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Biomedical subjects

M C Addor

Publications and source records attributed to M C Addor.

At least 19 recordsLinked to original sources

Trends and geographic inequalities in the prevalence of Down syndrome in Europe, 1980-1999.

BACKGROUND: EUROCAT is a network of population-based registries for the epidemiologic surveillance of congenital anomalies covering approximately one quarter of births in the European Union. Down syndrome constitutes approximately 8% of cases of registered congenital anomaly in Europe, with over 7000 affected pregnancies in the 15 current member states of the European Union each year. In this paper, we aim to examine trends in the live birth prevalence of Down syndrome in Europe in the light of trends in maternal age and in prenatal diagnosis. METHODS: Descriptive analysis of data from 24 EUROCAT registries, covering 8.3 million births 1980-99. Cases include live births, stillbirths and terminations of pregnancy following prenatal diagnosis. RESULTS: Since 1980, the proportion of births to mothers of 35 years of age and over has risen quite dramatically from 8 to 14% for the European Union as a whole, with steeper rises in some regions. By 1995-1999, the proportion of "older" mothers varied between regions from 10% to 25%, and the total prevalence (including terminations of pregnancy) of Down syndrome varied from 1 to 3 per 1000 births. Some European regions have shown a more than twofold increase in total prevalence of Down syndrome since 1980. The proportion of cases of Down syndrome which were prenatally diagnosed followed by termination of pregnancy in 1995-1999 varied from 0% in the three regions of Ireland and Malta where termination of pregnancy is illegal, to less than 50% in 14 further regions, to 77% in Paris. The extent to which terminations of pregnancy were concen trated among older mothers varied between regions. The live birth prevalence has since 1980 increasingly diverged from the rising total prevalence, in some areas remaining approximately stable, in others decreasing over time. CONCLUSION: The rise in average maternal age in Europe has brought with it an increase in the number of pregnancies affected by Down syndrome. The widespread practice of prenatal screening and termination of pregnancy has in most of the regions covered by EUROCAT counteracted the effect of maternal age in its effect on live birth prevalence. Under the joint influences of maternal age and prenatal screening the pattern of geographic inequalities in Down syndrome live birth prevalence in Europe has also been changed.

Adult↗

Partial trisomy 20q in a newborn with dextrocardia.

A female newborn is reported with dextrocardia and a partial trisomy 20q, derived from a t(2;20) paternal translocation. The most discriminating findings of the condition include brachycephaly, bulging forehead, deep set eyes, short nose, large ears, dimpled chin, short neck and a heart defect. Previously reported patients with this rare chromosomal anomaly are reviewed.

Chromosomes, Human, Pair 20↗

Screening for foetal malformations: performance of routine ultrasonography in the population of the Swiss Canton of Vaud.

OBJECTIVE: To determine the sensitivity of ultrasonography in screening for foetal malformations in the pregnant women of the Swiss Canton of Vaud. STUDY DESIGN: Retrospective study over a period of five years. METHOD: We focused our study on 512 major or minor clinically relevant malformations detectable by ultrasonography. We analysed the global sensitivity of the screening and compared the performance of the tertiary centre with that of practitioners working in private practice or regional hospitals. RESULTS: Among the 512 malformations, 181 (35%) involved the renal and urinary tract system, 137 (27%) the heart, 71 (14%) the central nervous system, 50 (10%) the digestive system, 42 (8%) the face and 31 (6%) the limbs. Global sensitivity was 54.5%. The lowest detection rate was observed for cardiac anomalies, with only 23% correct diagnoses. The tertiary centre achieved a 75% detection rate in its outpatient clinic and 83% in referred patients. Outside the referral centre, the diagnostic rate attained 47%. CONCLUSIONS: Routine foetal examination by ultrasonography in a low-risk population can detect foetal structural abnormalities. Apart from the diagnosis of cardiac abnormalities, the results in the Canton of Vaud are satisfactory and justify routine screening for malformations in a low-risk population. A prerequisite is continuing improvement in the skills of ultrasonographers through medical education.

Central Nervous System↗

A characteristic EEG pattern in 4p-syndrome: case report and review of the literature.

