Consanguineous marriages in Brazil

This study tests whether seasonal differences in the United States and European sunshine is associated with human birth patterns. Birth data are adjusted for 31-day months, leap years, and an annual percentage. Clear observations and birth indices are correlated for European and U.S. cities. With 2-month exposure to clearness, r-values are Chicago (0.63), Bismarck (0.81), Dallas (0.86), Thessaloniki (0.66), and Copenhagen (0.54) and, with 3-month exposure, Amsterdam (0.69). Peak clearness occurs during the autumn for the United States and spring/summer for Europe. Differences in clearness may explain birth pattern differences and reduced U.S. births in the 1930s. Although the effect of vitamin D is plausible, further research is required.     

Consanguineous marriages in Afghanistan

The present cross-sectional study was done in order to illustrate the prevalence and types of consanguineous marriages among Afghanistan populations. Data on types of marriages were collected using a simple questionnaire. The total number of couples in the study was 7140 from the following provinces: Badakhshan, Baghlan, Balkh, Bamyan, Kabul, Kunduz, Samangan and Takhar. Consanguineous marriages were classified by the degree of relationship between couples: double first cousins, first cousins, first cousins once removed, second cousins and beyond second cousins. The coefficient of inbreeding (F) was calculated for each couple and the mean coefficient of inbreeding (α) estimated for each population. The proportion of consanguineous marriages in the country was 46.2%, ranging from 38.2% in Kabul province to 51.2% in Bamyan province. The equivalent mean inbreeding coefficient (α) was 0.0277, and ranged from 0.0221 to 0.0293 in these two regions. There were significant differences between provinces for frequencies of different types of marriages (p<0.001). First cousin marriages (27.8%) were the most common type of consanguineous marriages, followed by double first cousin (6.9%), second cousin (5.8%), beyond second cousin (3.9%) and first cousin once removed (1.8%). There were significant differences between ethnic groups for the types of marriages (χ2=177.6, df=25, p<0.001). Tajiks (Soni) and Turkmens (also Pashtuns) showed the lowest (α=0.0250) and highest (α=0.0297) mean inbreeding coefficients, respectively, among the ethnic groups in Afghanistan. The study shows that Afghanistan's populations, like other Islamic populations, have a high level of consanguinity.     

Consanguineous marriages in diocesis of Brno,Czechoslovakia

Summary The frequency of consanguineous marriages in our country which has been evaluated with regard to the corresponding time period does not differ on the whole from the data given for the European populations. The relatively higher frequency of consanguineous marriages in the years before the World War II was due to the greater endogamy among the German inhabitans especially in the frontier areas. The continuous decrease of the frequency of consanguineous marriages reveals the trend of our population to the panmixia. As the decrease of consanguinity rate in time is significant we recommend to use the data from the corresponding time period in calculating the genetic parameters.

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Zusammenfassung Die Häufigkeit von Verwandteneben in unserem Lande, die in Abhängigkeit von der Zeit zusammengestellt wurde, unterscheidet sich nicht von der Häufigkeit bei anderen europäischen Bevölkerungen. Die etwas höhere Häufigkeit in den Jahren vor dem Zweiten Weltkrieg war auf eine höhere Endogamie in der deutschen Bevölkerung der Grenzgebiete zurückzuführen. Ein kontinuierlicher Abfall der Häufigkeit zeigt den Trend zur Panmixie in unserer Bevölkerung. Da dieser Abfall statistisch signifikant ist, empfehlen wir die Benutzung von Daten aus gleichen Zeitabschnitten für die Berechnung der genetischen Parameter.

     

Consanguineous marriages in Beirut: Time trends,spatial distribution

Abstract

Twenty‐five per cent of all marriages are consanguineous in a population‐based sample of couples from Beirut. Marriages between distant relatives decline with time, while first‐cousin marriages remain relatively stable. Among first‐cousin marriages, the proportions of father's brother's daughter marriages (37 per cent) and of patrilateral unions (48 per cent) are particularly low. A spatial representation demonstrates an uneven distribution of consanguineous marriages, and an association of high levels of endogamy with Muslim religion, low educational level, and low occupational status.     

Consanguineous marriages in the province of Antalya, Turkey

To assess the trends in the frequency and the medical effects of consanguinity in the south coast of Turkish population using local and national data in the last 11 years. This cross-sectional study was carried out in Manavgat province, which is a major tourism center on the Mediterranean coast of Turkey. The authors studied consanguineous marriages in rural and urban population in the Mediterranean coast, Manavgat province, Turkey, via a 1500 random survey sample of married couples. There has been a significant increase in the incidence of consanguineous marriages in rural areas (40.7%) since 1989 in the southern population of Turkey. The results showed that the most frequent type of marriage was between the first cousins. It is found that there is no statistically significant difference between the consanguineous and non-consanguineous marriages in the different age groups. The results were discussed on the basis of educational status, reasons for having consanguineous marriages and the general medical effects as well as with the relation of congenital malformations. The custom of consanguineous unions in the Mediterranean population of Turkey is still extremely high, and preventive measures should be done to decrease its frequency and associated complications.     

