IRF6 mutation screening in non-syndromic orofacial clefting: analysis of 1521 families.

Van der Woude syndrome (VWS) is an autosomal dominant malformation syndrome characterized by orofacial clefting (OFC) and lower lip pits. The clinical presentation of VWS is variable and can present as an isolated OFC, making it difficult to distinguish VWS cases from individuals with non-syndromic OFCs. About 70% of causal VWS mutations occur in IRF6, a gene that is also associated with non-syndromic OFCs. Screening for IRF6 mutations in apparently non-syndromic cases has been performed in several modestly sized cohorts with mixed results. In this study, we screened 1521 trios with presumed non-syndromic OFCs to determine the frequency of causal IRF6 mutations. We identified seven likely causal IRF6 mutations, although a posteriori review identified two misdiagnosed VWS families based on the presence of lip pits. We found no evidence for association between rare IRF6 polymorphisms and non-syndromic OFCs. We combined our results with other similar studies (totaling 2472 families) and conclude that causal IRF6 mutations are found in 0.24-0.44% of apparently non-syndromic OFC families. We suggest that clinical mutation screening for IRF6 be considered for certain family patterns such as families with mixed types of OFCs and/or autosomal dominant transmission.

Antiepileptic drug use, folic acid supplementation, and congenital abnormalities: a population-based case-control study.

OBJECTIVE: To investigate whether folic acid supplementation in early pregnancy modifies the association between the prevalence of congenital abnormalities in the offspring and maternal use of carbamazepine (CBZ), phenobarbital (PB), phenytoin (PHT), and primidone (PRI). DESIGN: A population-based case-control study. SETTING: The Hungarian Case-Control Surveillance of Congenital Abnormalities (HCCSCA) (1980-1996) and its information on children from the Hungarian Congenital Abnormality Registry and the Hungarian National Birth Registry. POPULATION: Children with congenital abnormalities (cases; n= 20 792, of whom 148 had been exposed to antiepileptic drugs [AEDs]) and unaffected children (controls; n= 38 151, of whom 184 had been exposed to AEDs). METHODS: Information on drug exposure and background variables for the mothers were collected from antenatal logbooks, discharge summaries, and structured questionnaires completed by the mothers at the time of HCCSCA registration. MAIN OUTCOME MEASURES: Congenital abnormalities detected at termination of pregnancy, at birth or until 3 months of age according to CBZ, PB, PHT, or PRI exposure at 5-12 weeks from first day of the last menstrual period (LMP), stratified by folic acid supplementation. RESULTS: Compared with children unexposed to AEDs and folic acid, the odds ratio of congenital abnormalities was 1.47 (95% CI 1.13-1.90) in children exposed to AEDs without folic acid supplementation and 1.27 (95% CI 0.85-1.89) for children exposed to AEDs with folic acid supplementation. CONCLUSION: The results indicate that the risk of congenital abnormalities in children exposed in utero to CBZ, PB, PHT, and PRI is reduced but not eliminated by folic acid supplementation at 5-12 weeks from LMP. The statistical precision in our study is limited due to rarity of the exposures, and further studies are needed.

Maternal employment status and isolated orofacial clefts in Hungary.

AIMS: To study the role of maternal employment status as indicator of socioeconomic status in the origin of isolated orofacial clefts (OFC) and in the use of periconceptional folic acid/multivitamin supplementation. METHODS: 1,975 cases with OFC (1,374 cases with cleft lip +/- palate and 601 cases with posterior cleft palate), 38,151 population controls without any defects and 20,868 patient controls with other isolated defects were compared in the population-based data set of the Hungarian Case-Control Surveillance of Congenital Abnormalities (HCCSCA), 1980-1996. RESULTS: The proportion of professionals and managerials was lower, while the proportion of unskilled workers, housewives and others was higher in the mothers of cases with OFC compared with the population control group. However, the comparison of OFC and patient control groups did not show any difference in the employment status of mothers. A lower level of folic acid supplementation occurred in the professional and skilled worker mothers of cases with OFC compared with the population control group. This difference was confirmed by the comparison of folic acid used by mothers of cases with OFC compared with patient controls. An infrequent multivitamin use was displayed in the studied groups. CONCLUSIONS: The prevalence of OFC at birth shows a slightly lower maternal employment status as indicator of socioeconomic status than in the population control group. The higher level of maternal education does not imply a higher rate of folic acid supplementation in the group of OFC.

