Analysis of lower birth weight in infants with congenital limb deficiency.

A case-control study on different groups of isolated congenital limb deficiency was performed using a population-based and validated Hungarian data set of 537 cases. All groups showed a significantly lower birth weight. The adjusted odds ratio indicated a significantly lower mean birth weight in infants with terminal transverse deficiencies and a significantly higher rate of preterm birth in those with amniogenic defects (part of the early amnion rupture sequence). The different analyses showed that the lower birth weight in the terminal transverse group was caused mainly by intrauterine growth retardation. Lack of limb parts appears to be of secondary importance, especially in the upper limb.

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.

[Split hand/foot abnormalities: classification, pathogenesis, epidemiology]. / Hasadt kéz/láb rendellenesség: osztályozás, kóreredet, epidemiológia.

Authors report on the genetic epidemiologic investigation of one of the sentinel anomalies made on purpose to define the birth prevalence of the different types of it, to calculate the mutation rate of autosomal dominant forms as well as to recognize the clinical features of Hungarian cases. 58% of all cases registered in the Hungarian Congenital Abnormality Registry in 1975-1984 proved to be atypical. The birth prevalence of autosomal dominant forms was 1.33/100.000 total birth. 71% of dominant forms was sporadic since 29% was familial. Thus the mutation rate was estimated 4.7 x 10(-6) +/- 1.22 x 10(-6).

The evaluation of the germinal mutagenic impact of Chernobyl radiological contamination in Hungary.

The genetic consequences of radioactive fall-out deposition from the Chernobyl (USSR) accident in Hungary was evaluated as a part of the ongoing programme on the population-based Hungarian Surveillance of Germinal Mutations. The surveillance is based on three groups of indicator conditions: 15 sentinel anomalies (indicators of germinal dominant gene mutations), Down's syndrome (an indicator of germinal numerical and structural chromosomal mutations) and unidentified multiple congenital abnormalities (indicators of germinal dominant gene and chromosomal mutations). Cases with these indicator conditions were selected from the material of the Hungarian Congenital Abnormality Registry. After the diagnostic accuracies were checked, familial and sporadic cases were separated. Only the latter group was evaluated for evidence of new mutations. The analysis did not reveal any measurable germinal mutagenic effects of the Chernobyl accident. Furthermore, there were no significant differences in the rates of these three groups of indicator conditions between regions with higher and lower increased background radiation.

[Holt-Oram syndrome]. / Holt-Oram-syndroma.

Authors report on the genetic epidemiologic investigation of the upper limb--cardiovascular (Holt-Oram) syndrome. The source of cases was the material of the Hungarian Congenital Malformation Registry. Birth prevalence was 0.95/100,000 total births. 85% of all cases proved to be consequences of new mutations, hence the mutation rate was 4.07 x 10(-6) +/- 3.12 x 10(-6).