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Chorionic villus sampling (CVS) was performed on a 40-year-old woman at 9 1/2 menstrual weeks because of advanced maternal age. The direct preparation showed 46,XY,dup(10)(q11.2q23.2). CVS long-term culture and fetal tissue revealed a rare additional abnormality: 48,XXXY,dup(10)(q11.2q23.2). This abnormality represented the major cell line (>85 per cent in 691 cells) in an (XY)/XXY/XXXY/(XXXXY) mosaic (all cell lines presumably bearing the dup(10q); the presence of XY and XXXXY cell lines is uncertain). To our knowledge, this is the first report of trisomy 10q11-q23 and of prenatally detected 48,XXXY in chorionic villi. The mosaic could have resulted from early post-zygotic non-disjunctions in a 46,XY,dup(10q) or 47,XXY,dup(10q) zygote. The results from DNA studies of four polymorphisms, mapped to Xp and Xq, support this theory. The literature on prenatally detected cases with sex chromosome tetrasomy and pentasomy and those with additional autosomal abnormalities is reviewed. The reported case underlines the problem of false-negative findings when only direct CVS preparations are karyotyped.

Chromosome 8p23.1 is a common hotspot associated with major congenital malformations, including congenital diaphragmatic hernia (CDH) and cardiac defects. We present findings from high-resolution arrays in patients who carry a loss (n = 18) or a gain (n = 1) of sub-band 8p23.1. We confirm a region involved in both diaphragmatic and heart malformations. Results from a novel CNVConnect algorithm, prioritizing protein-protein interactions between products of genes in the 8p23.1 hotspot and products of previously known CDH causing genes, implicated GATA4, NEIL2, and SOX7 in diaphragmatic defects. Sequence analysis of these genes in 226 chromosomally normal CDH patients, as well as in a small number of deletion 8p23.1 patients, showed rare unreported variants in the coding region; these may be contributing to the diaphragmatic phenotype. We also demonstrated that two of these three genes were expressed in the E11.5-12.5 primordial mouse diaphragm, the developmental stage at which CDH is thought to occur. This combination of bioinformatics and expression studies can be applied to other chromosomal hotspots, as well as private microdeletions or microduplications, to identify causative genes and their interaction networks. © 2012 Wiley Periodicals, Inc. ispartof: American Journal of Medical Genetics A vol:158 issue:12 pages:3148-3158 ispartof: location:United States status: published

AIM: In an earlier study we have shown that transcervical chorionic villus sampling in excess of 90 mg increases the risk for hemangiomas of infancy three- to four-fold compared to amniocentesis. In the present study we investigated whether transabdominal chorionic villus sampling (TA-CVS), in which the samples are smaller, carries the same risk. MATERIAL AND METHODS: Retrospectively, data were analyzed from 200 consecutive TA-CVS procedures and 200 consecutive amniocentesis procedures. Forty-two TA-CVS procedures and 27 amniocentesis procedures were excluded on predefined criteria. Questionnaires were sent to the parents asking if there was any skin mark on the child: vascular, pigmented or otherwise. All hemangiomas were clinically confirmed. RESULTS: In the TA-CVS group, 118/158 questionnaires (75%), and in the amniocentesis group 134/173 questionnaires (77%) were returned. Based on the results of the questionnaire (i.e. mentioning of any skin lesion), 24 children in the TA-CVS group and 42 children in the amniocentesis group qualified for a physical examination. In the TA-CVS group 11/118 children (9%) had one or more hemangiomas. In the amniocentesis group 6/134 children (4%) had one or more hemangiomas. There was no statistical difference between the two groups (P = 0134). CONCLUSION: These results suggest that TA-CVS does not cause an increase in the prevalence of hemangioma compared to amniocentesis. A larger series is, however, necessary to confirm this

AIM: In an earlier study we have shown that transcervical chorionic villus sampling in excess of 90 mg increases the risk for hemangiomas of infancy three- to four-fold compared to amniocentesis. In the present study we investigated whether transabdominal chorionic villus sampling (TA-CVS), in which the samples are smaller, carries the same risk. MATERIAL AND METHODS: Retrospectively, data were analyzed from 200 consecutive TA-CVS procedures and 200 consecutive amniocentesis procedures. Forty-two TA-CVS procedures and 27 amniocentesis procedures were excluded on predefined criteria. Questionnaires were sent to the parents asking if there was any skin mark on the child: vascular, pigmented or otherwise. All hemangiomas were clinically confirmed. RESULTS: In the TA-CVS group, 118/158 questionnaires (75%), and in the amniocentesis group 134/173 questionnaires (77%) were returned. Based on the results of the questionnaire (i.e. mentioning of any skin lesion), 24 children in the TA-CVS group and 42 children in the amniocentesis group qualified for a physical examination. In the TA-CVS group 11/118 children (9%) had one or more hemangiomas. In the amniocentesis group 6/134 children (4%) had one or more hemangiomas. There was no statistical difference between the two groups (P = 0134). CONCLUSION: These results suggest that TA-CVS does not cause an increase in the prevalence of hemangioma compared to amniocentesis. A larger series is, however, necessary to confirm this

Netherton syndrome (NS) is a severe skin disease caused by loss-of-function mutations in SPINK5 (serine protease inhibitor Kazal-type 5) encoding the serine protease inhibitor LEKTI (lympho-epithelial Kazal type-related inhibitor). Here, we disclose new SPINK5 defects in 12 patients, who presented a clinical triad suggestive of NS with variations in inter- and intra-familial disease expression. We identified a new and frequent synonymous mutation c.891C>T (p.Cys297Cys) in exon 11 of the 12 NS patients. This mutation disrupts an exonic splicing enhancer sequence and causes out-of-frame skipping of exon 11. Haplotype analysis indicates that this mutation is a founder mutation in Greece. Two other new deep intronic mutations, c.283-12T>A in intron 4 and c.1820+53G>A in intron 19, induced partial intronic sequence retention. A new nonsense c.2557C>T (p.Arg853X) mutation was also identified. All mutations led to a premature termination codon resulting in no detectable LEKTI on skin sections. Two patients with deep intronic mutations showed residual LEKTI fragments in cultured keratinocytes. These fragments retained some functional activity, and could therefore, together with other determinants, contribute to modulate the disease phenotype. This new founder mutation, the most frequent mutation described in European populations so far, and these unusual intronic mutations, widen the clinical and molecular spectrum of NS and offer new diagnostic perspectives for NS patients.Journal of Investigative Dermatology advance online publication, 17 November 2011; doi:10.1038/jid.2011.366.

