Prevalence and risk of Down syndrome in monozygotic and dizygotic multiple pregnancies in Europe: implications for prenatal screening.

OBJECTIVE: To determine risk of Down syndrome (DS) in multiple relative to singleton pregnancies, and compare prenatal diagnosis rates and pregnancy outcome. DESIGN: Population-based prevalence study based on EUROCAT congenital anomaly registries. SETTING: Eight European countries. POPULATION: 14.8 million births 1990-2009; 2.89% multiple births. METHODS: DS cases included livebirths, fetal deaths from 20 weeks, and terminations of pregnancy for fetal anomaly (TOPFA). Zygosity is inferred from like/unlike sex for birth denominators, and from concordance for DS cases. MAIN OUTCOME MEASURES: Relative risk (RR) of DS per fetus/baby from multiple versus singleton pregnancies and per pregnancy in monozygotic/dizygotic versus singleton pregnancies. Proportion of prenatally diagnosed and pregnancy outcome. STATISTICAL ANALYSIS: Poisson and logistic regression stratified for maternal age, country and time. RESULTS: Overall, the adjusted (adj) RR of DS for fetus/babies from multiple versus singleton pregnancies was 0.58 (95% CI 0.53-0.62), similar for all maternal ages except for mothers over 44, for whom it was considerably lower. In 8.7% of twin pairs affected by DS, both co-twins were diagnosed with the condition. The adjRR of DS for monozygotic versus singleton pregnancies was 0.34 (95% CI 0.25-0.44) and for dizygotic versus singleton pregnancies 1.34 (95% CI 1.23-1.46). DS fetuses from multiple births were less likely to be prenatally diagnosed than singletons (adjOR 0.62 [95% CI 0.50-0.78]) and following diagnosis less likely to be TOPFA (adjOR 0.40 [95% CI 0.27-0.59]). CONCLUSIONS: The risk of DS per fetus/baby is lower in multiple than singleton pregnancies. These estimates can be used for genetic counselling and prenatal screening.

Trends in the prevalence, risk and pregnancy outcome of multiple births with congenital anomaly: a registry-based study in 14 European countries 1984-2007.

OBJECTIVE: To assess the public health consequences of the rise in multiple births with respect to congenital anomalies. DESIGN: Descriptive epidemiological analysis of data from population-based congenital anomaly registries. SETTING: Fourteen European countries. POPULATION: A total of 5.4 million births 1984-2007, of which 3% were multiple births. METHODS: Cases of congenital anomaly included live births, fetal deaths from 20 weeks of gestation and terminations of pregnancy for fetal anomaly. MAIN OUTCOME MEASURES: Prevalence rates per 10,000 births and relative risk of congenital anomaly in multiple versus singleton births (1984-2007); proportion prenatally diagnosed, proportion by pregnancy outcome (2000-07). Proportion of pairs where both co-twins were cases. RESULTS: Prevalence of congenital anomalies from multiple births increased from 5.9 (1984-87) to 10.7 per 10,000 births (2004-07). Relative risk of nonchromosomal anomaly in multiple births was 1.35 (95% CI 1.31-1.39), increasing over time, and of chromosomal anomalies was 0.72 (95% CI 0.65-0.80), decreasing over time. In 11.4% of affected twin pairs both babies had congenital anomalies (2000-07). The prenatal diagnosis rate was similar for multiple and singleton pregnancies. Cases from multiple pregnancies were less likely to be terminations of pregnancy for fetal anomaly, odds ratio 0.41 (95% CI 0.35-0.48) and more likely to be stillbirths and neonatal deaths. CONCLUSIONS: The increase in babies who are both from a multiple pregnancy and affected by a congenital anomaly has implications for prenatal and postnatal service provision. The contribution of assisted reproductive technologies to the increase in risk needs further research. The deficit of chromosomal anomalies among multiple births has relevance for prenatal risk counselling.

Anorectal malformations and pregnancy-related disorders: a registry-based case-control study in 17 European regions.

