Localization of major histocompatibility complex class I and II mRNA in human first-trimester chorionic villi by in situ hybridization.

Maternal immune recognition of pregnancy occurs despite the nonexpression of classical major histocompatibility complex (MHC) antigenic determinants by chorionic villous trophoblast, which comprise the major surface area where maternal blood contacts fetal-derived cells. cDNA-mRNA in situ hybridization was used to probe expression of transcripts corresponding to nonpolymorphic MHC determinants in first-trimester chorionic villus samples. The HLA-B7 probe hybridization signals were localized to syncytiotrophoblast and to cells of the mesenchyme but not to villous cytotrophoblast. HLA-G mRNA was found only in syncytiotrophoblast. A DR beta clone hybridized to both villous cytotrophoblast and syncytiotrophoblast. The results suggest that expression of trophoblast class I and class II determinants early in gestation (10 wk) may be regulated by posttranscriptional events. This also suggests the potential for maternal antifetal alloimmune responses.

Autosomal dominant inheritance of annular pancreas.

This report describes a family with apparent autosomal dominant transmission of congenital annular pancreas. Four individuals in two generations were affected; all developed duodenal obstruction. The implications for genetic counseling are discussed.

Growth manifestations in the Brachmann-de Lange syndrome.

We have obtained serial measurements on 180 patients with clinically confirmed Brachmann-de Lange syndrome (BDLS) in order to derive standard growth curves. The patients were evaluated in our genetics department and through meetings of the Cornelia de Lange Syndrome Foundation, a support group for families of affected individuals. The data were obtained from the records of pediatricians, other physicians, schools and parents, as well as from personal examination on each of these patients at least once, often periodically. The growth curves include height, weight and head circumference measurements from birth through adulthood. Prenatal growth and birth weights are below the 5th centile in most (68%) cases, with an average birth weight of 2,277 g. Growth persists below the normal curves in most of the patients throughout life. Height velocity is equal to the normal range but there is slower pubertal growth. Weight velocity is below the normal range throughout life until late adolescence. Average head circumference remains below the second centile. Thin body habitus coupled with slow growth and proportionate small stature is a manifestation of the syndrome, but is commonly mistaken for failure to thrive.

Repeated pregnancy loss.

Debate persists over the value of chromosome analysis of couples with repeated pregnancy loss. Therefore, we studied the records of all patients referred to the Genetics Division at Thomas Jefferson University for repeated pregnancy loss. Couples were divided into three groups according to the reason for evaluation. In group I (two consecutive abortions) significant chromosome abnormalities were found in 1.8% of individuals; in group II (three or more consecutive abortions) 2.3% of individuals had a chromosome abnormality; and in group III (50% fetal loss) 1.8% of persons had abnormal chromosomes. These rates are lower than those reported by others, but are still ten times higher than those expected in the general population and affirm the value of doing a chromosome study in such couples. In addition, we found increased incidence of liveborn offspring with congenital abnormalities in couples evaluated for the above indications, and found a high incidence of a family history of repeated suboptimal pregnancy outcome. The significance of these findings is discussed.

Genetic syndromes and uniparental disomy: a study of 16 cases of Brachmann-de Lange syndrome.

Uniparental disomy is responsible for a proportion of cases in Prader-Willi, Angelman, and Wiedemann-Beckwith syndromes. In these syndromes, the chromosomes involved are thought to contain one or more imprinted genes. When two copies of the imprinted (inactivated) gene are inherited from a single parent through uniparental disomy or the active gene is deleted, the phenotype of the syndrome results. Our goal is to identify additional syndromes caused by uniparental disomy. Our approach is to select syndromes that appear to have more than one mode of inheritance and are occasionally associated with a cytogenetic abnormality. Given this criterion, we have chosen Brachmann-de Lange Syndrome (BDLS) to investigate since the phenotype is similar to that found in patients with dup(3q). We have studied 16 probands with BDLS and their parents using a multiplex of four PCR-based polymorphic loci on chromosome 3. None of the probands studied had uniparental disomy for chromosome 3 and all demonstrated normal biparental inheritance for at least one locus. Given these results, uniparental disomy of chromosome 3 does not appear to be a major contributor to the syndrome. Additionally, both maternally and paternally derived chromosome abnormalities have resulted in the dup(3q) phenotype and dominant inheritance of BDLS from both mildly affected mothers and fathers have been reported which suggests that imprinting is not involved in these syndromes.