Objectives To test the fetal profile (FP) line, defined as the line that passes through the anterior border of the mandible and the nasion, as a reference line for forehead and mandible anomalies. Methods Volumes of 248 normal and 24 pathological fetuses (1636 and 1937?weeks gestation, respectively) were analysed retrospectively. When the FP line passes anteriorly, across or posteriorly to the frontal bone, this was defined as negative, zero or positive, respectively. When the FP line was positive the distance (F distance) between the FP line and the frontal bone was measured. Results No cases with a negative FP line were found in the normal fetuses. Before 27?weeks gestation the FP line was always zero except in one case. After 27?weeks gestation the FP line was positive in up to 25% (F distance (mean, range): 2.8, 2.13.6?mm). The FP line correctly identified 13 cases with retrognathia, 5 cases with frontal bossing and 3 cases with a sloping forehead. Conclusion Although large prospective studies are needed, the FP line may be a useful tool to detect second trimester profile anomalies such as retrognathia, sloping forehead and frontal bossing with the possibility of quantifying the latter. (c) 2012 John Wiley & Sons, Ltd.

We evaluated first-trimester maternal serum alpha-fetoprotein (MS-AFP) as a marker for fetal chromosomal disorders. The multicentre study was performed under the auspices of the Dutch Working Party on Prenatal Diagnosis. MS-AFP was measured in 2404 normal pregnancies and 72 chromosomally abnormal pregnancies. The median multiple of the normal median (MOM) in 32 Down's syndrome pregnancies was 0.83 with a 95 per cent confidence interval ranging from 0.60 to 1.04. The difference between the distributions of first-trimester MS-AFP in normal and Down's syndrome pregnancies was statistically significant (t-test: t = 2.34, P

Prenatal typing for the human platelet antigens-l (HPA) permits identification of a fetus at risk for neonatal alloimmune thrombocytopenia (NAITP) in cases of HPA-1 incompatibility in which the father is heterozygous for the HPA-la antigen. Diagnostic cordocentesis and phenotyping of the fetal platelets are used for this purpose. We applied allele-specific restriction enzyme analysis on polymerase chain reaction (PCR)-amplified DNA purified from amniocytes. This assay allows early second trimester typing for HPA-1 alleles. We were able to determine the genotype of three fetuses at risk. Iatrogenic fetal loss is lower with amniocentesis than with cordocentesis. Therefore, this technique is a welcome addition to the antenatal management of NAITP.

Prenatal typing for the human platelet antigens-1 (HPA) permits identification of a fetus at risk for neonatal alloimmune thrombocytopenia (NAITP) in cases of HPA-1 incompatibility in which the father is heterozygous for the HPA-1a antigen. Diagnostic cordocentesis and phenotyping of the fetal platelets are used for this purpose. We applied allele-specific restriction enzyme analysis on polymerase chain reaction (PCR)-amplified DNA purified from amniocytes. This assays allows early second trimester typing for HPA-1 alleles. We were able to determine the genotype of three fetuses at risk. Iatrogenic fetal loss is lower with amniocentesis than with cordocentesis. Therefore, this technique is a welcome addition to the antenatal management of NAITP.

Background Junctional epidermolysis bullosa, type Herlitz (JEB-H) is a lethal, autosomal recessive blistering disease caused by null mutations in the genes coding for the lamina lucida/densa adhesion protein laminin-332 (LAMB3, LAMA3 and LAMC2). Objectives To present the diagnostic features and molecular analyses of all 22 patients with JEB-H in the Dutch Epidermolysis Bullosa Registry between 1988 and 2011, and to calculate the disease incidence and carrier frequency in the Netherlands. Methods All patients were analysed with immunofluorescence antigen mapping (IF), electron microscopy (EM) and molecular analysis. Results The mean lifespan of our patients with JEB-H was 5 8 months (range 0.5-32.6). IF showed absent (91%) or strongly reduced (9%) staining for laminin332 with monoclonal antibody GB3. In EM the hemidesmosomes and sub-basal dense plates were hypoplastic or absent. We identified mutations in all 22 patients: in 19 we found LAMB3 mutations, in two LAMA3 mutations, and in one LAMC2 mutations. We found three novel splice site mutations in LAMB3: (i) c. 292A> G resulting in an out-of-frame skip of exon 3 and a premature termination codon (PTC); (ii) c. 1289-2_1296del10 leading to an out-of-frame skip of exon 12 and a PTC; and (iii) c. 3228+ 1G> T leading to an exon 21 skip. Conclusions All diagnostic tools should be evaluated to clarify the diagnosis of JEBH. We have identified 11 different mutations in 22 patients with JEB-H, three of them novel. In the Netherlands the incidence rate of JEB-H is 4.0 per one million live births. The carrier frequency of a JEB-H mutation in the Dutch population is 1 in 249.

Objective In this article, we reflect on whether randomized controlled trials (RCTs) are adequate for the clinical evaluation of maternal-fetal surgery for congenital diaphragmatic hernia (CDH), focusing on the role of patients' preferences in the setting up of research protocols, on the requirement of equipoise and on the concept of therapeutic misconception (TM). Method We describe the conception and setting up of the tracheal occlusion (TO) to accelerate lung growth trial and analyze the ethical dilemmas faced by the research team during that time. Results Depending on the view adopted regarding the scope of equipoise, there are two ways of dealing with patient's preferences concerning fetoscopic endoluminal TO and expectant management during pregnancy for CDH. Conclusion The solution adopted for fetoscopic endoluminal tracheal occlusion (FETO) is justified by the extended period of time it has been available to patients before the start of the RCT. Strong patient and referring physician preferences do not entail a right to have FETO, since it is a procedure of yet unproven efficacy and safety. In the future, to avoid the dilemmas posed by the TM and in name of the right of future generations of patients to have access to treatment of proven safety and efficacy, researchers must be able to plan RCT in due time. Copyright (C) 2011 John Wiley & Sons, Ltd.

Objective To define sonographic criteria that may improve the prenatal diagnosis of Noonan syndrome by targeted DNA testing.Methods We searched our Fetal Medicine Unit records for all cases with a final diagnosis of Noonan syndrome. A literature review was undertaken to identify the sonographic features of Noonan syndrome fetuses. Information was pooled to define the most common features.Results In our database, we identified three cases of Noonan syndrome. The diagnosis was suspected prenatally in two of them. Thirty-nine cases were identified in the literature. In the presented cases we show that suspicion of Noonan syndrome should arise when, after an increased nuchal translucency, ultrasound investigation in the second trimester shows a persistant nuchal fold (NF) or cystic hygroma in combination with at least one of the following features: hydrops fetalis, pleural effusion, cardiac anomalies, polyhydramnios or specific facial abnormalities.Conclusion Prenatal ultrasound findings in Noonan syndrome can be subtle and aspecific, but when specific characteristics are present additional targeted DNA analysis is indicated. Copyright (C) 2011 John Wiley & Sons, Ltd.

