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Biomedical subjects

E Vamos

Publications and source records attributed to E Vamos.

At least 19 recordsLinked to original sources
PubMed2004

Assessment of an electron-impact GC-MS method for organic acids and glycine conjugates in amniotic fluid.

We assessed the reliability of a method designed for common electron-impact GC-MS systems to determine in a single run most organic acids and glycine conjugates of clinical interest in amniotic fluid. Suitable sensitivity was achieved by dividing the selected-ion chromatogram into 12 time segments during which the monitoring dwelt on specific ions. Twelve metabolites were simultaneously quantified in amniotic fluid, with performances ranging from very good to clinically acceptable. The total coefficient of variation was 2.5-14.1% and the detection limit was well below the lower value of the physiological range. For five other metabolites, the precision was lower and/or the detection limit was near the physiological range. The method was clinically assessed by the prenatal detection of three cases of tyrosinaemia type I and one case of propionic acidaemia. Analytical and clinical evaluation of the method showed that GC-MS with electron-impact fragmentation can be an informative analytical approach for low-level organic acids in physiological fluids. Apart from the case of glycine conjugates, the method shows a fair reliability for amniotic fluid analysis, which might warrant its use for prenatal diagnosis of organic acidurias. However, this method cannot replace procedures using isotopic internal standards, nor GC-MS based on chemical ionization fragmentation, which remain confirmatory analytical methods of choice.

Amino Acid Metabolism, Inborn Errors↗
PubMed2002

[Medical genetics service].

Created in 1987, the department of medical genetics finds its origins in molecular endocrinology research which had developed from the seventies at the Institut de Recherche Interdisciplinaire en Biologie Humaine et Moléculaire (IRIBHM) of the Faculty of Medicine. After its fusion with the Center of Human Genetics of the ULB, in 1992, the department is composed of three units: the lab of molecular genetics and oncology, the lab of cytogenetics and a clinical genetics unit. One thousand consultations of genetic counseling and more than 15,000 molecular or cytogenetic diagnostic procedures are performed annually. The development of the clinical activities was paralleled by a very active research activity, resulting in a series of "firsts". Amongst the main results are: the identification of the first mutations responsible for congenital hypothyroidism; the molecular cloning of the TSH receptor and of a series of "orphan" G protein-coupled receptors; the identification of a novel neuropeptide, nociceptin, by the first example of "reverse pharmacology"; the identification of olfactory receptors on the sperm of mammals, including man; the identification in molecular terms of the mechanisms responsible for acquired and hereditary hyperthyroidisms; the identification of the chemokine receptor CCR5 as the major coreceptor of HIV-1, and of the prevalent mutation of CCR5 conferring resistance to HIV to about 1% of the European population.

Belgium↗
PubMed2001

[Individual genetic counseling and collective screening strategies in particular at-risk populations].

Carrier screening for recessive disorders together with prenatal diagnosis offered in at risk pregnancies can achieve efficient prevention of genetic diseases occurring with particularly high frequencies in specific populations. In this context, genetic counseling, which should be available to each at risk couple, must be integrated into a more elaborate framework geared towards informing the target population. Dramatically different outcomes of carrier screening programmes implemented in the past illustrate the conditions for success or failure. The need to target selected ethnic groups accounts for most of the problems encountered: underpriviledged minorities, risk of discrimination and, most importantly, cultural gaps leading to refusal of prenatal diagnosis and/or of selective abortion. In order to achieve prevention through screening programmes, the tests should therefore be preceded by dissemination of adequate information into the target population, followed by genetic counseling for at risk couples, addressing cultural differences. Prenatal diagnosis should always be proposed, but never imposed on these couples. Finally, these screening programmes must be underpinned by comprehensive subsidies covering not only the tests but also education and counseling that should always be provided with the tests. In terms of public health, this is the price for a cost-effective genetic screening programme.

Abortion, Therapeutic↗
PubMed2000

Further evidence for autosomal dominant inheritance and ectodermal abnormalities in Kabuki syndrome.

Most cases with Kabuki syndrome (KS) were reported sporadically. Recently, a few familial cases of KS were reported. This report provides further evidence that the KS is inherited as a dominant trait with variable expressivity. The proposita is an 18-month-old girl with facial findings characteristic of Kabuki syndrome, prominent fingertip-pads, a midsagittal cleft of vertebral body D4, hypotonia, and psychomotor retardation. Her mother had a similar facial appearance, prominent, cup-shaped ears, an abnormal dentition, early breast development, and low-normal intelligence. Because mother and daughter both had evident Kabuki syndrome, we conclude that KS in this family is inherited as a dominant trait. Further family history supports this finding. Microscopic examination of the hair of the proposita shows abnormalities consisting of trichorrhexis nodosa, twisting of the hairshafts, and irregularity of the diameter of the hair, as was described recently in a patient with KS. This could be another occasional finding in this syndrome, but further studies are required. The presence of abnormal hair, nails, and the commonly described tooth abnormalities in KS further suggest ectodermal involvement in this syndrome.

Abnormalities, Multiple↗
PubMed2000

Cutaneous porphyria in a neonate with tyrosinaemia type 1.