New X-linked mental retardation disorder with Dandy-Walker malformation, basal ganglia disease, and seizures.

We report on a 4 generation family of individuals with an X-linked form of mental retardation involving 9 affected males and 5 obligate carrier females. Key manifestations include severe mental retardation, early hypotonia with progression to spasticity and contractures, choreoathetosis, seizures, presence of a long, narrow face with coarse features, cystic enlargement of the fourth ventricle with cerebellar hypoplasia (Dandy-Walker malformation), and iron accumulation in the basal ganglia with neuroaxonal dystrophy similar to Hallervorden-Spatz disease. Of the 5 known heterozygotes, 3 are dull intellectually, and one of the 3 developed a "presenile dementia." At autopsy she had iron deposition and neuroaxonal dystrophy in the basal ganglia and atrophy of the cerebral cortex. Although the clinical findings among relatives are variable, we conclude that this is a distinct, previously unrecognized X-linked mental retardation syndrome.

Sixty-four patients with Brachmann-de Lange syndrome: a survey.

We surveyed 64 individuals with the diagnosis of Brachmann-de Lange syndrome (BDLS) to determine the natural course and cause of the disorder. The 64 individuals were ascertained through membership in a national organization, the Cornelia de Lange Syndrome (CDLS) Foundation, comprised of families who have a relative with BDLS. We surveyed 64 families by questionnaire and personally examined 24 of the 64. Our data suggest that lower birth weight correlates with a more severe phenotype, specifically including severe upper limb malformations and greater psychomotor retardation. The lower birth weight group showed a significant excess of females. The miscarriage rate was normal and there were no recurrences reported in the 64 families we surveyed. Major management problems included feeding problems and projectile vomiting, behavioral problems including frequent tantrums, hearing and dental difficulties, and recurrent respiratory tract infections. The oldest, teenaged subjects in our study entered puberty; although pregnancy has not been reported in the syndrome, it is likely that people with BDLS are fertile. Though most BDLS children reared at home survive through adolescence, a significant degree of psychomotor retardation and difficult medical management problems still occur.

Developmental data on individuals with the Brachmann-de Lange syndrome.

One hundred twenty-two patients with clinically confirmed Brachmann-de Lange syndrome (BDLS) were evaluated developmentally. Recruitment was made from our genetics department and through meetings of the Cornelia de Lange Syndrome Foundation parent support group. Developmental information was obtained from records of physicians, schools and developmental centers, or from parents on each of the 122 individuals, allowing division into four groups for study: group 1 (n = 48) underwent formal developmental assessments, which generated intelligence or developmental quotients, and had a completed parental questionnaire with specific developmental questions regarding ages of skills mastered; group II (n = 23) had additional developmental records available without formal testing, as well as the questionnaire; group III (n = 22) had only a completed questionnaire; and group IV (n = 29) had formal developmental testing or other developmental records but no available questionnaire. These data were analyzed in order to be able to predict attainable psychomotor development. Average scores on formal testing were found to be in the mild to moderate level of mental retardation, ranging from below 30 to 85, with an average intelligence quotient of 53, higher than previously reported. Visual-spatial memory and perceptual organization skills were found to be strengths. Younger individuals born before 1980 demonstrated higher scores on testing. Early intervention appears to play a major role in the level of developmental achievement.

X-linked motor-sensory neuropathy type-II with deafness and mental retardation: a new disorder.