Background— This study determines the prevalence of Congenital Heart Defects (CHD), diagnosed prenatally or in infancy, and fetal and perinatal mortality associated with CHD in Europe. Methods and Results— Data were extracted from the European Surveillance of Congenital Anomalies central database for 29 population-based congenital anomaly registries in 16 European countries covering 3.3 million births during the period 2000 to 2005. CHD cases (n=26 598) comprised live births, fetal deaths from 20 weeks gestation, and terminations of pregnancy for fetal anomaly (TOPFA). The average total prevalence of CHD was 8.0 per 1000 births, and live birth prevalence was 7.2 per 1000 births, varying between countries. The total prevalence of nonchromosomal CHD was 7.0 per 1000 births, of which 3.6% were perinatal deaths, 20% prenatally diagnosed, and 5.6% TOPFA. Severe nonchromosomal CHD (ie, excluding ventricular septal defects, atrial septal defects, and pulmonary valve stenosis) occurred in 2.0 per 1000 births, of which 8.1% were perinatal deaths, 40% were prenatally diagnosed, and 14% were TOPFA (TOPFA range between countries 0% to 32%). Live-born CHD associated with Down syndrome occurred in 0.5 per 1000 births, with >4-fold variation between countries. Conclusion— Annually in the European Union, we estimate 36 000 children are live born with CHD and 3000 who are diagnosed with CHD die as a TOFPA, late fetal death, or early neonatal death. Investing in primary prevention and pathogenetic research is essential to reduce this burden, as well as continuing to improve cardiac services from in utero to adulthood.

Objectives To evaluate trends over time, indications, diagnoses, noncardiac defects and outcome of fetuses referred for tertiary level echocardiography. Methods Retrospective study of fetal echocardiograms performed between April 1999 and 2009. Results Of the 623 fetuses included, 301 (48%) had cardiac pathology. Congenital heart defects (CHDs) were found in 243/301 (81%), mostly in the severe spectrum. Of the fetuses with CHDs, 26% (63/243) had chromosomal anomalies. The chromosomally normal fetuses with CHDs had a mortality rate of 43% (77/180) and 23% (41/180) had extra-cardiac anomalies. The termination of pregnancy (TOP) rate for all cardiac pathology was 24.9% (75/301) and for CHDs 29.6% (72/243). The TOP rates for CHDs diagnosed before 19 and 24 weeks gestation were 61% (28/46) and 44% (68/155), respectively. An increase in referrals followed the introduction of a national screening program, (nuchal translucency (NT) and routine structural ultrasound screening). The main referral indication was an increased NT (> 95th percentile; 32% of cases). CHDs were found in 81/239 (34%) fetuses with an increased NT. Conclusions Referral indications for fetal echocardiography were appropriate (almost 50% had cardiac pathology). The mortality was high. Fetal outcome and TOP decisions correlated with CHD severity and presence of noncardiac defects. An increased NT is a strong marker for CHDs. Copyright c 2011 John Wiley & Sons, Ltd.

A retrospective study was performed to explore carrier testing among women who were possible or obligate carriers of the haemophilia gene. Knowledge of the possibility of carrier testing and use of carrier testing were studied separately. In our exploration we were guided by the diffusion theory and the Health Belief Model. Logistic regression analysis showed that four factors were statistically significant related to knowledge of carrier testing: information via mass media, a haemophilic relative in the nuclear family rather than in the extended family, medical severity of haemophilia, and information from the patients' organization. For those women acquainted with carrier testing two of the four factors just mentioned were significantly related to the utilization of carrier testing i.e. having a haemophilic relative in the nuclear family and the medical severity of the haemophilia. In addition the following factors were associated: attitude towards abortion because of haemophilia, educational level, and marital status. Notwithstanding the prominent function of the mass media and the patients' organization, the respondents themselves stated that relatives, especially parents and sisters, were the most important source of information on genetic counselling and carrier testing.

Objective To assess the impact of rapid aneuploidy detection (RAD) combined with fetal karyotyping versus karyotyping only on maternal anxiety and health-related quality of life. Methods Women choosing to undergo amniocentesis were selected into group 1, i.e. receiving a karyotype result only (n = 132) or to group 2, i.e. receiving both the result of RAD and karyotyping (n = 181). Results There were no systematic differences in time of RAD combined with karyotyping versus karyotyping only in terms of anxiety (P = 0.91), generic physical health (P = 0.76, P = 0.46), generic mental health (P = 0.52, P = 0.72), personal perceived control (P = 0.91) and stress (P = 0.13). RAD combined with karyotyping reduced anxiety and stress two weeks earlier compared to karyotyping only. Conclusion RAD as add-on to karyotyping reduces anxiety and stress in the short term but it does not influence overall anxiety, stress, personal perceived control, and generic mental and physical health when compared to a karyotype-only strategy. Copyright (C) 2010 John Wiley & Sons, Ltd.

Knowledge about the parental origin of new mutations and the occurrence of germline mosaicism is important for estimating recurrence risks in Duchenne (DMD) and Becker muscular dystrophy (BMD). However, there are problems in resolving these issues partly because not all mutations can as yet be directly detected, and additionally because genetic ratios are very sensitive to ascertainment bias. In the present study, therefore, analysis was restricted to currently detectable mutations (deletions and duplications) in particular types of families which tend to be rare. In order to obtain sufficient data we pooled results from 25 European centers. In mothers of affected patients who were the first in their family with a dystrophin gene deletion or duplication, the ratio between the paternal and the maternal origin of this new mutation was 32:49 (binomial test P = 0.075) for DMD. In five BMD families the ratio between paternal and maternal origin of new mutations was 3:2. Recurrence risk because of maternal germline mosaicism was studied in sisters or subsequent sibs of isolated cases with an apparently new detectable mutation. In 12 out of 59 (0.20; 95% CI 0.10-0.31) transmissions of the risk haplotype the DMD mutation was transmitted as well. No recurrences were found in nine BMD families.

