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Hypophosphatasia is characterized by defective bone mineralization associated with impaired activity of the tissue non-specific alkaline phosphatase (TNSALP) due to mutations in the TNSALP gene. We describe a child with a mutation that has not been described up to now. Case report. - A 4-year-old child presented with clinical symptoms of rickets and premature loss of decideous teeth. Reduced serum alkaline phosphatase activity and radiographic features led to the diagnosis of hypophosphatasia, which was confirmed by genetic investigation. The molecular study showed two missense mutations, of which one is a novel mutation. Conclusion. - Hypophosphatasia is suspected in a child with rickets and premature loss of decideous teeth. Such symptoms should prompt the search of a reduced serum alkaline phosphatase activity. The clinical and molecular diagnosis of the disease is important for the genetic counseling but also for a proper determination of prognosis, as it is related to the type of mutation. (C) 2004 Elsevier SAS. Tous droits reserves.

Certain familial breast and/or ovarian cancers, specially those diagnosed early, are dominantly heritable and have been linked to mutations in BRCA1 and BRCA2 genes. We have tested 30 women selected from 25 different families with specific criteria. Blood samples were always taken with the informed consent and preliminary interview of the patient by a physicologist specialized in presymptomatic testing. Mutation detection were performed by protein truncation test (PTT), gradient gel electrophoresis (DGGE) and subsequent sequencing. The results showed four frameshift mutations among which three induced truncation of the BRCA1 protein and one of the BRCA2 protein. One of the BRCA1 mutations and the only BRCA2 mutation are prevelant among caucasians. Interestingly, one BRCA1 mutation is shared both by Dutch and French families and another one has not yet been reported. Furthermore, a new unclassified varient was identified. Conclusion: by using specific selection criteria, we have been able to detect BRCA mutations in four out of the 25 families tested. One of the mutations seems to be found only in Belgium. Genetic counselling is being offered to their relatives. (C) 1998 Rapid Science Ltd.

We wish to report two cases of congenital abnormality after antenatal car accidents resulting in ruptured spleen and severe hypotension in the mothers at 8 and 14 weeks gestation. The first case had the classical Moebius syndrome with 6th and 7th cranial nerve palsy with abnormal brain stem evoked responses, presumably due to hypoxic/ischaemic brain stem damage and the second case had severe retardation and hypertonic cerebral palsy which at post mortem was found to be due to old hypoxic/ischaemic lesions to the caudate nucleus putamen and striatum.The cases described provide evidence that severe maternal hypotension during pregnancy can be associated with lesions to the midbrain and brain stem of offspring. The mechanism is probably utero-placental insufficiency, and extrapolation from these two unusual cases would support utero-placental insufficiency as a cause of Moebius syndrome and limb deficiency after chorionic villus sampling.

Cleft lip with or without cleft palate (CL/P) is one of the most common birth defects in the world. Prevalence varies between populations, with an average of 1/700. CL/P has a major clinical impact, requiring surgical, dental, orthodontic, speech, hearing and psychological management throughout childhood. The aetiology of CL/P is mostly unknown, and it is thought that both genetic and environmental factors play a role. Several causative genes for inherited syndromic forms of CL/P have been identified, and some recent studies have shown that these genes also contribute to the occurrence of isolated forms. Van der Woude syndrome (VWS) is one of the best models for non-syndromic CLP. It is an autosomal dominant disorder characterised by the presence of pits on the lower lip in addition to CL/P. Pits are the only feature distinguishing VWS from isolated clefts. Interestingly, in numerous VWS patients, the lip pits are very small and not readily diagnosed, thus mimicking isolated CL/P. Mutations in the IRF6 gene were shown to be the major genetic cause of VWS.'We performed direct sequence analysis of IRF6 on samples from a large European cohort and identified mutations in 27 (80%) families. This shows that IRF6 is the major causative gene of VWS in Europe also. Moreover, it is the gene to study when a seemingly isolated CL/P patient has minor signs, such as lip pits, since the identification of a mutation in IRF6 is associated with an increase in the risk of having a child with CL/P from 4-6%, the risk of transmission of an isolated cleft, to 50%, the risk of transmission of a dominant Mendelian disorder like VWS. Moreover, we studied the association of isolated CL/P with the IRF6 locus using two variants in a set of 195 patients from Belgium. As in an American study, a clear association was observed. This suggests that IRF6 also contributes to the occurrence of sporadic, isolated CL/P, even if no mutation in the gene can be identified in such patients.In conclusion, genes that are mutated in familial syndromic forms of CL/P may be predisposing genetic factors to sporadic isolated CL/P. Due to technological advances and the availability of the human genome sequence, we have now the opportunity to try and unravel the genetic factors behind the various forms of CL/P.

