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Biomedical subjects

G Viot

Publications and source records attributed to G Viot.

At least 19 recordsLinked to original sources
PubMed2006

[Autopsy findings related to Down's syndrome: 101 cases].

OBJECTIVES: To analyze the spectrum of congenital malformations among fetuses with Down's syndrome sent for necropsy. Materials and methods. Necropsies following medical termination of pregnancy during the second and third trimester were performed during a 4 year period. RESULTS: The incidence of each malformation was determined. Talipes equinovarus and aberrant lobation of the lung were present in 6% of cases. We are able to state precisely the incidence of 11 pairs of ribs: 11%. CONCLUSION: A precise knowledge about Down's syndrome associated malformations is essential for genetic counselling. The exact incidence of each sign is important to lead ultrasound examination when this syndrome is revealed.

Abnormalities, Multiple↗
PubMed2004

Atypical findings in Kabuki syndrome: report of 8 patients in a series of 20 and review of the literature.

Kabuki syndrome (KS) is a rare multiple congenital anomaly/mental retardation syndrome with an estimated frequency of 1/32,000 in Japan. Five major criteria delineate KS namely postnatal short stature, skeletal anomalies, moderate mental retardation, dermatoglyphic anomalies, and a characteristic facial dysmorphism. Here we report on a series of 20 sporadic KS patients and we focus on some rare and atypical features that we have observed: chronic and/or severe diarrhea (4/20) including celiac disease, diaphragmatic defects (3/20), pseudarthrosis of the clavicles (2/20), vitiligo (2/20), and persistent hypoglycemia (2/20). Other occasional findings were severe autoimmune thrombopenia, cerebellar vermis atrophy, and myopathic features. Interestingly, one of our KS patients presented with a clinical overlap with CHARGE syndrome (right eye microphtalmia with optic nerve coloboma, VSD, bilateral cryptorchidism, and severe deafness). Because these features are more frequent in our series than previously described, we propose to carefully investigate these manifestations during KS patient survey in an attempt to determine their real frequency and in order to improve clinical management.

Abnormalities, Multiple↗
PubMed2003

Congenital erythropoietic porphyria (Günther's disease): two cases with very early prenatal manifestation and cystic hygroma.

Congenital erythropoietic porphyria (CEP) or Günther's disease is the rarest form of the porphyrias. The disease is usually diagnosed at birth or during early infancy, but rarely in utero. We describe here the first two cases of very early prenatal expression of CEP with cystic hygroma diagnosed at 14 weeks in the first fetus and at 19 weeks in the second. Both fetuses presented with severe nonimmune hydrops fetalis as early as 19 and 22 weeks, associated with intrauterine growth retardation, hyperechogenic kidneys and bones. Amniotic fluid was dark brown and uro- and coproporphyrin I was dramatically increased. Molecular screening of the CEP gene detected heterozygous C73R mutation in both fetuses, the other parental mutation being as yet unknown.

Abortion, Eugenic↗
PubMed2002

Pregnancy outcome following prenatal diagnosis of an isodicentric X chromosome: first case report.

An isodicentric X chromosome, idic (X)(q27) was found in a female fetus during cytogenetic studies performed on amniotic cells due to advanced maternal age. No mosaicism was observed. Although segmental inversion duplications have been described for several other chromosomes, isodicentric chromosomes are reported only for gonosomes. Genetic counselling was based on ultrasound findings, cytogenetic replication studies and published cases of X chromosomes duplications ascertained pre- and postnatally. The pregnancy resulted in the birth of a healthy female infant.

Adult↗
PubMed2002

Homozygosity mapping of a Dyggve-Melchior-Clausen syndrome gene to chromosome 18q21.1.

Dyggve-Melchior-Clausen syndrome (DMC) is an autosomal recessive condition characterised by short trunk dwarfism, scoliosis, microcephaly, coarse facies, mental retardation, and characteristic radiological features. X rays show platyspondyly with double vertebral hump, epiphyseal dysplasia, irregular metaphyses, and a characteristic lacy appearance of the iliac crests. Electron microscopy of chondrocytes have shown widened cisternae of rough endoplasmic reticulum and biochemical analyses have shown accumulation of glucosaminoglycan in cartilage, but the pathogenesis of DMC remains unexplained. Here, we report on the homozygosity mapping of a DMC gene to chromosome 18q21.1 in seven inbred families (Zmax=9.65 at theta=0 at locus D18S1126) in the genetic interval (1.8 cM) defined by loci D18S455 and D18S363. Despite the various geographical origins of the families reported here (Morocco, Tunisia, Portugal, and Lebanon), this condition was genetically homogeneous in our series. Continuing studies will hopefully lead to the identification of the disease causing gene.