BACKGROUND: Holoprosencephaly (HPE) is a developmental field defect of the brain that results in incomplete separation of the cerebral hemispheres that includes less severe phenotypes, such as arhinencephaly and single median rnaxillary central incisor. Information on the epidemiology of HPE is limited, both because few population-based studies have been reported, and because small Studies must observe a greater number of years in order to accumulate sufficient numbers of births for a reliable estimate. METHODS: We collected data from 2000 through 2004 from 24 of the 46 Birth Defects Registry Members of the International Clearinghouse for Birth Defects Surveillance and Research. This Study is based on more than 7 million births in various areas from North and South America, Europe, and Australia. RESULTS: A total of 963 HPE cases were registered, yielding an overall prevalence of 1.31 per 10,000 births. Because the estimate was heterogeneous, possible causes of variations among populations were analyzed: random variation, Under-reporting and over-reporting bias, variation in proportion of termination of pregnancies among all registered cases and real differences among populations. CONCLUSIONS: The data do not suggest large differences in total prevalence of HPE among the studied Populations that would be useful to generate etiological hypotheses.

Contains fulltext : 70871.pdf (Publisher’s version ) (Closed access) OBJECTIVE: To study the impact of terminations of pregnancy (TOP) on very preterm mortality in Europe. DESIGN: European prospective population-based cohort study. SETTING: Ten regions from nine European countries participating in the MOSAIC (Models of OrganiSing Access to Intensive Care for very preterm babies) study. These regions had different policies on screening for congenital anomalies (CAs) and on pregnancy termination. POPULATION OR SAMPLE: Births 22-31 weeks gestational age. METHODS: The analysis compares the proportion of TOP among very preterm births and assesses differences in mortality between the regions. MAIN OUTCOME MEASURES: Pregnancy outcomes (termination, antepartum death, intrapartum death and live birth) and reasons for termination, presence of CAs and causes of death for stillbirths and live births in 2003. RESULTS: Pregnancy terminations constituted between 1 and 21.5% of all very preterm births and between 4 and 53% of stillbirths. Most terminations were for CAs, although some were for obstetric indications (severe pre-eclampsia, growth restriction, premature rupture of membranes). TOP contributed substantially to overall fetal mortality rates in the two regions with late second-trimester screening. There was no clear association between policies governing screening and pregnancy termination and the proportion of CAs among stillbirths and live births, except in Poland, where neonatal deaths associated with CAs were more frequent, reflecting restrictive pregnancy termination policies. CONCLUSION: Proportions of TOP among very preterm births varied widely between European regions. Information on terminations should be reported when very preterm live births and stillbirths are compared internationally since national policies related to screening for CAs and the legality and timing of medical terminations differ.

Contains fulltext : 71381.pdf (Publisher’s version ) (Closed access) Chimerism occurs twice as often in the kidneys of women with lupus nephritis as in normal kidneys and may be involved in the pathogenesis of systemic lupus erythematosus. Pregnancy is considered the most important source of chimerism, but the exact relationship between pregnancy, the persistence of chimeric cells and the development of systemic lupus erythematosus has not been investigated. Renal biopsies and clinical data from patients in the First Dutch Lupus Nephritis Study were used. Chimeric cells were identified by in-situ hybridization of the Y chromosome. A questionnaire was used to obtain detailed reproductive data including pregnancy history and miscarriages. Chimerism was found in 12 of 26 (46%) renal biopsies. Of the 12 chimeric women, 5 reported a pregnancy; of 14 women who were not chimeric, 8 reported a pregnancy. Chimeric women who had been pregnant reported significantly more pregnancies than non-chimeric women who had been pregnant (P=0.04). The median age of the youngest child was higher in chimeric women (19 years) than in non-chimeric women (6 years). Despite the attention given to pregnancy histories with respect to chimerism, this study shows that in patients with systemic lupus erythematosus, a clear-cut relationship is not apparent. A considerable number of chimeric women did not report a pregnancy: in these women, other sources of chimerism must be considered. Our data support the theory that only certain subsets of chimeric cells persist into the maternal circulation after pregnancy.

Introducción: Las distrofias musculares de Duchenne y Becker son enfermedades recesivas ligadas al cromosoma X; la identificación de portadoras se puede hacer por métodos directos cuando se ha identificado la mutación, o por indirectos como el análisis de haplotipos. Objetivo: Se busca establecer mediante análisis de STRs y construcción de haplotipos el estado de portadora o no portadora en 37 familias con afectados por DMD/DMB. Metodología: Se estudiaron 174 personas mediante el análisis de 10 STRs intra y extragénicos del gen de la distrofina y la construcción de haplotipos para la identificación del ligado a la mutación. Resultados: Con la metodología mencionada se logró determinar el estado de portadora en 89.2% de las mujeres participantes, de las cuales 65.7% eran portadoras y 23.5% no portadoras. Conclusiones: El análisis indirecto mediante construcción de haplotipos permitió establecer el estado de portadora en una gran proporción de la población analizada de mujeres y permitió brindar un adecuado asesoramiento genético. Introduction: The muscular dystrophies of Duchenne and Becker are X-linked recessive neuromuscular disorders; the carrier testing protocols include mutation detection or linkage analysis.Objective: The aim of this investigation was to use the segregation analysis of STR loci to determine the carrier status in 37 families with DMD/DMB.Methods: From 37 families 174 individuals were studied through segregation of 10 intra and extragenic short tandem repeats (STR) in the members of the family.Results: The carrier status of 89.2% women of the tested group could be assigned by linkage analysis, 65.7% carriers and 23.5% non-carriersConclusions: Linkage analysis was proven to be a powerful tool for the carrier detection in DMD/BMD and should be taken into account in genetic counselling practice.

No abstract available

Recent work has demonstrated enhanced X monosomy in women with primary biliary cirrhosis (PBC) as well as two other female-predominant autoimmune diseases, systemic sclerosis and autoimmune thyroid disease. To further our understanding of these events, we have investigated the mechanisms of X chromosome loss and X chromosome inactivation (XCI) in 166 women with PBC and 226 rigorously age-matched healthy and liver disease controls. X chromosome analysis and determination of loss pattern was performed by quantitative fluorescent polymerase chain reaction (QF-PCR) with 4 X-linked short tandem repeats. Further definition of the XCI was based on analysis of methylation-sensitive restriction sites. Importantly, in PBC the X chromosome loss occurs not only more frequently but also in a preferential fashion. This observation supports our thesis that the enhanced X monosomy involves only one parentally derived chromosome and is not secondary to a constitutive non random pattern of XCI. In fact, in the presence of monosomy, the lost X chromosome is necessarily the inactive homologue. Conclusion: The finding that the X chromosome loss is preferential suggests the critical involvement of X chromosome gene products in the female predisposition to PBC and also emphasizes the need to determine the parental origin of the maintained chromosome to investigate the role of imprinting. (HEPATOLOGY 2007.)