Background: Most cases of Sotos syndrome are caused by intragenic NSD1 mutations or 5q35 microdeletions. It is uncertain whether allelic or genetic heterogeneity underlies the residual cases and it has been proposed that other mechanisms, such as 11p15 defects, might be responsible for Sotos cases without NSD1 mutations or 5q35 microdeletions. Objective: To develop a multiplex ligation dependent probe amplification (MLPA) assay to screen NSD1 for exonic deletions/duplications. Methods: Analysis was undertaken of 18 classic Sotos syndrome cases in which NSD1 mutations and 5q35 microdeletions were excluded. Long range polymerase chain reaction (PCR) was used to characterise the mechanism of generation of the partial NSD1 deletions. Results: Eight unique partial NSD1 deletions were identified: exons 1–2 (n = 4), exons 3–5, exons 9–13, exons 19–21, and exon 22. Using long range PCR six of the deletions were confirmed and the precise breakpoints in five cases characterised. This showed that three had arisen through Alu - Alu recombination and two from non-homologous end joining. Conclusions: MLPA is a robust, inexpensive, simple technique that reliably detects both 5q35 microdeletions and partial NSD1 deletions that together account for ∼15% of Sotos syndrome.

To assess at a population-based level the frequency with which severe structural congenital malformations are detected prenatally in Europe and the gestational age at detection, and to describe regional variation in these indicators.In the period 1995-1999, data were obtained from 17 European population-based registries of congenital malformations (EUROCAT). Included were all live births, fetal deaths and terminations of pregnancy diagnosed with one or more of the following malformations: anencephalus, encephalocele, spina bifida, hydrocephalus, transposition of great arteries, hypoplastic left heart, limb reduction defect, bilateral renal agenesis, diaphragmatic hernia, omphalocele and gastroschisis.The 17 registries reported 4366 cases diagnosed with the 11 severe structural malformations and of these 2300 were live births (53%), 181 were fetal deaths (4%) and 1863 were terminations of pregnancy (43%); in 22 cases pregnancy outcome was unknown. The overall prenatal detection rate was 64% (range, 25-88% across regions). The proportion of terminations of pregnancy varied between regions from 15% to 59% of all cases. Gestational age at discovery for prenatally diagnosed cases was less than 24 weeks for 68% (range, 36-88%) of cases. There was a significant relationship between high prenatal detection rate and early diagnosis (P0.0001). For individual malformations, the prenatal detection rate was highest for anencephalus (469/498, 94%) and lowest for transposition of the great arteries (89/324, 27%). Termination of pregnancy was performed in more than half of the prenatally diagnosed cases, except for those with transposition of the great arteries, diaphragmatic hernia and gastroschisis, in which 30-40% of the pregnancies with a prenatal diagnosis were terminated.European countries currently vary widely in the provision and uptake of prenatal screening and its quality, as well as the "culture" in terms of decision to continue the pregnancy. This inevitably contributes to variation between countries in perinatal and infant mortality and in childhood prevalence and cost to health services of congenital anomalies.