Abnormalities, Multiple↗
PubMed2002

[Confined placental mosaicism: definition, consequences and outcome].

Confined placental mosaicism (CPM) occurs in approximately 2 per cent of viable pregnancies studies by chorionic villus sampling. The great majority of pregnancies with confined placental mosaicism proceed uneventfully, resulting in normal liveborn infants. However, a few specific chromosomal abnormalities have been associated with fetal growth retardation. Fetal karyotype should be checked by amniocentesis and such pregnancies should have careful ultrasound follow-up.

Amniocentesis↗
PubMed2001

Twelve novel mutations in the tissue-nonspecific alkaline phosphatase gene (ALPL) in patients with various forms of hypophosphatasia.

Hypophosphatasia is a rare inherited disorder characterized by defective bone mineralization and deficiency of serum and tissue liver/bone/kidney tissue alkaline phosphatase (L/B/K ALP) activity. We report here the characterization of tissue-nonspecific alkaline phosphatase (TNSALP) gene mutations in a series of 11 families affected by various forms of hypophosphatasia. Nineteen distinct mutations were found, 7 of which were previously reported. Eleven of the 12 new mutations were missense mutations (Y11C, A34V, R54H, R135H, N194D, G203V, E218G, D277Y, F310G, A382S, V406A), the last one (998-1G>T) was a mutation affecting acceptor splice site.

Adult↗
PubMed2001

[Rectal self-mutilation, rectal bleeding and Prader-Willi syndrome].

UNLABELLED: Prader-Willi syndrome is a genetic disorder characterized by infantile hypotonia, obesity, hypogonadism and mental retardation. Individuals with Prader-Willi syndrome manifest a severe skin picking behavior, including rectal picking. CASE REPORT: We report the case of a girl (12 years old) with this syndrome in whom rectal picking resulted in rectal bleeding and solitary rectal ulcer. CONCLUSION: Caregivers of children with Prader-Willi syndrome should be aware of a potential rectal picking behavior, which results in significant bleeding. Early recognition of such a behavior helps to avoid misdiagnosis.

Child↗
PubMed2001

Prenatal diagnosis of fetal tail and postabortum anatomical description.

Fetal ultrasound examination at 13 weeks of gestation demonstrated a homogeneously echogenic protrusion, or tail, 7 mm in length, in the sacral region. At 15 weeks, the ultrasound appearance was consistent with a regression of the tail and by 21 weeks it had completely disappeared. Severe intrauterine growth restriction with reduced uterine blood flow was diagnosed at 21 weeks and intrauterine death occurred at 24 weeks of gestation. Postmortem examination revealed a 4-mm caudal appendage which contained no vertebrae on radiography. The appendage was located under and behind the last sacral vertebra suggesting a true vestigial tail with a delayed process of regression.

Adult↗
PubMed2001

Inversion of the circadian rhythm of melatonin in the Smith-Magenis syndrome.

OBJECTIVE: The objective was to determine the circadian rhythm of melatonin in the Smith-Magenis syndrome (SMS), which causes behavioral problems and sleep disturbance. STUDY DESIGN: Questionnaires, sleep consultations, and sleep diaries were obtained in 20 children with SMS (9 girls, 11 boys aged 4 to 17 years). Actigraphy, electroencephalography, and the circadian variations of plasma melatonin, cortisol, and growth hormone were recorded in 8 patients. Early sleep onset, early sleep offset, and sleep attack indicated sleep disturbance. RESULTS: All children with SMS had a phase shift of their circadian rhythm of melatonin. Time at onset of melatonin secretion was 6 AM +/- 2 (control group: 9 P.M. +/- 2). Peak time was 12 PM +/- 1 (control group: 3:30 AM +/- 1:30), and melatonin offset was at 8 PM +/- 1 (control group: 6 AM +/- 1). Behavioral problems correlated with the inverted circadian rhythm of melatonin. CONCLUSION: Considering that clock genes mediate the generation of circadian rhythms, we suggest that haploinsufficiency for a circadian system gene mapping to chromosome 17p11.2 may cause the inversion of the circadian rhythm of melatonin in SMS.

Abnormalities, Multiple↗
PubMed2000

Apparent Sotos syndrome (cerebral gigantism) in a child with trisomy 20p11.2-p12.1 mosaicism.