Introduction: The phenotypic variability in Beckwith-Wiedemann Syndrome reflects the genetic heterogeneity of the mechanisms which default leads to deregulation of genes located at 11p15.5. Genotype-phenotype correlation studies demonstrated an association between omphalocele and CDKN1C/p57 mutations or hypermethylation. Paternal UPD11 (pUPD11) has been described only in mosaic condition with both uniparental and biparental cell lines and no association with omphalocele has been pointed out. Methods: Herein we present two cases in which a paternal segmental UPD11 was detected by molecular investigation of amniotic fluid cell cultures after the presence of apparently isolated omphalocele was revealed in the fetuses by ultrasound scan. Further studies were performed on additional autoptic feto-placental tissues to characterize the distribution of the uniparental cell line and unmask any biparental lineage in order to document more in detail the yet unreported association between omphalocele and pUPD11. Results: Results on the UPD distribution profile showed that the abdominal organs have a predominant uniparental constitution. This condition could mimic the effect of CDKN1C/p57 inactivation causing the omphalocele. Conclusions: New genotype-phenotype correlations emerge from the investigated cases suggesting to extend molecular analysis to all cases with fetal omphalocele in order to establish the incidence of pUPD11 not only in complete BWS but also in monosymptomatic/mild forms.

Background: Larsen syndrome is an autosomal dominant osteochondrodysplasia characterised by large-joint dislocations and craniofacial anomalies. Recently, Larsen syndrome was shown to be caused by missense mutations or small inframe deletions in FLNB, encoding the cytoskeletal protein filamin B. To further delineate the molecular causes of Larsen syndrome, 20 probands with Larsen syndrome together with their affected relatives were evaluated for mutations in FLNB and their phenotypes studied.Methods: Probands were screened for mutations in FLNB using a combination of denaturing high-performance liquid chromatography, direct sequencing and restriction endonuclease digestion. Clinical and radiographical features of the patients were evaluated.Results and discussion: The clinical signs most frequently associated with a FLNB mutation are the presence of supernumerary carpal and tarsal bones and short, broad, spatulate distal phalanges, particularly of the thumb. All individuals with Larsen syndrome-associated FLNB mutations are heterozygous for either missense or small inframe deletions. Three mutations are recurrent, with one mutation, 5071G -> A, observed in 6 of 20 subjects. The distribution of mutations within the FLNB gene is non-random, with clusters of mutations leading to substitutions in the actin-binding domain and filamin repeats 13-17 being the most common cause of Larsen syndrome. These findings collectively define autosomal dominant Larsen syndrome and demonstrate clustering of causative mutations in FLNB.

Item does not contain fulltext Array-based whole genome investigation or molecular karyotyping enables the genome-wide detection of submicroscopic imbalances. Proof-of-principle experiments have demonstrated that molecular karyotyping outperforms conventional karyotyping with regard to detection of chromosomal imbalances. This article identifies areas for which the technology seems matured and areas that require more investigations. Molecular karyotyping should be part of the genetic diagnostic work-up of patients with developmental disorders. For the implementation of the technique for other constitutional indications and in prenatal diagnosis, more research is appropriate. Also, the article aims to provide best practice guidelines for the application of array comparative genomic hybridisation to ensure both technical and clinical quality criteria that will optimise and standardise results and reports in diagnostic laboratories. In short, both the specificity and the sensitivity of the arrays should be evaluated in every laboratory offering the diagnostic test. Internal and external quality control programmes are urgently needed to evaluate and standardise the test results between laboratories.

Imbalances of 3p telomeric sequences cause 3p- and trisomy 3p syndrome, respectively, showing distinct, but also shared clinical features. No causative genes have been identified in trisomy 3p patients, but for the 3p- syndrome, there is growing evidence that monosomy for one or more of four genes at 3pter, CHL1, CNTN4, CRBN and MEGAP/srGAP3, may play a causative role. We describe here an analysis of a complex chromosome 3p aberration in a severely mentally retarded patient that revealed two adjacent segments with different copy number gains and a distal deletion. The deletion in this patient included the loci for CHL1, CNTN4, and CRBN, and narrowed the critical segment associated with the 3p- syndrome to 1.5 Mb, including the loci for CNTN4 and CRBN. We speculate that the deletion contributes more to this patient's phenotype than the gains that were observed. We suggest that 3p- syndrome associated features are primarily caused by loss of CNTN4 and CRBN, with loss of CHL1 probably having an additional detrimental effect on the cognitive functioning of the present patient. (c) 2006 Wiley-Liss, Inc.

Cytogenetic results of amniocentesis materials: incidence of abnormal karyotypes in the Turkish collaborative study: The experience on prenatal chromosome diagnosis of four Turkish centers participating in a collaborative study on 6041 genetic amniocentesis performed during a 4-8 years period were reviewed. 5887 (97.5%) patients had strong clinical indications for prenatal chromosome studies and 154 (2.5%) were referred because of maternal anxiety and a bad history of previous gestations. The main indication groups were: advanced maternal age (3197 cases), positive serum screening (2011 cases), ultrasound-identified anomaly (492 cases), previous fetus/child with chromosomal aberrations (103 cases), a history of a previous abnormal and / or mentally handicapped child (70 cases) and a parental chromosome rearrangement (14 cases). The average maternal age was 33.9 years and average gestational age was 18 weeks. A total of 179 affected fetuses were detected in this collaborative study (3%) of which 133 were unbalanced (74.3%). Among the 124 (69%) numerical aberrations, 102 (82.3%) were autosomal aneuploidies, 20 (16.1%) were gonosomal aneuploidies and 2 (1.6%) were poliploidies. Among the 55 (31%) structural aberrations, balanced translocation was the most common (63.6%) and I 1 cases of inversion, four cases of unbalanced translocation, two cases of marker chromosome and three cases of other abnormalities were found. The overall culture success rate was 99.7%. Pregnancy termination that is permitted by legal authorities was accepted by 94.7% (126/133) with parents at unbalanced cytogenetic result announcement.