MtDNA and Y chromosome polymorphisms in Hungary: inferences from the palaeolithic, neolithic and Uralic influences on the modern Hungarian gene pool.

Magyars imposed their language on Hungarians but seem not to have affected their genetic structure. To better investigate this point, we analysed some mtDNA and Y chromosome polymorphisms in a sample of the Hungarian Palóc who, for historical reasons, could have retained genetic traces of Magyars more than other groups. In addition, we examined a mixed sample from Budapest. About 100 individuals were tested for the markers defining all the European and Asian mtDNA haplogroups and about 50 individuals for some Y chromosome markers, namely the 12f2 and 49a,f/TaqI RFLPs, the YAP insertion, the microsatellites YCAIIa, YCAIIb, DYS19 and the Asian 50f2/C deletion. In the mtDNA analysis only two subjects belonged to the Asian B and M haplogroups. The Y chromosome analyses showed that the Palóc differed from the Budapest sample by the absence of YAP+ allele and by the DYS19 allele distribution; that the proto-European 49a,f Ht 15 and the neolithic 12f2-8Kb were rather uncommon in both groups; that there is a high prevalence of the 49a,f Ht 11 and the YCAII a5-b1; and that the Asian 50f2/C deletion is absent. These results suggest that the influence of Magyars on the Hungarian gene pool has been very low through both females and males and the Hungarian language could be an example of cultural dominance. Alternative explanations are discussed. An expansion centred on YAP-, 49a,f Ht 11 is revealed by the median network based on compound haplotypes. 49a,f Ht 11 could represent either a paleolithic marker of eastern Europe which underwent expansion after the last glacial period, or a marker of the more recent spread of the Yamnaia culture from southern Ukraine.

Frequency of the R3500Q mutation of the apolipoprotein B-100 gene in a sample screened clinically for familial hypercholesterolemia in Hungary.

Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) cause early onset of coronary heart diseases (CHD). According to the recommendations of the international MEDPED program, we tried to find FH cases. We analyzed 73 FH probands and their 304 first-degree relatives. A total of 39 probands were found from the 21000 subjects screened (1:538) from family doctors' registers recording all citizens, while the remaining 34 were derived from screened patients from lipid clinics. In our FH probands, four cases of FDB (R3500Q mutation) were diagnosed with allele-specific PCR, and the mutation was also detectable in five cases out of seven living family members. In the remaining 69 FH families, 156 people were diagnosed clinically with FH, and 31.8% of the males (against 13% of the not clinically diagnosed FH males, P<0.01), and 32.4% of the females (against 13.5% of the not clinically diagnosed FH females, P<0.01) suffered from early onset CHD. The plasma total cholesterol level of the FDB patients, especially in the younger patients, was very close to normal values. Therefore, the FDB patients seem to be under-represented in this type of survey. Because FDB is one of the independent causes of early onset CHD, the R3500Q mutation should be considered in families with a high frequency of cardiovascular diseases.

Cholesterol screening in the members of the Hungarian parliament.

The high proportion (49%) of male parliament members with high cholesterol levels (> or = 240 mg/dl) calls attention to their high risk for cardiovascular diseases. Our hope is that knowledge of their risk will improve their understanding concerning the importance of lifestyle and health promotion in Hungary.

Euphenic prevention of coronary artery disease.