We report on a child with apparent Sotos syndrome (cerebral gigantism) and partial duplication of the short arm of chromosome 20 mosaicism. Trisomy 20p11.2-p12.1 was diagnosed using cytogenetic and FISH studies. The somatostatin receptor 4 (SSTR4) gene is included in the duplicated segment. This suggests that a dosage effect of this gene might be related to some of the clinical findings observed in our patient. The present observation emphasizes the importance of chromosome analysis in patients with well-delineated but sporadic conditions.

Adult↗
PubMed2000

Subtle familial unbalanced translocation t(8;11)(p23.2;p15.5) in two fetuses with Beckwith-Wiedemann features.

We describe a subtle translocation t(8;11)(p23.2;p15.5) ascertained after two induced abortions in the same sibship because of the discovery of fetal hydrops on ultrasound examination. Initial cytogenetic studies performed on cultured amniotic fluid cells were considered as normal in both fetuses. High resolution banding analysis and FISH studies performed on the parents' chromosomes revealed a paternal translocation t(8;11)(p23.2;p15.5). Retrospective FISH analysis of both fetuses showed that they carried the same chromosomal imbalance including a distal monosomy 8pter and a distal trisomy 11pter. The phenotypes of the fetuses were re-examined and found to be compatible with Beckwith-Wiedemann syndromes (BWS). FISH analysis using an IGF2 probe demonstrated the presence of three copies of the IGF2 gene. This study highlights the value of searching for subtle chromosome rearrangements in families with recurrent unexplained multiple malformation syndromes discovered prenatally. Also, it contributes to a better delineation of the prenatal phenotype of BWS. Finally, it sheds new light on the aetiology of non-immune hydrops fetalis.

Adult↗
PubMed1999

Chediak-Higashi syndrome associated with maternal uniparental isodisomy of chromosome 1.

Chediak-Higashi syndrome (CHS) is a rare autosomal recessive disorder (incidence around 1 in 106 births), characterised by a complex immunologic defects, reduced pigmentation, and presence of giant granules in many different cell types. It most likely results from defective organellar trafficking or protein sorting. The causative gene (LYST) has recently been identified and shown to be homologous to the beige locus in the mouse. CHS has always been reported associated with premature-termination-codon mutations in both alleles of LYST. We report a unique patient with CHS, who was homozygous for a stop codon in the LYST gene on chromosome 1 and who had a normal 46,XY karyotype. The mother was found to be a carrier of the mutation, whereas the father had two normal LYST alleles. Non-paternity was excluded by the analysis of microsatellite markers from different chromosomes. The results of 13 informative microsatellite markers spanning the entire chromosome 1 revealed that the proband had a maternal isodisomy of chromosome 1 encompassing the LYST mutation. The proband's clinical presentation also confirms the absence of imprinted genes on chromosome 1.

Alleles↗
PubMed1999

SHOX gene mutations and deletions in dyschondrosteosis or Leri-Weill syndrome.

Dyschondrosteosis is an autosomal dominant form of mesomelic dysplasia that is often combined with a deformity of the forearms called Madelung deformity. Based on the observation of X-Y translocations (p22,q12) in patients with dyschondrosteosis, the authors tested the pseudoautosomal region in eight affected families and showed linkage of the dyschondrosteosis gene to a microsatellite DNA marker at the DXYS233 locus (Zmax = 6.26 at theta = 0). Since the short stature homeobox-containing gene (SHOX) involved in idiopathic growth retardation and possibly Turner syndrome maps to this region, SHOX was regarded as a strong candidate gene for dyschondrosteosis. This article reports the detection of large-scale SHOX deletions in seven of the eight families and a nonsense mutation of SHOX in the remaining family affected with dyschondrosteosis. Additional evidence suggests that Langer mesomelic dwarfism results from homozygous mutations at the genetic locus responsible for dyschondrosteosis.

Bone Diseases↗
PubMed1999

Prenatal detection of a 1p36 deletion in a fetus with multiple malformations and a review of the literature.

The prenatal diagnosis of a 1p36 deletion is reported. The pregnancy was ascertained at 24 weeks of gestation because of the discovery of multiple malformations at ultrasound including hypotelorism, moderate cerebral ventricular dilatation and Ebstein anomaly with secondary cardiac failure. Following cytogenetic studies and counselling, the pregnancy was terminated and a fetal autopsy performed. The phenotype of this antenatally-diagnosed case is compared with the clinical features of 44 previously reported cases with an identical deletion of the short arm of chromosome 1p36.

Abnormalities, Multiple↗