Magyarországi ikerkutatások: éegy évtized eredményei [Hungarian twin studies: results of four decades]

Twin studies play a role in examining the contribution of genetic variations and environmental factors responsible for the determination of phenotypic variables and of genetic linkage between genotypes. Hungarian twin studies, supported by three twin registries (among them two twin-database), date back to 1970s. Studies mainly focused on various congenital abnormalities, the effect of contraceptive pills and folic acid on the frequency of twin pregnancies, as well as psychosexual and alcohol consumptional behaviors. Monogenic Mendelian inheritance of lactose (mal)absorption was demonstrated for the first time. Hungarian Twin Registry was founded in 2007, which contributed to the current understanding on the background of several disorders, e.g. metabolic syndrome and atherosclerosis. As part of an international twin study, among others, arterial stiffness, central blood pressure, carotid intima/media thickness, venous biomechanics, body composition, lung function and smoking characteristics were also assessed. Absence of genetic background in non-alcoholic fatty liver disease and high inheritance of carotid plaque characteristics were demonstrated for the first time. The review also aims to summarize future plans of the Hungarian Twin Registry. Orv. Hetil., 2013, 154, 1579-1586

Environmental trichlorfon and cluster of congenital abnormalities

Of 15 live births in one Hungarian village in 1989-90, 11 (73%) were affected by congenital abnormalities and 6 were twins. Of the 11, 4 had Down syndrome. Likely causes of such clusters (known teratogenic factors, familial inheritance, consanguinity) were excluded. A case-control study and environmental investigations pointed the finger of suspicion at the excessive use of trichlorfon at local fish farms. The content of this chemical was very high in fish (100 mg/kg) and several pregnant women, including all mothers of babies with Down syndrome, had consumed contaminated fish in the critical period for the congenital abnormalities observed

The pattern of down syndrome among children in Qatar: A population-based study

BACKGROUND:,The objective of the present study was to determine the prevalence pattern of Down Syndrome (DS) in children < 5 years of age in the State of Qatar. This is a retrospective descriptive study. The study was conducted in the Hamad General Hospital, Women's Hospital, and Rumailah Hospital (Hamad Medical Corporation). A total of 146 children were reported as having DS during the 6-year period from I January 2000 to December 31, 2005. METHODS: The diagnostic classification of definitive DS was made in accordance with criteria based on the International Classification of Disease 10th Revision (ICD-10). The data collected from the medical records included sociodemographic characteristics of the children, genetic and family history, pedigree analysis, and clinical genetic examination. RESULTS: A total of 146 children were diagnosed with DS during the last 6-year period and the prevalence rate is 19.5 per 10,000 live births. Of these, 40.4% were Qataris and 59.6% were non-Qataris. DS was slightly more common in boys (52.7%) than girls (47.3%). Infants < 1 year old had the high. est frequency of DS (40.4%), followed by children (1-2) years (26%). The most common abnormality was regular trisomy (98%). Also, one-half of the studied children had congenital heart problems (51.7%), There is a significant relationship between DS and maternal age as reported by other studies in other countries. CONCLUSION: The identification of specific types of chromosomal abnormalities in DS children is important as it enables clinicians to accurately counsel the parent regarding the recurrence risk and available options