Contains fulltext : 50606.pdf (Publisher’s version ) (Closed access) OBJECTIVE: For prenatal cytogenetic diagnosis, cell cultures should be maximally successful. When introducing a change in conditions, e.g. a new batch of medium, the growth potential of a culture is usually compared under both the new condition and the one already in use. Such a relative test is in principle subject to drift and may over time increasingly lead to rejection of new adequate conditions, c.q. good batches of medium. We therefore wanted to design an absolute test to assess the quality of a new condition for amniotic fluid (AF) in situ cell culturing. METHODS: We tested batches of medium under sub-optimal (stress) conditions, expecting that differences in growth potential would thereby be more readily observed. In our stress test, we diluted the culture medium to the extent of achieving a 50% growth reduction. Thresholds for rejecting a new condition were empirically determined, based on the acceptance of a less than 1% probability of false rejection of a good condition. RESULTS: Testing three cultures per patient for ten patients, i.e. 30 cultures in total, in a medium diluted to 30% of the original concentration, showed that a minimal number of 23 successful cultures and an average number of three or more colonies per culture appeared as thresholds meeting our rejection criteria. Testing five different media resulted in the rejection of one. Using the same stress test to evaluate the effect of culturing under decreased oxygen tension showed that 2.5 and 5% oxygen tension caused a larger colony size. CONCLUSION: We designed a sensitive absolute test to assess the quality of culturing conditions for cells to be used in prenatal diagnosis in general and in particular to test the growth potential of different batches of culture medium.

Sex tests based on amelogenin are part of various PCR multiplex reaction kits widely used for human gender identification and have important applications in forensic casework, prenatal diagnosis, DNA databasing and blood sample storage. The two most common sex tests based on amelogenin are represented by primer sets that delimit a 6-bp deletion on the X chromosome to produce X/Y fragments of 106/ 112 or 212/218 bp, respectively. Few cases of AMELY deletion, usually considered as polymorphisms, have been reported so far and a detailed characterization of the molecular alteration is still lacking. In this study, we describe a large interstitial deletion of the Y short arm encompassing the AMELY locus in two unrelated individuals. The first case was identified in an oligozoospermic, otherwise phenotypically normal, 32-yearold man during the screening for Y microdeletions performed on a sample of infertile males. The second one was found among amniotic liquid samples tested by quantitative fluorescence-polymerase chain reaction and cytogenetic analysis for prenatal diagnosis. The extent of the deletion, spanning approximately 2.5 Mb, was better characterised by pulsed-field gel electrophoresis,followed by fluorescence in situ hybridization and STS marker analysis.

Background Toxoplasmosis is an infectious disease caused by the parasitic protozoan Toxoplasma gondii. It is endemic worldwide and, depending on the geographic location, 15 to 85% of the human population are asymptomatically infected. Routine diagnosis is based on serology. The parasite has emerged as a major opportunistic pathogen for immunocompromised patients, in whom it can cause life-threatening disease. Moreover, when a pregnant woman develops a primary Toxoplasma gondii infection, the parasite may be transmitted to the fetus and cause serious damnage. For these two subpopulations, a rapid and accurate diagnosis is required to initiate treatment. Serological diagnosis of active infection is unreliable because reactivation is not always accompanied by changes in antibody levels, and the presence of IgM does not necessarily indicate recent infection. Application of quantitative PCR has evolved as a sensitive, specific, and rapid method for the detection of Toxoplasma gondii DNA in amniotic fluid, blood, tissue samples, and cerebrospinal fluid. Methods Two separate, real-time fluorescence PCR assays were designed and evaluated with clinical samples. The first, targeting the 35-fold repeated B1 gene, and a second, targeting a newly described multicopy genomic fragment of Toxoplasma gondii. Amplicons of different intragenic copies were analyzed for sequence heterogeneity. Results Comparative LightCycler experiments were conducted with a dilution series of Toxoplasma gondii genomic DNA, 5 reference strains, and 51 Toxoplasma gondii-positive amniotic fluid samples revealing a 10 to 100-fold higher sensitivity for the PCR assay targeting the newly described 529-bp repeat element of Toxoplasma gondii. Conclusion We have developed a quantitative LightCycler PCR protocol which offer rapid cycling with real-time, sequence-specific detection of amplicons. Results of quantitative PCR demonstrate that the 529-bp repeat element is repeated more than 300-fold in the genome of Toxoplasma gondii. Since individual intragenic copies of the target are conserved on sequence level, the high copy number leads to an ultimate level of analytical sensitivity in routine practice. This newly described 529-bp repeat element should be preferred to less repeated or more divergent target sequences in order to improve the sensitivity of PCR tests for the diagnosis of toxoplasmosis.

Objectives Objectives of this study are (1) to describe how to obtain the in-plane view of the inter-ventricular septum, (2) to assess its feasibility in a population of fetuses referred for fetal echocardiography, (3) to demonstrate its effectiveness in the characterization of VSD in the fetus. Methods The in-plane view of the inter-ventricular septum is conducted in a plane almost perpendicular to that of the long axis of the left ventricle, tilting the transducer towards the right ventricle, paying attention not to ‘enter’ the right ventricular chamber. Its feasibility has been assessed in 41 fetuses referred for fetal echocardiography, by recording the visualization/failure rates by fetal lie and acoustic window. The in-plane view of the inter-ventricular septum was then employed in healthy fetuses and diseased fetuses with VSDs. Results The success rates in obtaining the in-plane view of the inter-ventricular septum was dependent upon fetal lie; visualization rates were 100, 36 and 0% in case of posterior, lateral and anterior spine, respectively. When used in the anatomic characterization of VSDs, this view provided significant additional information. Conclusions The in-plane view of the inter-ventricular septum represents a new echocardiographic view that can be used to enhance the assessment of the inter-ventricular septum of the fetal heart. Its use should be considered whenever the presence of a VSD is suspected during fetal echocardiography, and in these cases it often provides additional information. Copyright © 2003 John Wiley & Sons, Ltd.

Contains fulltext : 185102.pdf (Publisher’s version ) (Closed access) Nonsyndromic X-linked mental retardation (MRX) is defined by an X-linked inheritance pattern of low IQ, problems with adaptive behavior, and the absence of additional specific clinical features. The 13 MRX genes identified to date account for less than one-fifth of all MRX, suggesting that numerous gene defects cause the disorder in other families. In a female patient with severe nonsyndromic mental retardation and a de novo balanced translocation t(X;7)(p11.3;q11.21), we have cloned the DNA fragment that contains the X-chromosomal and the autosomal breakpoint. In silico sequence analysis provided no indication of a causative role for the chromosome 7 breakpoint in mental retardation (MR), whereas, on the X chromosome, a zinc-finger gene, ZNF41, was found to be disrupted. Expression studies indicated that ZNF41 transcripts are absent in the patient cell line, suggesting that the mental disorder in this patient results from loss of functional ZNF41. Moreover, screening of a panel of patients with MRX led to the identification of two other ZNF41 mutations that were not found in healthy control individuals. A proline-to-leucine amino acid exchange is present in affected members of one family with MRX. A second family carries an intronic splice-site mutation that results in loss of specific ZNF41 splice variants. Wild-type ZNF41 contains a highly conserved transcriptional repressor domain that is linked to mechanisms of chromatin remodeling, a process that is defective in various other forms of MR. Our results suggest that ZNF41 is critical for cognitive development; further studies aim to elucidate the specific mechanisms by which ZNF41 alterations lead to MR.

