate estimates were 0.8 X 10(-5) for 14/21, 1.2 X 10(-5) for 21/21, and 2.2 X 10(-5) overall. Ohio estimates (3.2 X 10(-5) for 1970-1972 and 1.4 X 10(-5) for 1973-1975) did not reflect the increase in mutation rate previously found in New York during 1973-1977.
False-positive reporting of Down syndrome on Ohio and New York birth certificates.
Although correction for underreporting of congenital malformations on birth certificates is included in most studies, inaccuracy of reporting has not been widely examined. Two separate investigations were conducted on the inaccuracy of Down syndrome (DS) reporting on birth certificates; ie, false-positive cases in which an individual coded as DS did not in fact have DS. In Ohio, 824 individuals were coded as DS on their birth certificate during 1970-1981. Of these, a definitive determination as to whether or not they had DS was made on 778 by using cytogenetic data, medical records, the state's birth defects registry, school records, and by questioning physicians. Fifty-seven false-positives were found, indicating a 7.8% level of coding inaccuracy for all races and 6.9% for whites only. Nine of these arose from miscodings during data processing; 48 were misdiagnosed as DS. This can be contrasted with false-negatives also studied in Ohio, where 66.1% of DS cases were not reported on the birth certificate. No statistical differences were observed between false-positives and true DS in the distribution of sexes, in population size of county of birth, or in year of birth (although there was a declining false-positive rate over the 12 year period). The percentage of DS false-positives, however, was significantly higher for younger maternal ages (greater than or equal to 30 years) than older ones (greater than or equal to 30 years) and for nonwhites compared to whites. Further, there was a strong negative correlation between the percentage of false-positives and the degree of certainty expressed in reporting DS on the birth certificate.
Familial spastic paraplegia-clinical and pathologic studies in a large kindred.
Clinical studies of members of a six-generation kindred of familial spastic paraplegia support the diagnostic distinction of a pure form of this autosomal dominant disease. Onset was in the fourth decade or later and symptoms were those of progressive gait difficulties with lower limb spasticity and weakness. Sensor, cerebellar and cranial nerve changes were absent. Pathologic changes in one member were confined to the lateral corticospinal tracts and in the fasciculus gracilis.
A clinical study of vasectomy failure and recanalization.
An analysis was made of the 26 unsuccessful operations from the 2,197 vasectomies performed in a non-profit medical facility. Hhe operations were performed by 6 physicians and significant differences were found in the failure rates. In all instances the tissue removed proved to be vas deferens when examined histologically. Two factors seem to account for the differences of failure rates amoung the physicians; 1) the lenght of vas excised and 2) the character of thechnique. Phsicians with a high rate of success removed a significantly longer section of vas than physicians exhibiting higher failure rates. At least 15 mm. of vas should be excised to maximize the success of the procedure. Excised vas segments less than 15 mm. had up to a 25-fold greater incidence of failure. Although considered of secondary importance, good surgical technique subjectively measured by the minimal amount of accessory tissue attached to the excised vasa was also considered to aid in reducing the number of vasectomy failures.
Population education in U.S. schools: a status report.
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