We report on a family with an apparently X-linked neuromuscular disease. Electrophysiologic tests and electron microscopic studies are consistent with the diagnosis of hereditary motor sensory neuropathy type II (HMSN-II), one form of Charcot-Marie-Tooth disease. The manner of inheritance, the observation that males are severely affected from infancy, and the frequent association of deafness and/or mental retardation with the neuromuscular disorder are not usual for HMSN-II and suggest that this family may have a previously undescribed genetic disorder. The peripheral neuropathy did not appear to be linked to the Xg blood group. Minor abnormalities of sensory nerve conduction, electromyography, and hearing were separately identified in female relatives in this family, but were not consistent enough to be useful in the identification of carriers for this gene.

Ring chromosome 4 mosaicism coincidence of oligomeganephronia and signs of Seckel syndrome.

We present a patient with features suggestive of Seckel syndrome who was found to be mosaic for ring 4 chromosome. Seckel syndrome is a rare entity characterized by marked growth retardation, microcephaly, facies characterized by receding forehead and chin, large beaked nose, and severe retardation, usually thought to be inherited as an autosomal recessive condition. In addition, our patient had oligomeganephronia, a rare and usually sporadic renal malformation, previously reported in two other patients with abnormalities of chromosome 4. Besides pointing out the overlap between the Seckel phenotype and Wolf-Hirschhorn syndrome, our patient illustrates the need to consider cytogenetic studies in patients with the Seckel phenotype, so that accurate diagnoses can be given to families. Also, the case suggests that there may be a locus for oligomeganephronia distal to the Wolf-Hirschhorn critical region on 4p.

Prenatal diagnostic techniques. Chorionic villus sampling.

Chorionic villus sampling (CVS) is a new prenatal diagnostic technique which is performed in the first trimester of pregnancy. Traditional methods of prenatal diagnosis, including amniocentesis and fetoscopy, must be performed in the midtrimester. In concert with the development of DNA methods of fetal cell analysis, first trimester fetal diagnosis utilizing CVS offers many advantages over traditional mid-trimester techniques. In addition, CVS may potentially allow therapeutic intervention to prevent or ameliorate some congenital defects.

Diagnostic use of meternal serum alpha-fetoprotein levels.

Alpha-fetoprotein (AFP) levels in human maternal serum were elevated in 14 patients when measured by a radioimmunoassay. In 8 patients the elveated serum levels of AFP correlated with increased concentration of AFP in amiotic fluid and were diagnostic of fetal defects. The elevated AFP levels in the remaining 6 patients were shown to be the result of fetomaternal transfusion from either amniocentesis or natural causes. Serum samples drawn after amniocentesis through an anterior placenta may show false-positive elevations. The use of both maternal serum and amniotic fluid samples in pregnancies at high risk for neural tube defects can decrease the risk of diagnostic errors due to mistakes in gestational datind and may increase the diagnostic sensitivity of amniocentesis.

PIP: 14/150 patients studied over a 2-year span had elevated serum alpha fetoprotein (AFP) in the course of pregnancy; fetal abnormality or a source of fetomaternal transfusion was present in each case. The fetomaternal transfusions generally resulted from amniocentesis through an anterior placenta. In 4 cases, fetal demise with fetal maceration occurred. In 3 of these, amniotic fluid AFP concentrations were 10 times the normal for that gestational week. Sequential serum AFP rose to nearly twice the initial value in 1-3 weeks. In 3 cases, the fetuses had neural tube defects, and in each case both amniotic fluid and maternal serum AFP were elevated. In 5 cases with initially false positive serum elevations not accompanied by elevated amniotic fluid AFP, fetomaternal transfusion resulting from amniocentesis was the cause; in all, 7 cases of maternal serum elevation secondary to fetomaternal transfusion were recorded. Analyzing both maternal serum and amniotic fluid samples in pregnancies at high risk for neural tube defects can decrease diagnostic errors caused by mistakes in gestational dating and may increase the diagnostic sensitivity of amniocentesis.