OBJECTIVE: To identify pregnancy-related risk factors for different manifestations of congenital anorectal malformations (ARMs). DESIGN: A population-based case-control study. SETTING: Seventeen EUROCAT (European Surveillance of Congenital Anomalies) registries, 1980-2008. POPULATION: The study population consisted of 1417 cases with ARM, including 648 cases of isolated ARM, 601 cases of ARM with additional congenital anomalies, and 168 cases of ARM-VACTERL (vertebral, anal, cardiac, tracheo-esophageal, renal, and limb defects), along with 13 371 controls with recognised syndromes or chromosomal abnormalities. METHODS: Multiple logistic regression analyses were used to calculate adjusted odds ratios (ORs) for potential risk factors for ARM, such as fertility treatment, multiple pregnancy, primiparity, maternal illnesses during pregnancy, and pregnancy-related complications. MAIN OUTCOME MEASURES: Adjusted ORs for pregnancy-related risk factors for ARM. RESULTS: The ARM cases were more likely to be firstborn than the controls (OR 1.6, 95% CI 1.4-1.8). Fertility treatment and being one of twins or triplets seemed to increase the risk of ARM in cases with additional congenital anomalies or VACTERL (ORs ranging from 1.6 to 2.5). Maternal fever during pregnancy and pre-eclampsia were only associated with ARM when additional congenital anomalies were present (OR 3.9, 95% CI 1.3-11.6; OR 3.4, 95% CI 1.6-7.1, respectively), whereas maternal epilepsy during pregnancy resulted in a five-fold elevated risk of all manifestations of ARM (OR 5.1, 95% CI 1.7-15.6). CONCLUSIONS: This large European study identified maternal epilepsy, fertility treatment, multiple pregnancy, primiparity, pre-eclampsia, and maternal fever during pregnancy as potential risk factors primarily for complex manifestations of ARM with additional congenital anomalies and VACTERL.

Novel missense mutations in the ubiquitination-related gene UBE2A cause a recognizable X-linked mental retardation syndrome.

Recently, a truncating mutation of the UBE2A gene has been observed in a family with X-linked mental retardation (XLMR) (1). The three affected males had similar phenotypes, including seizures, obesity, marked hirsutism and a characteristic facial appearance. Here, we report on two families with a total of seven patients and a clinically very similar syndromic form of XLMR. Linkage analysis was performed in the larger of these families, and screening several positional candidate genes revealed a G23R missense mutation in the UBE2A gene. Subsequent UBE2A screening of a phenotypically similar second family revealed another missense mutation, R11Q, again affecting an evolutionarily conserved amino acid close to the N-terminus of the protein. SIFT and PolyPhen analyses suggest that both mutations are pathogenic, which is supported by their absence in 168 healthy controls. Thus, both missense and truncating mutations can give rise to a specific, syndromic form of XLMR which is identifiable in a clinical setting.

A novel nonsense mutation in CUL4B gene in three brothers with X-linked mental retardation syndrome.

Cabezas syndrome (MIM 300354) is a recently identified syndromic form of X-linked mental retardation (XLMR) caused by mutations in the CUL4B gene. In total, nine XLMR families carrying mutations in the CUL4B gene have been described to date. Here, we present a detailed clinical phenotype of three affected brothers of Polish descent. Based on the symptoms, we made a clinical diagnosis of Cabezas syndrome, which was subsequently confirmed by identification of a novel nonsense mutation (c.2107A-->T, p.703K-->X) in exon 18 of the CUL4B gene. The mutation was inherited from an asymptomatic mother and was present in all three affected brothers. The patients presented with typical features of Cabezas syndrome, such as severe mental retardation, speech impairment, hyperactivity, seizures, intention tremor, inguinal hernia, small feet, and craniofacial dysmorphism. In addition to previously described symptoms, syndactyly of the second and third toes and skin manifestations (hyperhydrosis and keratosis pilaris) were present in our cases. Our report provides further support that Cabezas syndrome is a recognizable syndromic form of XLMR. We conclude that the CUL4B gene should be screened in males with severe speech impairment and primary intention tremor, especially if characteristic facial dysmorphism is also present.

The highly conserved NANOS2 protein: testis-specific expression and significance for the human male reproduction.

The highly conserved Nanos gene was found to encode a translational repressor necessary for germ-cell development in lower organisms. The mammalian homologue, Nanos2, was recently found to be expressed in the mouse germ cells. Since its disruption caused infertility exclusively in males, we sought to study the significance of this gene in human male reproduction. Here, we describe for the first time the expression pattern of the NANOS2 gene in human tissues and show that it is testis specific. We found that NANOS2 protein is present in prenatal germ cells and at later stages in spermatogenesis. To elucidate the role of NANOS2 in human germ-line development, we screened this gene for mutations in 214 males with isolated sterility and spermatogenic abnormalities. We identified two heterozygous variants, each in a different oligospermic patient, the second allele being the wild-type. The influence of the first variant, a missense mutation H68Q on the sterility phenotype, was not obvious since it was accompanied by a microdeletion within the AZF region of the Y chromosome. The second variant contained a silent mutation, H109H. Although both mutations were situated within the most conserved RNA-binding domain and were absent in 400 fertile males, it is not obvious that they cause male infertility.