The purpose of this feasibility study was to incorporate the primary prevention of coronary artery disease (CAD) into periconception care. The first task was the preconceptional screening for CAD. The family and case histories and risk status of prospective mothers and fathers were obtained. Serum total cholesterol was measured in 3,530 female and 3,127 male participants. The mean serum nonfasting cholesterol was 192 +/- 40 mg/dl in women and 204 +/- 49 mg/dl in men. The levels of total cholesterol exceeded the upper limit of desirable total cholesterol (200 mg/dl) in 37% of women and in 49% of men. Only 7% of women and 5% of men had previous knowledge about their high total cholesterol. The second task was risk assessment for CAD in prospective parents and their planned baby and the identification of couples at high risk. The third step was the education of couples at high risk: how to reduce risk factors and how to enhance protective factors. Three months later, the short-term follow-up study indicated a 49 mg/dl (18%) and 43 mg/dl (16%) (range 250 to 300) reduction in total cholesterol in female and male participants, respectively, mainly due to an education program including change in diet, cessation of smoking, and so forth. The long-term follow-up will include both parents and children 3 years after the birth. Periconception care is appropriate for both a general and selective approach to population screening for total cholesterol and for primary prevention of CAD.

Human germinal mutagenic effects in relation to intentional and accidental exposure to toxic agents.

This paper presents examples of epidemiological evaluation of exposure- and cluster-type mutations in human populations. The self-poisoning model did not show that offspring born from mothers after a semi-lethal self-poisoning had higher rates of prenatal selection (fetal death) or abnormalities due to germinal mutations; however, an intrauterine growth retardation was found. The surveillance function of the Hungarian Congenital Abnormality Registry has detected many cluster-type situations, one example of which is an extreme increase of Down's syndrome in a small Hungarian village in 1989 to 1990. Environmental investigations have pointed to the excessive use of trichlorfon at local fish farms as the cause.

Schisis-association.

The neural tube defects (anencephaly, encephalocele, spina bifida cystica), oral clefts (cleft lip +/- palate, posterior cleft palate), omphalocele, and diaphragmatic hernia associate with one another far more frequently than at the expected random combination rates. The combination of other abnormalities does not exceed the expected rate. Thus, two or more combinations of schisis-type abnormalities without other defects were treated as a provisional entity. The schisis-association is practically a lethal abnormality. It occurs more often in girls (sex ratio: 0.33), in twins (4.6%), in breech presentations (13.7%), in association with lower mean birth weight (1,931 gm), and in association with a shorter gestation period (36.4 weeks). Mothers of affected children have a significantly higher miscarriage rate; occurrence of schisis-type abnormalities was found in 3.7% of the sibs of index patients. However, except for one, the sib-occurrences of schisis abnormalities were isolated neural tube defects or oral clefts.

Additive congenital anomaly patterns.

A family study was conducted on 1,038 index patients with unidentified multiple congenital abnormality (MCA) patterns in the population-based material of the Hungarian Congenital Malformation Registry (HCMR). Congenital abnormalities (CAs) were detected in 5.1% of fathers and in 4.2% of mothers, respectively. Two fathers had an MCA pattern similar to that in their affected child. One component CA of multimalformed index children occurred in 55.1% of fathers and 52.3% of mothers. Thus, in more than half of affected parent-child pairs, there may be a causal connection between the observed anomalies. The combination of CAs of different parental origin in index patients is called "additive CA pattern." This group of patients may represent about 5% of unidentified MCA patterns and about 50% of affected parent-child pairs.

A family study of congenital inguinal hernia.

In fathers and mothers of 707 index patients with operated indirect congenital inguinal hernia (CIH) born in Budapest during the years 1962-1966 the frequency of CIH was two and five to six times higher, respectively, than in the general population. The rate of affected sibs was higher than that of parents but was greatly dependent on the sex of the index patient. Heritability estimates of CIH vary significantly in parents (0.35 +/- 0.12) and in sibs (0.78 +/- 0.14). In twins the heritability is 0.77. These data agree with the multifactorial threshold model involving dominance variance.

Reduction of urinary tract and cardiovascular defects by periconceptional multivitamin supplementation.