Hypophosphatasia is characterized by defective bone mineralization associated with impaired activity of the tissue non-specific alkaline phosphatase (TNSALP) due to mutations in the TNSALP gene. We describe a child with a mutation that has not been described up to now.A 4-year-old child presented with clinical symptoms of rickets and premature loss of decideous teeth. Reduced serum alkaline phosphatase activity and radiographic features led to the diagnosis of hypophosphatasia, which was confirmed by genetic investigation. The molecular study showed two missense mutations, of which one is a novel mutation.Hypophosphatasia is suspected in a child with rickets and premature loss of decideous teeth. Such symptoms should prompt the search of a reduced serum alkaline phosphatase activity. The clinical and molecular diagnosis of the disease is important for the genetic counseling but also for a proper determination of prognosis, as it is related to the type of mutation.

The Marshall-Smith Syndrome (MSS) is a rare disease characterized by orofacial dysmorphism, failure to thrive, accelerated osseous maturation and mental retardation. It has anaesthetic implications due to upper airway problems and possible atlanto-axial instability. We present the perioperative problems (difficult intubation, airway obstruction) encountered in a child with MSS who underwent several anaesthetics during his first two years of life.At birth, the child presented with asphyxia due to obstructive apnoea. His trachea was, therefore, intubated immediately. The morphological diagnosis of MSS was confirmed by the pathognomonic radiological appearance of the bones (bone age was eight months at the age of four days). Upper airway difficulty was caused by functional problems at the level of the hypopharynx (inspiratory collapse at the level of the velum palatinum), and was solved by the use of a nasopharyngeal airway (NPA) during the induction of anaesthesia and early postoperative period.The use of an NPA during both induction and recovery of anaesthesia may be particularly useful to prevent upper airway problems in children with MSS.

A series of 1790 fetal and neonatal autopsies performed between 1976 and 1988 were retrospectively investigated for the presence of hydrops. Thirty (5.5%) and 35 (2.8%) cases of hydrops were found in the groups of fetal and neonatal autopsies, respectively. Genetic causes accounted for 35%. A careful search for previously reported genetic causes of fetal hydrops indicated 64 different etiologies. Twenty-one of them were not mentioned in the previous reviews: these include 9 skeletal dysplasias, 5 inborn errors of metabolism, 3 autosomal recessive, 3 autosomal dominant conditions, and 1 chromosomal abnormality.

The purpose of this study was to compare the changes observed over 4 years in the prenatal diagnosis of genetic diseases and congenital malformations by amniocentesis (AC) and trophoblast biopsy (TB). Between January 1, 1986 and December 31, 1989, 2,591 requests were recorded in a wide geographical area. A general increase in the number of cases per year was observed (414 in 1986, 870 in 1989). The number of requests for TB has distinctly raised in absolute values (14 cases in 1986, 250 in 1989), as well as in relative values compared with AC (3.5% in 1986 40% in 1989). The number of foetal abnormalities detected has tended to diminish with AC (3%) and to increase with TB (4%). At the time of sampling, there was no significant difference in the mothers' mean age between AC (33.9 years) and TB (36.4 years).

The purpose of this review of the literature on nonimmune hydrops fetalis was to evaluate whether recent clinicopathologic studies have modified the relative incidence of the different associated conditions and the management of these pregnancies. We found 600 cases of nonimmune hydrops fetalis published since 1982. These cases were reviewed with particular attention to genetic causes and were compared with a literature review of 298 cases published before 1982. The mean gestational age at diagnosis varied from 24-29 weeks in the recent series, compared with 31-33 weeks in the earlier series. Genetically transmitted conditions accounted for more than 35% of the fetal and maternal disorders associated with nonimmune hydrops fetalis in the recent series, compared with 21% before 1982. The most frequently identified genetic abnormalities in our review were chromosomal disorders (15.7%), alpha-thalassemia (10.3%), skeletal dysplasia (4%), arthrogryposis multiplex syndromes (1.8%), multiple pterygium syndrome (1.5%), and lysosomal storage disorders (1.0%). These results confirm the need for systematic chromosome analysis in fetuses with nonimmune hydrops. From this review, we conclude that prenatal noninvasive and invasive techniques combined with detailed pathologic studies have improved the accuracy of diagnosis of the underlying causes of nonimmune hydrops fetalis and have influenced the management of these pregnancies.