UNLABELLED: Deletions on the short arm of chromosome 4 cause Wolf-Hirschhorn syndrome (WHS) and Pitt-Rogers-Danks syndrome (PRDS). WHS is associated with severe growth and mental retardation, microcephaly, a characteristic facies and congenital malformations. The PRDS phenotype is similar to WHS but generally less severe. Seizures occur in the majority of WHS and PRDS patients. Sgrò et al. [17] described a stereotypic electroclinical pattern in four unrelated WHS patients, consisting of intermittent bursts of 2-3 Hz high voltage slow waves with spike wave activity in the parietal areas during drowsiness and sleep associated with myoclonic jerks. We report a patient with PRDS and the typical EEG pattern and review 14 WHS patients with similar EEG findings reported in the literature. CONCLUSION: Awareness and recognition of the characteristic electroclinical findings in Wolf-Hirschhorn syndrome and Pitt-Rogers-Danks syndrome might help in the early diagnosis of such patients.

Abnormalities, Multiple↗

Fatal outcome in a female monozygotic twin with X-linked hypohydrotic ectodermal dysplasia (XLHED) due to a de novo t(X;9) translocation with probable disruption of the EDA gene.

UNLABELLED: Ectodermal dysplasias are a group of congenital disorders with defective development of the epidermis and its appendages. X-linked hypohydrotic ectodermal dysplasia (XLHED; OMIM 305100) is the most common form of ectodermal dysplasia. We report on two monozygotic twin girls with XLHED due to a t(X;9) translocation causing a disruption of the EDA gene and non random inactivation of the normal X chromosome. One of the girls died unexpectedly at 2.5 years of age. Autopsy revealed that lack of normal tracheobronchial secretions leading to complete tracheal obstruction by mucous debris was the probable cause of death. CONCLUSION: Morbidity and mortality of ectodermal dysplasias in infancy and early childhood can be significant. Early diagnosis by paediatricians is important and complications should be anticipated.

Child, Preschool↗

Further delineation of the facial 13q14 deletion syndrome in 13 retinoblastoma patients.

Thirteen years ago, Motegi and colleagues (J Med Genet 1987;24:696-697) summarized the specific facial phenotype of six Japanese retinoblastoma patients with interstitial 13q14 deletions. Among a series of 228 propositi with retinoblastoma referred to the Lausanne Retinoblastoma Clinic for treatment and genetic counseling between 1986 and 1997, 13 (5.7%) were diagnosed with a cytogenetic de-novo 13q14 deletion. We confirm the presence of the reported facial phenotype in our population of Caucasian patients and describe additional clinical traits, thus extending the facial phenotype associated with the 13q14 deletion. Del(13q14) comprises, among others, cranial anomalies, frontal bossing, deeply grooved and long philtrum, depressed and broad nasal bridge, bulbous tip of the nose, thick lower lip, thin upper lip, broad cheeks, and large ears and lobules. Recognition of this particular facial appearance was instrumental in the genetic diagnosis of 13q deletions and in the presymptomatic diagnosis of retinoblastoma in a significant number of our cases. Identification of this phenotype in a retinoblastoma patient allows for efficient diagnosis of recurrence in his progeny and/or sibship, while its ignorance will compromise genetic counseling due to the possible difficulties in detecting large deletions by standard molecular mutation analysis. Recognition of this syndrome in newborns without known familial risk for retinoblastoma is even more important as it is a clear warning sign that indicates immediate ophthalmic examination.

Child, Preschool↗

Registration of congenital anomalies in Switzerland by EUROCAT.

Since 1988 the epidemiological surveillance of congenital anomalies (malformations, chromosomal aberrations, metabolic diseases, hereditary diseases, neurosensorial defects, etc.) is carried out by the Swiss registry of EUROCAT (European Registry of Congenital Anomalies and Twins). Several Swiss cantons collaborate through their own local registry, transmitting data to the central registry in Lausanne. We present the main objectives and methods of registration and give the global prevalence rates for the main malformations for 1996 and the period 1993-1996.

Congenital Abnormalities↗

[Data on selected prenatal malformations in the EUROCAT study. Results of Zurich Canton from 1988 to 1997].