Mosaicism in chorionic villus sampling: an association with poor perinatal outcome.

Prenatal diagnosis by first-trimester chorionic villus sampling was successful in 4319 pregnancies involving 4395 fetuses. Cytogenetic information was obtained by both rapid cytotrophoblastic preparation and monolayer mesenchymal tissue culture. Chromosomal mosaicism was present in 55 of 4319 (1.3%). The abnormal cell line involved the cytotrophoblast in 79.6% of the mosaic specimens. None of the abnormalities found in the cytotrophoblast were confirmed in the fetus when the tissue culture was normal, supporting the belief that the cells of the mesenchymal core more truly reflect the chromosomal constitution of the fetus. However, a significant increase in the perinatal loss rate in the placental mosaic group was noted when compared with the nonmosaics: 16.7 versus 2.7% (P = .0001). These findings suggest that placental mosaicism may be a cause of perinatal loss.

Ultrasonographic parameters in the prenatal diagnosis of Meckel syndrome.

The ability to make a prenatal diagnosis of Meckel syndrome (encephalocele, polydactyly, and polycystic kidney) by ultrasound is described. Three cases are detailed; in 2 of these the diagnosis was made at 18 and 36 weeks' gestation, respectively. In case 1 Meckel syndrome was identified by the presence of oligohydramnios, microcephaly, and enlarged cerebral ventricles. In case 2 oligohydramnios was associated with an encephalocele, bilateral renal enlargement, and a polydactyly. In case 3 the diagnosis was excluded in a fetus at risk. The usefulness of ultrasound in making this diagnosis is discussed for cases in which the amniotic fluid alpha-fetoprotein value is normal, inconclusive, or unobtainable.

Late first-trimester invasive prenatal diagnosis: results of an international randomized trial.

OBJECTIVE: To assess, in a randomized trial, the safety and accuracy of amniocentesis and transabdominal chorionic villus sampling (CVS) performed at 11-14 weeks of gestation, given that this time frame is increasingly relevant to early trisomy screening. METHODS: We compared amniocentesis with CVS from 77 to 104 days of gestation in a randomized trial in a predominantly advanced maternal age population. Before randomization, the feasibility of both procedures was confirmed by ultrasonography, and experienced operators performed sampling under ultrasound guidance; conventional cytogenetic analysis was employed. The primary outcome measure was a composite of fetal loss plus preterm delivery before 28 weeks of gestation in cytogenetically normal pregnancies. RESULTS: We randomized 3,775 women into 2 groups (1,914 to CVS; 1,861 to amniocentesis), which were comparable at baseline. More than 99.6% had the assigned procedure, and 99.9% were followed through delivery. In contrast to previous thinking, in the cytogenetically normal cohort (n = 3,698), no difference in primary study outcome was observed: 2.1% (95% confidence interval 1.5, 2.8) for CVS and 2.3% (95% confidence interval, 1.7, 3.1) for amniocentesis. However, spontaneous losses before 20 weeks and procedure-related, indicated terminations combined were increased in the amniocentesis group (P =.07, relative risk 1.74). We found a 4-fold increase in the rate of talipes equinovarus after amniocentesis (P =.02) overall and in week 13 (P =.03, relative risk = 4.65), but data were insufficient to determine this risk in week 14. CONCLUSION: Amniocentesis at 13 weeks carries a significantly increased risk of talipes equinovarus compared with CVS and also suggests an increase in early, unintended pregnancy loss. LEVEL OF EVIDENCE: I

Translocation (X;19) with involvement of the inactive X chromosome in oligoblastic granulocytic leukemia.

A 72-year-old female with metastatic breast cancer developed oligoblastic granulocytic leukemia 6 months after initiation of chemotherapy. Cytogenetic examination of the bone marrow cells revealed a balanced t(X;19)(q12;q13.3) as the sole abnormality in 50% of the metaphases. The remaining cells showed a normal female karyotype. The der(19) chromosome displayed consistent folding in the Xq13-q23 region in all metaphases, indicating involvement of the inactive X chromosome in translocation.