The genetic heterogeneity and the difficulty of accurate genetic counseling in some cases of osteogenesis imperfecta (OI) is shown by the present report. All signs characteristic of OI type II were observed in a newborn infant who died immediately after delivery: curved and deformed limbs, multiple bone fractures, enlarged and soft skull. An autosomal recessive mode is usually admitted for OI type II. However, several cases of OI tarda levis (autosomal dominant) are noticed in the maternal family. The possibility of a relationship between these two types of osteogenesis imperfecta in the same family, which might be important for genetic counselling, is discussed.

Two siblings affected with partial trisomy 3p resulting from a maternal balanced translocation 46,XX t(3;10) (p21;q26) are reported. The clinical features of this syndrome are reviewed. The necropsy findings of the two siblings are discussed.

During the 8 year-period 1971-1978 inclusive, 268 newborn with Down's syndrome (DS) were ascertained in Wallonia (South Belgium). The chromosomes of all patients were analyzed. A standard trisomy 21 was observed in 259 cases (96.6%) and translocations in seven (2.6%). One mosaic (0.4%) and one case with a 47,XX,+21,5 p-karyotype (0.4%) were also found. The overall incidence at birth for the 8 year-period was of 0.123%. However, the comparison of the 2 four-year periods 1971-1974 and 1975-1978 showed an increased incidence in mothers below 35 during the second period, reaching a statistical significant level in Charleroi, and industrial and densely populated area of the region (Fisher's exact test: P = 0.016 less than 0.025). Young women have now become the principal source of DS patients in Wallonia. This change from the previous pattern happened abruptly in 1975, and strongly suggests that one or more persisting factors relating to meiotic non-disjunction of chromosome 21 are operating in this region since 1974, and affecting DS births from 1975 onwards.

This paper outlines the problem of major malformations of the urinary tract, their frequency and their etiology. It is based on data analysis of 900 neonatal autopsies performed in our center from 1978 to 1987. These major malformations are often lethal and they can essentially be separated into disorders of the kidney and malformations of the lower urinary tract. Single-gene disorders are often seen in the former whereas the second group is more likely to be multifactorially controlled. We do insist on the importance of a strict collaboration between pathologists and geneticists.

An image analyzer is described (Quantimet 720 System 20) and its role in histology and cytology is presented with four different examples of measurements: epithelium thickness, liver steatosis, microdensitometry and lymphocyte stimulation. The stress is laid on the way of using the machine and on its advantages rather than on the interpretation of the results.

Data analysis of 600 neonatal necropsies performed in our Center from 1978 to 1984, has shown that in 200 cases one or more lethal malformations were observed: the most frequent concerned the central nervous system (33 cases), the urinary tract system (28 cases) and the cardiovascular system (26 cases). A genetic determinism was considered in 127 cases (63,5%). Usually a genetic counselling follows neonatal death in our Center: necropsy findings are then most useful: the authors advocate the interest of a close collaboration between pathologists and geneticists.

18 cases of trisomies 13, 18, or 21 were diagnosed either by examining the caryotype or on clinical criteria. When the placenta was examined in 60% of cases there was a marked retardation of villous maturation with frequent persistence of embryonic forms of villi. The authors suggest that the failure of the villi to mature was often a reflection of pathology in the oocyte which started to show itself at the beginning of the pregnancy.