A novel GJA1 missense mutation in a Polish child with oculodentodigital dysplasia.

Oculodentodigital dysplasia (ODDD) (OMIM #164200) is a rare congenital, autosomal dominant disorder comprising craniofacial, ocular, dental, and digital anomalies. The syndrome is caused by GJA1 mutations. The clinical phenotype of ODDD involves a characteristic dysmorphic facies, ocular findings (microphthalmia, microcornea, glaucoma), syndactyly type III of the hands, phalangeal abnormalities, diffuse skeletal dysplasia, enamel dysplasia, and hypotrichosis. In a Polish child with the clinical symptoms typical of ODDD, we demonstrated a novel missense mutation c.C31A resulting in p.L11F substitution. Our report provides evidence on the importance of this highly conserved amino acid residue for the proper functioning of GJA1 protein.

A new sporadic case of early-onset Loeys-Dietz syndrome due to the recurrent mutation p.R528C in the TGFBR2 gene substantiates interindividual clinical variability.

We report on a 2-year-old Polish girl with typical manifestations of Loeys-Dietz syndrome (LDS), a rare genetic condition belonging to the group of Marfan-related disorders. The characteristic LDS symptoms observed in the girl included craniofacial dysmorphism (craniosynostosis, cleft palate, hypertelorism), arachnodactyly, camptodactyly, scoliosis, joint laxity, talipes equinovarus, translucent and hyperelastic skin, and umbilical hernia. Mild dilatation of the ascending aorta and tortuous course of the left internal carotid artery were recognized during her second year of life. Molecular genetic testing revealed a heterozygous missense mutation (c.1582C>T, p.R528C) in the transforming growth factor beta receptor II gene (TGFBR2). This mutation has been previously associated with LDS in 5 unrelated cases, and was never reported in patients with other Marfan-related disorders. Comparison of the phenotypes of our patient and these 5 individuals with c.1582C>T showed that only the hallmark triad of the syndrome - consisting of hypertelorism, aortic root dilatation/aneurysm, and cleft palate or bifid uvula - was present in all 6 cases. Interestingly, none of the 5 individuals who underwent psychological evaluation showed developmental delay. The pattern of all other LDS features showed interindividual variability. Our data support the recently reported observation that symptoms of LDS can develop at a very young age, making early diagnosis and management essential for these patients. This is the first report on a Polish infant with typical LDS symptoms caused by a TGFBR2 mutation.

Collagens, the basic proteins of the human body.

Collagens are structural elements of many tissues in the human body. The family of collagens can be divided into fibrillar and non-fibrillar collagens. The criterion of the classification is the structure of these proteins. Mutations in the genes encoding collagens cause a variety of human diseases that include osteogenesis imperfecta, some forms of osteoporosis, chondrodysplasias, some types of Ehlers-Danlos syndrome, arterial and intracranial aneurysms, epidermolysis bullosa and the renal disease known as Alport syndrome. The detection of mutations is important both scientifically and clinically. Defining the molecular defects underlying a disorder helps in the understanding of not only the properties of the mutated protein but also the function of the normal protein. Even though many mutations in the genes encoding collagens have been described, the pathogenic consequences of some of the mutations are not fully understood. The important rationale for mutation detection is the clinical use of molecular diagnostics in genetic counselling and differential diagnosis.

A familial X/Y translocation: cytogenetic and molecular study.

In this study we describe a 3-generation family carrying a (X;Y)(p22.3;q11.2) translocation in seven individuals of both sexes. Molecular analysis of the aberrant (X;Y)(p22.3;q11.2) chromosome was performed by FISH using X and Y-specific painting probes and also PCR amplification of the Y-specific sequences. Using these approaches it was demonstrated that the translocation resulted in a deletion of both X and Y pseudoautosomal regions. Moreover, using RBG banding it was shown that in all females the X-derivative chromosome was inactive in over 90% of mitoses. From the preliminary results obtained in this study we assumed that in this particular family the observed phenotype of the patients was caused by a deletion of the cluster of pseudoaotosomal genes responsible for the stature. More proximal loci, like STS or MRX49, were probably not deleted, since neither ichtyosis nor mental retardation was observed in this family.

Idiopathic infertility in married couples in the light of cytogenetic analysis and sperm penetration assay.