Objective To describe the association between the Outcomes of pregnancies diagnosed with Klinefelter syndrome (KS) and the speciality of the health professional providing pre- and post-diagnostic counselling. Method Data were extracted from the case notes of the 111 cases of KS diagnosed prenatally between 1986 and 1997 in eight geographical regions in live European countries The data extracted included: outcome of pregnancy, maternal age, social class. parity, gestational age at diagnosis, year of diagnosis and specialities of the health professionals conducting pre- and post-diagnosis consultations. Results The overall termination rate was 44% (49/111: 95% confidence interval: 35 to 54). Using multivariable logistic regression analysis, the only significant predictor of continuation of the pregnancy was the specialities c the health professionals conducting post-diagnosis counselling: the affected pregnancy was more likely to continue when post-diagnosis counselling involved only a genetics specialist (relative risk: 2.42 (1.14 to 5.92)). Conclusion There is an association between whether or not a woman terminates a pregnancy affected by an unfamiliar fetal anomaly and the professional background of the health professional providing postdiagnostic counselling. The causal nature of this association remains to be determined. Copyright (C) 2002 John Wiley Sons, Ltd.

We studied the glucose-6-phosphatase (G6Pase) gene of 30 unrelated glycogen storage disease type Ia (GSD Ia) patients using single strand conformation, polymorphism (SSCP) prior to automated sequencing of exons revealing an aberrant SSCP pattern. In all patients we could identify mutations on both alleles of the G6Pase gene, indicating that this method is a reliable procedure. A total of 14 different mutations were identified. R83C (16/60), 158delC (12/60), Q347X (7/60), R170X (6/60) and Delta F337 (4/60) were found most frequently. Nine other mutations accounted for the other 15 mutant alleles. Two DNA-based prenatal diagnoses were performed successfully. At present, 56 mutations in the G6Pase gene have been reported in 300 unrelated GSD Ia patients and an overview of these mutations is presented. Evidence for a clear genotype-phenotype correlation could be established neither from our data nor from those in the literature. With increased knowledge about the genetic basis of GSD Ia and GSD Ib and the high detection rate of mutations, it is our opinion that the diagnoses GSD Ia and GSD Ib can usually be based on clinical and biochemical abnormalities combined with mutation analysis instead of enzyme assays in liver tissue obtained by biopsy. A newly developed flowchart for the diagnosis of GSD I is presented. Conclusion Increased knowledge of the genetic basis of glycogen storage disease type I provides a DNA-based diagnosis, prenatal DNA-based diagnosis in chorionic villus samples and carrier detection.

A cross-sectional study in a cohort of DNA proven carriers of Duchenne (DMD) and Becker (BMD) muscular dystrophy was undertaken with the following objectives: (1) to estimate the frequency of electrocardiographic (ECG) and echocardiographic abnormalities; (2) to establish the proportion of carriers with dilated cardiomyopathy and (3) to assess possible associations between dilated cardiomyopathy and genotype. One hundred and twenty nine DMD and BMD carriers, aged 18-60 years, were traced through the files of the central register kept at the department of Human Genetics in Leiden. Investigations included full medical history, physical examination, ECG and two-dimensional and M-mode echocardiographic examination. Forty-seven percent had ECG changes. Thirty-six percent (DMD 41%, BMD 27%) had at least one abnormality as is usually found in the male patients. Echocardiographic examination was abnormal in 36% (DMD 38%, BMD 34%). Dilated cardiomyopathy was found in seven DMD carriers (8%), and in none of BMD carriers. In addition, 18% had left ventricle dilatation (DMD 19%, BMD 16%). Only 38 % had a completely normal investigation of the heart. We found no association between genotype and cardiac manifestations. Our study underlines that cardiac involvement is part of the dystrophinopathies. Carriers should be told about the increased risk of this complication when asking genetic advice. It also implicates that a complete cardiological evaluation should be performed at least once in all carriers. If left ventricle dilatation or dilated cardiomyopathy is present a yearly follow up is needed, in order to start timely therapy. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.

Mosaicism for a balanced reciprocal translocation (BRTM) is rare. As far as we know only 26 cases of BRTM, demonstrated in lymphocyte cultures, have been described, five of which had an abnormal phenotype. Prenatally three confirmed cases with a normal phenotypic outcome have been described. Here we present three further cases of BRTM in lymphocyte cultures. The first was detected during a family study, the second after an abnormal karyotype in chorionic villus sampling, and the third because of a history of stillborn children, All three carriers have normal phenotypes, An inventory of the BRTM cases reported so far is made. Am. J. Med. Genet. 79:362-365, 1998, (C) 1998 Wiley-Liss, Inc.

In order to detect fetal nucleated red blood cells (NRBCs) in maternal blood, a protocol was developed which aimed at producing a reliable staining method for combined immunocytochemical and FISH analysis. The technique had to be suitable for eventual automated screening of slides. Chorionic villi washings, cord blood, and maternal blood samples were used for this study. After a density gradient separation and centrifugal cytology, slides were stained either with 3,3-diaminobenzidin (DAB), a marker for heme, or with antibodies against the gamma-chain of fetal hemoglobin (HbF). FISH analysis for both X- and Y-chromosomes was performed on the same slides. Cytocentrifugation provided a controlled cell density on the slides with good cell morphology, Both the DAB and HbF staining were suitable for manual screening of large numbers of slides. The HbF staining, although supposed to be more specific for fetal NRBCs, appeared to be more sensitive to minor changes in preparation. We were eventually able to combine HbF staining with FISH analysis, and produced a detection efficiency of > 85% for both X- and Y-chromosome signals. This preparation protocol simplifies the detection of NRBCs in maternal blood. Immunocytochemical staining and FISH analysis can be performed on the same cell with good image contrast, thus facilitating both manual and automated image analysis. This will facilitate the use of this approach for prenatal diagnosis. (C) 1998 Wiley-Liss, Inc.