In our serie of 450 neonatal necropsies, 26 cases presenting with urinary tract anomalies have been observed (5,7% of the total and 15,5% in those with malformations). From an etiological point of view, two groups could be distinguished: one (17 cases) with severe oligoamnios sequence and the second (9 cases) with hereditary malformations. In this second heterogeneous group thourough pathological examination seems to be the essential for diagnosis and efficient genetic counselling.

The usual indications of amniocentesis for prenatal diagnosis are briefly reviewed. Some situations which are note included in these usual indications are discussed: mothers of 34 years, young aunts of a trisomic child, patients with a previous aborted conceptus diagnosed as trisomic by histological examination of the placenta or tissue culture. It is anticipated that, if accepted, these "unusual" criteria would not overload a given laboratory with an excess of analysis, and would certainly relief anxiety of motivated couples.

The present observation concerns a female patient with a 47,XX, r(18), + mar karyotype. The size of the ring varies from mitosis to mitosis; generally it is very small. The presence of a small marker ("minute") may explain some phenotypic differences not usually observed in the "r(18) syndrome". This patient is the niece of a trisomic 21, who showed complex chromosome anomalies during the course of an acute leukemia from which he died.

Congenital anomalies or malformations have now become the principal cause of neonatal deaths, as confirmed by the present study of 350 consecutive autopsies studied from 1977 to 1981. The overall incidence of congenital malformations for the whole period considered was of 36.8%. However, during this short four-year lapse of time, a steady increase from 26.8% in 1977 to 48.1% in 1981 could be noticed. This increase is concomitant to the decrease of the "classical" causes of neonatal deaths, namely prematurity sequellae and intrapartal death. Indeed, many different entities have been identified; it seems interesting to point out, however, the relatively great number of autosomal recessive diseases found in the present series. For a full genetic profit, neonatal autopsy should be complete and systematically followed by genetic counseling.

In the province of Hainaut (Belgium), a study was undertaken in order to assess a pediatric pathology department, organized at the regional level. The study concerned 182 perinatal deaths, occurring among the 16,071 births in 9 maternity hospitals, in 1982 and 1983. The frequency of autopsies was 51%, both for stillbirths and for early neonatal deaths. It was 76% in the group of deaths related to congenital malformations and 48% in the group of deaths of unknown cause. The lack of an autopsy was explained in 20% of cases by the parents' refusal, in 8% of cases by the state of maceration of the fetus and by the obviousness of the diagnosis in 24%. In 46% of cases, no etiology was found and it appeared that the degree of physician interest was an important factor in the frequency of autopsies. Dissection alone revealed the cause of death in 13 of the 94 autopsies. In children presenting with congenital malformations, the performance of a complete pathologic study almost always led to genetic counseling for the parents. This counseling was almost never given when autopsy was not performed.

With the recently introduced chorionic villi sampling techniques, the study of fetal chromosomes during the first trimester of pregnancy has become possible. After the biopsy has been performed, the length of time necessary to obtain suitable mitoses for karyotype analysis varies from a few hours with the direct technique (Simoni et al. 1983) to 10–21 days (mean, 16 days) with tissue cultures of macerated villi (Heaton et al. 1984). From the histologic point of view, a single villus of the first trimester shows a mesenchymal core, which is surrounded by a inner layer of cytotrophoblast and an outer layer of syncytiotrophoblast and ends with a dense cytotrophoblastic cell column (Boyd and Hamilton 1970). Dividing cells are observed in the mesenchymal core and the cytotrophoblast; to the contrary, the syncytiotrophoblast shows no mitoses. Shortly after biopsy, DNA synthesis, as demonstrated by tritiated thymidine incorporation, occurs in the cytotrophoblast and the villous core (Gerbie et al. 1968); this activity persists several days in vitro.