Chromosome errors as a cause of spontaneous abortion: the relative importance of maternal age and obstetric history.

OBJECTIVE: To evaluate the likelihood of obtaining a chromosome diagnosis in cases of spontaneous abortion (SAB) and of the relative importance of maternal age versus obstetric history in predicting the fetal karyotype. DESIGN: Obstetric history was obtained from all 100 cases of miscarriage in 1 year when products of conception were sent for chromosome studies. Multiple logistic regression analysis was used to calculate odds ratio and statistical significance for correlations between historical factors and the probability of any chromosomal abnormality or trisomy. RESULTS: A chromosome diagnosis was made in 84% of cases. Maternal age was a more important predictor of chromosome abnormality, specifically trisomy, than history of previous livebirths or miscarriages. CONCLUSION: Results from chromosome studies using chorionic villi from SABs are diagnostically useful, even when the patient has a history of repeated miscarriages.

The effect of the elapsed time between blood draw and processing on the recovery of fetal cells from maternal blood.

OBJECTIVE: To test the hypothesis that a delay in initial fetal cell enrichment processing of maternal blood samples (defined as the time between blood draw and the initial density gradient centrifugation step) compromises the ability to recover fetal cells, we performed a randomized comparison of immediate (within 4 hours of draw) versus delayed (between 18-24 hours of draw) processing. METHODS: Four centers participated: two centers utilized flow cytometry (FLOW), and two centers utilized magnetic-activated cell sorting (MACS) techniques. Each center collected 34 samples. The outcome was the percentage of gamma positive (gamma(+)) cells for FLOW or the number of nucleated red blood cells (NRBCs) for MACS, found in the final enriched cell population. Both outcomes reflect cell properties that are potentially fetal in origin, thus making them representative of the ability to recover fetal cells. RESULTS: Our results did not support our hypothesis that delay in processing compromises fetal cell recovery. Instead, in MACS processing, we observed an increase in recovered NRBCs when blood sample processing was delayed compared with immediate processing. There was no significant difference in gamma(+) cells with FLOW. CONCLUSION: Time-related changes in the density of target cells, perhaps associated with their progress towards apoptosis during the delay period, may result in increased intact fetal cells with the study methods utilized.

Prenatal diagnosis of neurolipidoses.

While there is no single best procedure for performing prenatal diagnosis, ther is a rationale or strategy which will produce correct, reliable results. The investigator should be experienced with all the tests and know what to expect from each. At least two of these tests should e used (more if there s ambiguity) on amniotic fluid and cultured cell extracts. Which tests, and how many, are not as important as the skill and experience of the investigator performing them. Proper controls should be used. Probably the biggest single factor in successful prenatal diagnosis is the use of both negative and positive controls run simultaneously. No method, no matter how good or how well performed, can be counted upon to give sufficiently reproducible results to interpret without these controls. Finally, it is necessary for the investigator to be thoroughly familiar with the enzyme and its isozymes and the clinical heterogeneity of the disease. Although the foregoing details pertain specifically to Tay-Sachs disease, similar or related problems exist in the prenatal diagnosis of any of the neurolipidoses. The need for care of the samples, appreciation of biochemical and clinical heterogeneity, the need for adequate techniques, and the importance of proper controls are requirements for diagnosing any of the neurolipidoses.

Suspected genetic disease.

To formulate an accurate diagnosis and provide adequate management of genetic problems associated with ear malformations or hearing loss, the otolaryngologist must have an awareness of possible genetic causes of these disorders. Careful evaluation of the family history as well as examination or testing of family members might be required to arrive at a correct diagnosis. The clinical geneticist can provide assistance to the clinician with contemporary information about additional useful diagnostic studies, the possibility of prenatal diagnosis of the disorder, or in the process of genetic counseling so as to enhance the family's overall adjustment to the problem.