A (semi-) randomized controlled study with long-term follow-up was conducted to compare the effects of transabdominal chorionic villus sampling and early amniocentesis on fetal mortality and child morbidity. Women requesting early prenatal diagnosis for advanced maternal age were allocated to early amniocentesis or transabdominal chorionic villus sampling either by randomization or, if they declined randomization, by their own choice. Of the 212 women who entered the study, 117 were randomized, 70 chose early amniocentesis and 25 chose transabdominal chorionic villus sampling. Overall, 130 women underwent early amniocentesis and 74 underwent transabdominal chorionic villus sampling at a median gestation of 12 weeks. Two women were excluded because of fetal death before the procedure. Mosaic karyotypes were found in 5.4 per cent of the early amniocenteses and in none of the chorionic villus samples. All unintended fetal losses occurred after early amniocentesis with a frequency of 6.2 per cent (95 per cent confidence interval: 2.7 per cent to 11.8 per cent). Talipes equinovarus was only observed after early amniocentesis with a frequency of 3.1 per cent (95 per cent confidence interval: 0.8 per cent to 7.7 per cent). We conclude that chorionic villus sampling remains the method of choice if prenatal diagnosis is needed in the first trimester of pregnancy. (C) 1998 John Wiley & Sons, Ltd.

Two groups of pregnant women were questioned regarding their opinions on serum screening for Down's syndrome in the first trimester of pregnancy. One group comprised 83 women attending our antenatal clinic who were questioned at the time of the existing second-trimester screening test. Seventy-six per cent of those who participated in the second-trimester screening programme would have preferred the test to have been in the first trimester, mainly because of the easier termination of pregnancy and/or the earlier reassurance provided. The remaining 24 per cent could see no advantage in the earlier time frame. Of the 49 women who had declined second-trimester screening, only two would have participated in screening had it been in the first trimester. The other group comprised those women attending our antenatal diagnosis clinic who were considering chorionic villus sampling (CVS). Forty-four per cent of these women would have allowed serum screening in the first trimester to influence their decision as to whether to undergo definitive prenatal diagnostic testing. In general, those women who made use of second-trimester serum screening would also do so in the first trimester. Those who declined the existing screening programme would also decline first-trimester screening. Many women currently deciding to undergo CVS would allow a first-trimester screening test to influence their decision. (C) 1997 by John Wiley & Sons, Ltd.

The aim of this article is to examine the performance of screening for fetal Down syndrome (DS) in the context of demographic variation in time and place, using population and fertility data for several European countries. Two screening approaches are distinguished: one on the basis of maternal serum screening with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) in combination with maternal age, and one on the basis of maternal age only. Screening performance, as measured by detection and false-positive ratios, is shown to be the result of the screening approach chosen and of the demographic characteristics of the population under consideration. A proper distinction between these two determinants of DS screening performance should be made, in order to distinguish between an improvement in screening performance that is brought about by a new screening approach and an improvement that is brought about by demographic change. We recommend that measures of DS screening performance be standardized for demographic variation. The methodology and demographic data presented in this article can be used for this purpose. (C) 1997 by John Wiley & Sons, Ltd.

The aim of this article is to examine the performance of screening for fetal Down syndrome (DS) in the context of demographic variation in time and place, using population and fertility data for several European countries. Two screening approaches are distinguished: one on the basis of maternal serum screening with human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP) in combination with maternal age, and one on the basis of maternal age only. Screening performance, as measured by detection and false-positive ratios, is shown to be the result of the screening approach chosen and of the demographic characteristics of the population under consideration. A proper distinction between these two determinants of DS screening performance should be made, in order to distinguish between an improvement in screening performance that is brought about by a new screening approach and an improvement that is brought about by demographic change. We recommend that measures of DS screening performance be standardized for demographic variation. The methodology and demographic data presented in this article can be used for this purpose. (C) 1997 by John Wiley & Sons, Ltd.

Objectives To examine trends in the prevalence of congenital heart defects (CHDs) in Europe and to compare these trends with the recent decrease in the prevalence of CHDs in Canada (Quebec) that was attributed to the policy of mandatory folic acid fortification.Study design We used data for the period 1990-2007 for 47 508 cases of CHD not associated with a chromosomal anomaly from 29 population-based European Surveillance of Congenital Anomalies registries in 16 countries covering 7.3 million births. We estimated trends for all CHDs combined and separately for 3 severity groups using random-effects Poisson regression models with splines.Results We found that the total prevalence of CHDs increased during the 1990s and the early 2000s until 2004 and decreased thereafter. We found essentially no trend in total prevalence of the most severe group (group I), whereas the prevalence of severity group II increased until about 2000 and decreased thereafter. Trends for severity group III (the most prevalent group) paralleled those for all CHDs combined.Conclusions The prevalence of CHDs decreased in recent years in Europe in the absence of a policy for mandatory folic acid fortification. One possible explanation for this decrease may be an as-yet-undocumented increase in folic acid intake of women in Europe following recommendations for folic acid supplementation and/or voluntary fortification. However, alternative hypotheses, including reductions in risk factors of CHDs (eg, maternal smoking) and improved management of maternal chronic health conditions (eg, diabetes), must also be considered for explaining the observed decrease in the prevalence of CHDs in Europe or elsewhere. (J Pediatr 2013;162:108-13).

The fragile X syndrome is associated with an expanding CGG repeat in the 5' untranslated region of the first exon of the FMR1 gene. Subsequent methylation of the promoter region inhibits expression of the FMR1 gene. In two clinically normal brothers large, expanded CGG repeats and cytogenetically visible fragile sites were found. The FMR1 promoter was unmethylated and both RNA and protein could be detected. This indicates that inactivation of the FMR1 gene and not repeat expansion itself results in the fragile X phenotype. We conclude that repeat expansion does not necessarily induce methylation and that methylation is no absolute requirement for the induction of fragile sites.

A fetal goitre is a potentially dangerous phenomenon because of mechanical obstruction and possible fetal thyroid function disorders. In this report we describe a patient with Graves' disease diagnosed in early pregnancy and treated with propylthiouracil, which resulted in a large fetal goitre and fetal hypothyroidism. The diagnostic problems are discussed and we focus on the need for fetal thyroid hormone serum evaluation. The only reliable way to obtain information about the fetal thyroid status is percutaneous fetal umbilical cord blood sampling, since amniotic fluid levels do not properly represent the fetal thyroid function. Fetal hypothyroidism can thus be diagnosed in utero and treated with intra-amniotic injections of thyroxine. The recommended dose and frequency of injections are only based on a few case reports and for that reason we performed a second fetal blood sampling 1 week later to evaluate our therapy. Weekly intra-amniotic injections of 250 mu g of thyroxine seem to be sufficient to reduce a fetal goitre and give a normal thyroid hormone level.