In the context of the EUROCAT study, data on selected congenital malformations and chromosome aberrations were collected from the Canton of Zurich (1988-1997). It was found that the major proportion of severe and early malformations, such as anencephalus and holoprosencephaly, were detected prenatally; for oral clefts and meningomyeloceles this was not the case, at any rate in regard to isolated (non-syndromic) malformations. However, if these defects occur in combination with a chromosome aberration, the likelihood of such a case being registered is higher. For the same reason, i.e. due to abnormal ultrasound findings and intrauterine growth retardation, trisomies 13 and 18 were more often detected prenatally than trisomy 21.

Congenital Abnormalities↗

[Trisomy 21 and its prenatal detection in the Canton of Vaud (1980-1996)].

We present a genetic and epidemiological study of trisomy 21 (T21) in the Canton of Vaud, the area covered by our local registry of congenital anomalies which has participated in EUROCAT Switzerland since 1988. During the period 1980-1996, we found 240 new T21 cases, all cytogenetically proven, out of 115,064 consecutive live births. Our purpose was to study trends and impact of biochemical screening and prenatal diagnosis of T21. We considered two different periods: 1980-1989 (before biochemical screening) and 1990-1996 (with screening) during which the mean maternal ages were respectively 28.4 years (10.6% > or = 35) and 29.2 years (12.9% > or = 35). The total prevalence of T21 was 2.08 per 1000; 5.4% of the cases were stillbirths, 49.6% were induced abortions and 45% livebirths. Prenatal cytogenetic diagnosis of trisomy 21 was performed in 52.1% of cases. Among women aged 35 or over the prenatal detection rates are superposable in the two periods. However, for younger women this rate has been much higher since the introduction of biochemical screening, i.e. 9.8% before and 51.8% after the introduction of triple test. In conclusion, the increase in prenatal diagnosis tests performed because of abnormal maternal serum marker levels has increased the global prenatal detection rate from 36.6% to 63.3% in our population, and the prevalence of Down syndrome has thus slightly decreased among livebirths.

Adult↗

[Turner syndrome].

This article is based on the study of 52 cases of Turner's syndrome, born between 1980 and 1996 and recorded in the Registry of Congenital Anomalies in the Canton of Vaud. In most cases the cytogenetic analysis was based on maternal multiple-marker screening, sonography findings or maternal age. The most common chromosome abnormality is complete monosomy X. The rare cases of mosaic and the one case of isochromosome mainly involve livebirths. Morphological analysis of foetuses revealed hygroma colli (84%) and hydrops (63%), frequently associated with major cardiac malformations. The livebirths present growth retardation, pterygium colli and facial dysmorphic features, but rarely complex malformations. In the light of our data, the probability of survival to birth is 0.8% and the prevalence in all clinical pregnancies is 1.1%.

Female↗

A new case of Pfeiffer syndrome with mutation in FGFR2.

We report on a sporadic case of Pfeiffer syndrome in a male newborn with complex craniosynostosis, broad thumbs and great toes and early demise. SSCP and direct sequencing revealed a missense mutation at position 1037 of the exon B (or IIIc) of the FGFR2 gene (codon 342) resulting in a cysteine to serine modification (TGC-TCC). Genotype-phenotype correlations between the FGFRs mutations and the different craniosynostotic syndromes are discussed.

Acrocephalosyndactylia↗

"C" trigonocephaly syndrome with diaphragmnatic hernia.

We report on a 6-year-old girl with C-trigonocephaly syndrome and diaphragmatic hernia. She is severely mentally retarded and shows the characteristic findings of this syndrome, including trigonocephaly, unusual facial features, especially intra-oral anomalies, low set and dysplastic ears, cardiac anomaly and neonatal hypotonia. Following our presentation at the 5th European meeting of dysmorphology in Strasbourg, P. Meinecke brought to our attention a case of C-trigonocephaly who died in the neonatal period from complications of a diaphragmatic hernia. Another case of C-trigonocephaly without diaphragmatic hernia was communicated to us by D. Lacombe. We report these three observations and present a review of 26 alleged cases.

Abnormalities, Multiple↗