We have selected 47 couples with unexplained infertility in order to analyse a possible link between sperm dysfunction studied in males in in vitro conditions and karyotype analysis of somatic cells. In order to identify so called "idiopathically infertile" couples we had to exclude any change in reproductive organs in both partners or in spermiogram which would qualify any of spouses into known category of infertility. We have revealed chromosome aberrations (translocations and marker chromosomes) in 19% of infertile males and in 6% of infertile females. Idiopathically infertile males had an overall decreased ability of sperm function (measured by proportion of penetrated hamster oocytes by human sperm) in comparison to fertile controls, however, still well placed within physiological range of values. Only sperm from a patient with identified translocation was clearly below the normal level of penetration (20% of penetrated oocytes), however, also the patients with revealed chromosome variant polymorphisms presented statistically lower values of penetration in comparison to fertile controls (39% vs 57%, p<0.05). On the contrary, patients with marker chromosomes did not exhibit affected sperm function. It can be speculated that only particular chromosome aberration in group of idiopathically infertile males may affect sperm functional capability (measured in vitro), however, the intragonadal genetic analysis has to be recommended in order to confirm such a causative link.

DNA damage induced by lithotripter generated shock waves: short report.

The side effects of shock waves on biological tissues have been intensively investigated in past years. In contrast to the morphological studies, only a little information exists up to now about molecular effects of shock waves at the DNA level. To study the shock wave effects on DNA in water solution, 100, 500, 1,000, 1,500 wave shocks, generated with a experimental lithotripter, were applied at 18 kV and 20 kV, corresponding to the positive pressure peaks of 16 and 30 MPa and negative ones of 5 and 9 MPa. The DNA damage was evaluated in two "submarine" electrophoresis approaches. In the first - standard DNA electrophoresis - no DNA damage was detected, confirming previously described results. In the second electrophoresis, performed under changed conditions, sever double strand DNA damage was found. Our results strongly suggest that shock waves applied at the therapeutical level of energy may generate the double strand DNA damage.

[Chondrosarcoma of the small pelvis imitating an ovarian tumor]. / Chrzestniakomiesak miednicy mniejszej imitujacy guz jajnika.

The authors present diagnostic-therapeutic record concerning chondrosarcoma-tumor in 41-year-old women operated on ovary-tumor. They point out the rareness of chondrosarcoma within pelvis, the diagnostic and therapeutic difficulties and relapses into illness after radical remove of tumour without pelvis bones resection.

[Importance of cytogenetic analysis in patients with azoospermia or severe oligozoospermia undergoing in vitro fertilization]. / Znaczenie badan cytogenetycznych u pacjentów z azoospermia lub ciezka postacia oligozoospermii, korzystajacych z zaplodnienia in vitro.

The karyotypic analysis was performed to assess the importance of genetic factor in male infertility. For that purpose, chromosomal analysis in blood lymphocytes was performed in 28 males, candidates for ICSI with azoospermia or severe oligozoospermia and in their spouses. Although chromosomal aberrations were identified in as many as 11 couples, (in 6 couples aberrations were identified in male, in 4 other couples in female partner, whereas in 1 one couple they were detected in both partners) their risk for potential offspring is unequal. Balanced autosomal aberrations detected in two males (7%) constitute a high risk since they can cause not only infertility but also severe somatic abnormalities if transferred as the unbalanced ones to the next generation. The remaining 9 chromosomal aberrations identified in this study were present in mosaic additional cell lines with low representation. In 8 of them sex chromosomes and in 1 an autosom were involved. Although these mosaic chromosomal aberrations can lower efficiency of in vitro fertilisation, the probability that they can be transferred to the next generation causing somatic abnormalities is not high. This study indicates that in case of azoospermia or severe oligozoospermia, the karyotypic analysis should be performed in both partners prior to in vitro fertilisation.

[Genetically determined retinoblastoma]. / Genetyczne uwarunkowania siatkówczaka.

The modern view for the mechanisms of retinoblastoma origination, based on the tumor suppressor genes theory, has been described in this work. The structure and function of the retinoblastoma gene and its protein product, with reference to the cell cycle, has been presented. On the ground of this data, possibilities of genetic molecular diagnostics and principles of competent genetic counselling have been described.

[Marshall syndrome--case report]. / Zespól Marshalla--opis przypadku.

A girl, 15, with Marshall syndrome, was hospitalized for retinal tear and detachment of the left eye. The results of ophthalmological examination and applied eye surgery have been described. The authors confirm the essential phenotypical overlap of Marshall and Stickler syndromes. This suggest that they are caused by variable expression of a differently mutated gene, probably the type II procollagen gene (COL2A1), known to play a part in the etiology of Stickler syndrome. This justifies the usage, by some authors, of the common name of Marshall-Stickler syndrome.