The objective in the Hungarian randomised double-blind controlled trial was to study the preventive effect of periconceptional multivitamin supplementation on neural tube-defects and other congenital abnormalities. There were 2,471 and 2,391 informative offspring (prenatally diagnosed and terminated malformed fetuses, stillborn fetuses, and liveborn infants) in the multivitamin and placebo-like trace element groups, respectively. A single tablet either of a multivitamin containing 0.8 mg of folic acid or trace element supplement was given daily for at least one month before conception and at least until the date of the second missed menstrual period. The total rate of major congenital abnormalities was 20.6/1,000 in the multivitamin and 40.6/1,000 in the trace element group. After the exclusion of six cases of neural-tube defects in the trace element group the difference was very highly significant [P = 0.0003; relative risk of 0.54 (95% CI 0.39, 0.76)]. Multivitamin supplementation appeared to result in a significant reduction in the rate of urinary tract abnormalities, mainly obstructive defects, and in the rate of sporadic cardiovascular malformations, mainly ventricular septal defects. This report is regarded as a hypothesis-generating study encouraging others to see if the result can be repeated.

A family study of congenital diaphragmatic defects.

The occurrence of specific and nonspecific congenital anomalies was determined in first degree relatives of index patients with congenital diaphragmatic defects who were born in Hungary between 1970 and 1979 and were ascertained through a population-based registry. The cases were grouped into Bochdalek types (N = 156), other types (N = 26), unclassified types (N = 55), and multiple congenital anomalies (MCA) cases including those with congenital diaphragmatic defects (N = 96). The sib occurrence in the Bochdalek type was 0.9% (taking into consideration also the unclassified cases or the total material, it was 0.5% or 0.4%, respectively). Specific familial clusters were not found in other types. Neural tube defects were detected in 1.8% of sibs in the total material and 2.4% in MCA cases.

Congenital abnormalities associated with limb deficiency defects: a population study based on cases from the Hungarian Congenital Malformation Registry (1975-1984).

Limb deficiency defects (LD) occurring among 1,575,904 births in Hungary during 1975-1984 were reviewed. The overall birth prevalence of LD was 1 in 1,816. This paper discusses the nature and distribution of the limb and other defects in the 275 (32%) children who had structural malformations in other systems. Two main forms of classification were used: morphologic and causal. Additional malformations were most commonly seen in infants with amelia, rudimentary limb (RL), radial/tibial (RT), intercalary or central axis (CA) LD and rarely in those with terminal transverse (TT) or ulnar/fibular (UF) defects. Upper limbs (81%) were involved significantly more often than lower limbs (42%) and there were more right-sided defects (83% vs. 71%) due to an excess of right arm involvement especially with radial ray and split hand anomalies. Single limb involvement was relatively common with amelia (88%), UF (82%), RT (50%), and TT (50%) defects. With other LD, multimelic involvement was more characteristic. This was usually symmetric with intercalary and RL defects but asymmetric with CA anomalies and digital deficiencies (DD). From a causal perspective, 17% of cases had genetic disorders, 52% had recognized associations, anomalies, sequences, environmental causes or patterns of unknown origin, and 31% had unknown patterns of malformations. The commonest entities were amnion disruption sequence (16% of cases) and VACTERL association (8%). Both of these disorders showed unusual temporal distribution. As anticipated, patterns of malformations differed with the type of LD. Amelia and digital amputations were often seen with body wall defects, atypical anencephaly or encephalocele, and cleft lip reflecting amnion disruption. Rudimentary limb was seen with anencephaly, omphalocele, renal agenesis, aberrant genitalia, and imperforate anus, reflecting defects of blastogenesis including the cloacal exstrophy and caudal regression sequences and Schisis association. Radial/tibial defects were associated with different patterns depending on whether the limb defects were unilateral or bilateral. Unilateral defects occurred with anomalies suggesting VACTERL association or the facio-auriculo-vertebral anomaly, while bilateral defects occurred more often in genetic or potentially genetic disorders including VACTERL with hydrocephalus. Central axis defects showed three main patterns of association: one reflecting the ectrodactyly-ectodermal dysplasia-clefting syndrome; one with tongue anomalies representing a variant of oro-mandibular-limb (Hanhart) anomaly, and the last with hydronephrosis indicating a group of "acro-renal" syndromes. Strong associations with other anomalies were not seen in the groups with TT, UF, or intercalary defects.