Consanguineous marriages in the population of Sheikhupura (Punjab), Pakistan

This study was based on 1007 couples from the Sheikhupura population. The proportions of various parental relationships were: 0.3784 1st cousins, 0.0318 1st cousins once removed, 0.0784 double 2nd cousins, 0.1033 bradari distant relations, 0.3416 bradari, and 0.0665 unrelated parents. Mean paternal ages in unrelated couples are significantly higher than in 1st cousins, double 2nd cousins, and bradari relations. The differences in paternal and maternal ages are significantly higher in unrelated relations as compared to 1st cousins and double 2nd cousins. Procounced effects of consanguinity on parental deaths and neonatal deaths were observed in 1st cousin marriages compared to other relationships. Juvenile and infant deaths show comparatively less effects of consanguinity in 1st cousin marriages. Mean coefficient of inbreeding calculated for this population was 0.0271. Lethal gene equivalents calculated were 1.5424. The added risk of affected children in 1st cousins over that of unrelated parents was 4.82%. The results suggest that the deleterious genes show their effects more in the prenatal than in the postnatal period.     

Incidence of Friedreich ataxia in Italy estimated from consanguineous marriages

The frequency of consanguineous marriages up to second-cousin degree has been carefully established in the past for each of the 95 Italian provinces using the Archive of about 500,000 dispensations given by the Catholic church for such marriages over a 55-year period. It has therefore been possible to compare the frequency of consanguineous marriages observed among 83 couples of parents of Friedreich patients with the frequency of consanguineous marriages of the same degree in the different Italian provinces during the same years. From these data, an estimate of the incidence of the disease has been obtained for the whole nation (between 1/22,000 and 1/25,000). In Southern Italy, where 16 out of the 18 consanguineous marriages among Friedreich parents are concentrated, the incidence of the disease is similar (between 1/25,000 and 1/28,000). This study indicates that the Archive of consanguinity existing in Italy allows a reliable comparison of the frequency of consanguineous marriages among parents of patients with that of the general population. The same method can therefore be applied to the study of incidence of other autosomal recessive disorders in Italy.     

Note on estimates of the inbreeding coefficient through study of pedigrees and isonymous marriages

Crow and Mange (1965) developed a method to estimate the inbreeding coefficient (F) through an ingenious surname analysis. Such formulations assume a regularity of transmission of surnames, monophyletism, and random occurrence of consanguineous marriages. Accordingly, the ratio of isonymous partners to F of the offspring is equal to 4. Nevertheless, genealogy analyses show that the consanguineous marriages do not necessarily occur regularly. Therefore the isonymy analysis gives a misestimation of the inbreeding coefficient, depending on the prevailing form of nonrandomness. We suggest a small correction to the formulation in situations when pedigree information is available. The weighted mean of the ratio of isonymous partners to F of the known consanguineous marriages is suggested as a way to improve the formulas. The technique was applied to a northeastern Brazilian sample, and the results agree well with those of bioassays and therefore provide an apparently more realistic estimate of the inbreeding coefficient by isonymy.     

Consanguinity marriages in Brazil

This short review deals with the following problems: 1. frequencies of consanguineous marriages in Brazil; 2. their effects on precocious mortality (from abortions up to and including infant-juvenile mortality) and abnormalities among the survivors; 3. genetic counseling for consanguineous marriages; 4. reduction of the prenatal and post-natal damage in consequence of the abolition of the consanguineous marriages in Brazil.     

Genetic counseling in consanguinous marriages

The authors report their own experience as regard to the genetic counseling for consanguineous marriages. They observe that outpatients still marry and procreate despite the medical advices.     

Consanguineous marriage in a newly developed country: the Qatari population

This study examines the frequency of consanguineous marriage and coefficient of inbreeding in the State of Qatar. The study was conducted in semi-urban areas of Doha between January and May 2004. A sample of 1515 married Qatari females aged 15 years and over participated. The degree of consanguinity between each female and her spouse, and degree of consanguinity between their parents were recorded. The rate of consanguinity in the present generation was high (54.0%) with a coefficient of inbreeding of 0.02706. The commonest type of consanguineous marriage was between first cousins (34.8%). Double first cousin marriages were common (3.1%) compared with other populations. The consanguinity rate in the State of Qatar has increased from 41.8% to 54.5% in one generation.