Meiotic chromosome studies in male infertility are controversial: some authors find them useful, others do not. Indeed, interpretation of data already published is still difficult, for some main reasons discussed in the text: the small volume of testicular tissue available for observation, the lack of uniformity in the selection of patients from series to series, the presentation of the results. Nevertheless, critical analysis of the literature leads to the conclusion that in 10% of patients whom underwent testicular biopsy, meiotic chromosome anomalies can easily explain their infertility. Our personal series of 450 cases confirms this order of magnitude. Therefore, we think that meiotic chromosome analysis is certainly useful in the evaluation of male infertility, both for diagnosis and prognosis.

This paper outlines the problem of major malformations of the urinary tract, their frequency and their etiology. It is based on data analysis of 900 neonatal autopsies performed in our center from 1978 to 1987. These major malformations are often lethal and they can essentially be separated into disorders of the kidney and malformations of the lower urinary tract. Single-gene disorders are often seen in the former whereas the second group is more likely to be multifactorially controlled. We do insist on the importance of a strict collaboration between pathologists and geneticists.

The authors report an unusual case of major lung hypoplasia in both of twins without any other associated malformations. This case has given an opportunity to make a hypothesis on the aetiology and pathogenesis in order to try to explain the pathology and better to appreciate fetal respiratory function.

Between 1974 and 1987, 232 translocation carriers have been detected in our Center; they belong to 144 different families. Indications for chromosome analysis were the following: familial studies in relation with a patient suggesting a chromosome anomaly (25.4%); mental retardation with or without malformations (24.6%); 2 or more spontaneous abortions (17.2%); infertility problems, mainly male (16.4%); genetic counseling for a non-chromosomal disease (9.5%); prenatal diagnosis in risk pregnancies (6.9%). The chromosome anomalies detected were the following; balanced Robertsonian fusions (114 cases = 49.1%); balanced translocations (74 cases = 31.9%); unbalanced translocations, Robertsonian fusions included (44 cases = 19%). Two groups may be distinguished: the first one confirms data already known, such as high frequency of balanced translocations in couples with multiple abortions, or in infertile males. The second group on the contrary shows more unusual observations: 4 cases of standard trisomy 21 born to young parents carriers of a balanced translocation not involving chromosome 21; 5 cases of trisomy 13 with 46 chromosomes and a Robertsonian fusion, born to parents carriers of a t(13q; Dq) (twice the mother and thrice the father); 14 cases of apparently balanced translocations, however with an abnormal phenotype; and finally 22 cases of balanced translocations incidentally detected during the course of investigations in patients with a genetic problem generally not associated with a chromosome defect.

The EUROCAT programme is a concerted action of the European Economic Community for the epidemiologic surveillance of congenital anomalies. Surveillance is based on a network of regional registries coordinated by a central registry. The programme started in 1979 and by 1987, 23 centres were participating, covering together more than 300,000 births per year. The surveillance process implies the selection of the anomalies possibly associated with environmental teratogens or mutagens, the definition of abnormal variations in the rate of these anomalies (the alarms), the establishment of base-line rate and the continuous monitoring of rate. The programme is evaluated by reference to four criteria: the sensitivity of the system in detecting teratogens or mutagens, the specificity of alarms, the rapidity in warning of alarm and in investigating their causes, and the programme efficiency expressed as its cost-utility ratio.

Five hundred children and adolescents affected by mild mental retardation were studied together with their families with regard to a number of psycho-social, medical and genetic factors. Statistical studies were performed with these data and showed that this apparently homogeneous population could in fact be divided into three subgroups. The first and by far the largest group (66%) was constituted by a clinically normal population but in whom adverse social and cultural factors were dominant. In the second subgroup (20%) the mental retardation was much more pronounced (IQ of 50----65) and the socio-cultural and socio-economic levels were particularly low. Finally, organic causes (prematurity, dystocic, labour, etc.) seemed to constitute the principal factor explaining the retardation observed in the third subgroup (14%). The second subgroup comprising of 50 children and their families, were observed more closely; in this group 20 cases of known genetic diseases were found.