Patterns of acrorenal malformation associations.

Limb and urinary tract defects have frequently been reported to occur together as components of a single acrorenal field defect or in many multiple malformation syndromes. However, the concordance of such anomalies has rarely been studied on a population basis or the relationships between specific limb and renal defects defined. This paper documents the patterns of acrorenal associations seen in over 1,500,000 infants born in Hungary in 1975-1984. In all, 1 in 1,800 infants had a limb deficiency and 9% of these (75 cases) had a urinary tract anomaly. Urinary tract anomalies were most commonly seen with radial ray defects, micromelia and amelia. The commonest recognized patterns were VACTERL association and the cloacal exstrophy and caudal regression sequences. Chromosomal and single gene defects also occurred. Numerical taxonomic techniques delineated six main clusters of patients. Important groupings included micromelia with renal agenesis, split hand/foot with hydronephrosis, and radial ray anomalies with VACTERL defects. The radial ray groups differed in the nature of the VACTERL anomalies seen and with respect to laterality, symmetry, and non-VACTERL anomalies. There was a strong association of bilateral limb defects with bilateral renal anomalies and unilateral with unilateral. Ipsilateral defects tended to occur in typical VACTERL cases, while contralateral defects tended to occur with additional non VACTERL midline anomalies. Although renal and limb anomalies are associated, in almost all cases malformations in other systems are also present. The precise nature of the malformation patterns seen appear to reflect differences in the nature and magnitude of the underlying dysmorphogenetic processes as well as the timing of their effects.

Kallmann syndrome in three unrelated women and an association with femur-fibula-ulna dysostosis in one case.

We describe three unrelated women with hypogonadotropic hypogonadism and anosmia; that is, Kallmann syndrome. Absence of olfactory bulbs and tracts and different degrees of asymmetric dysplasia of olfactory sulci were demonstrated by MRI. Both the father of Case 1 and the maternal aunt of Case 3 had anosmia, thus autosomal dominant inheritance seems to be likely. Patient 2 had Kallmann syndrome and FFU (femurfibula-ulna) dysostosis as a sporadic occurrence in her family.

Study of isolated apparent amniogenic limb deficiency in Hungary, 1975-1984.

A population-based and validated data set of 206 cases with apparent amniogenic limb deficiency was ascertained in Hungary between 1975 and 1984. Such limb defects frequently (36%) associated with nonlimb abnormalities. In 134 cases with isolated defects typically more limbs are affected, upper and lower limbs, right and left sides, and both sexes are equally affected. Case-control analysis of such isolated cases indicates a lower socioeconomic status of parents, a higher parity, more frequent unwanted pregnancies, preterm birth, and a higher rate of threatened abortion. Familial occurrence was not found in 415 first-degree relatives.

Causal study of isolated ulnar-fibular deficiency in Hungary, 1975-1984.

A population-based and validated data set of 114 cases with isolated ulnar-fibular deficiency was evaluated in Hungary, 1975-1984. Ulnar-fibular type had the third most common birth prevalence (0.07 per 1000) among isolated congenital limb deficiency types. This type is relatively rarely associated with nonlimb defects, a single limb is affected in two-thirds of cases, nearly all other cases had femur-fibula-ulna (FFU) dysostosis. Upper and lower limbs, right and left sides, are equally affected, however, there is an obvious male excess (71%). Case-control analysis indicated a lower birth weight due to intrauterine growth retardation, higher birth order, lower socioeconomic status of parents, and a more frequent reported subfertility. The family study identified one familial cluster (one siboccurrence) among 331 first-degree relatives.

Autosomal recessive acrorenal syndrome.

We describe two sibs with tetraectrodactyly and oligomeganephronic renal hypoplasia. The parents were unaffected. This syndrome of apparently autosomal recessive origin appears to be the first Mendelian form of the acrorenal developmental field defect identified so far.

The second report of Knobloch syndrome.

Two sibs affected with Knobloch syndrome comprising severe visual handicap (high myopia and retinal detachment with other defects), atypical occipital cephalocele, and unusual plantar creases are described.