UNLABELLED: A term infant born to consanguineous parents presented at birth with hypoglycaemia, thrombocytopenia, coagulopathy and hyperbilirubinaemia associated with polycythaemia due to delayed cord clamping. Despite phototherapy and correction of polycythaemia by partial exchange transfusion, coagulopathy, hypoglycaemia and conjugated hyperbilirubinaemia persisted, suggesting hepatic failure. Metabolic work-up led to the diagnosis of tyrosinaemia type 1 on day 4. Two--(2-nitro-4-trifluoromethylbenzoyl)--1,3 cyclohexanedione (NTBC) treatment, started on day 5, resulted in progressive clinical improvement and unambiguous biochemical response. Severe skin purpuric lesions occurred in areas exposed to phototherapy. These resolved slowly after its discontinuation. Urine analysis sampled just before and 6 days after starting NTBC treatment showed high levels of type 1 coproporphyrin isomers. Such findings do not seem directly related to tyrosinaemia type 1 where succinylacetone inhibits delta-aminolevulinic acid (delta-ALA) dehydratase and where the accumulation of delta-ALA results in neurotoxicity without photosensitivity. CONCLUSION: We describe a cutaneous form of porphyria in a neonate presenting with severe liver failure due to tyrosinaemia type 1. This porphyria is tentatively attributed to a secondary accumulation of coproporphyrins due to cholestasis, as reported in the bronze baby syndrome and recently described in neonates with purpuric phototherapy-induced eruption, rather than to a primary defect of porphyrin metabolism. The hypothesis of a direct effect of tyrosinaemia type 1 on porphyrin excretion is also discussed.

Combined Modality Therapy↗
PubMed2000

Preimplantation genetic diagnosis for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency.

Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is the most common defect in fatty acid oxidation. The disease is inherited in an autosomal recessive fashion (carrier frequency around 1 in 70) and probably affects as many as 1 in 10000 new-borns. Affected children usually present within the two first years of life with recurrent episodes of hypoketotic hypoglycaemia and lethargy leading to death in approximately 25% of the cases. One mutation (c985A-->G) accounts for approximately 90% of the carrier chromosomes. We developed a preimplantation genetic diagnosis (PGD) strategy for MCAD for a couple who had already lost two affected children. When tested on heterozygous lymphoblasts, the amplification efficiency was 67 out of 71 (94%) and the allele drop-out rate was 0 out of 67. The patient became pregnant after one PGD cycle during which two embryos were replaced. The twin pregnancy was checked by chorionic villus sampling (CVS) and was shown to be unaffected. The twins have been born and are healthy.

Acyl-CoA Dehydrogenase↗
PubMed1999

Delineation of two distinct 6p deletion syndromes.

Deletions of the short arm of chromosome 6 are relatively rare, the main features being developmental delay, craniofacial malformations, hypotonia, and defects of the heart and kidney, with hydrocephalus and eye abnormalities occurring in some instances. We present the molecular cytogenetic investigation of six cases with 6p deletions and two cases with unbalanced translocations resulting in monosomy of the distal part of 6p. The breakpoints of the deletions have been determined accurately by using 55 well-mapped probes and fluorescence in situ hybridization (FISH). The cases can be grouped into two distinct categories: interstitial deletions within the 6p22-p24 segment and terminal deletions within the 6p24-pter segment. Characteristics correlating with specific regions are: short neck, clinodactyly or syndactyly, brain, heart and kidney defects with deletions within 6p23-p24; and corneal opacities/iris coloboma/Rieger anomaly, hypertelorism and deafness with deletions of 6p25. The two cases with unbalanced translocations presented with a Larsen-like syndrome including some characteristics of the 6p deletion syndrome, which can be explained by the deletion of 6p25. Such investigation of cytogenetic abnormalities of 6p using FISH techniques and a defined set of probes will allow a direct comparison of reported cases and enable more accurate diagnosis as well as prognosis in patients with 6p deletions.

Adult↗
PubMed1998

Prenatal diagnosis of a constitutional interstitial deletion of chromosome 5 (q15q31.1) presenting with features of congenital contractural arachnodactyly.

Prenatal diagnosis of a constitutional interstitial deletion of chromosome 5 (q15q31.1) in a 30-year-old woman is reported. At 21 weeks of pregnancy, routine fetal ultrasounds showed the presence of apparently isolated bilateral club feet. Fetal karyotyping documented an interstitial deletion of the long arm of chromosome 5: 46,XX,del(5) (q15q31) in all 50 analyzed metaphases. Because such deletion is associated with severe psychomotor retardation, the pregnancy was terminated. Postmortem karyotyping of skin fibroblasts confirmed the presence of this interstitial de novo deletion in all mitoses. The breakpoints on 5q were analyzed by fluorescent in situ hybridization and were localized at 5q15 and q31.1. This case illustrates the importance of fetal karyotyping in cases of isolated club feet. At autopsy, the fetus presented had minor anomalies and contractures of knee and hip joints. These clinical findings could fit the diagnosis of congenital contractural arachnodactyly (CCA) or Beals syndrome. CCA is caused by a defect in the fibrillin-2 (FBN2) gene. This gene was previously mapped on 5q23-31. Our molecular studies of both parents and the fetus, using an intragenic polymorphic GT repeat, showed that the FBN2 gene was deleted in the fetus and that the de novo interstitial deletion occurred on the paternally inherited chromosome 5. Thus, CCA may be caused by a loss of function of the FBN2 gene. Clinical findings in this fetus and those of other described cases with interstitial 5q deletions are reviewed, and similarities with CCA are stressed.

Abnormalities, Multiple↗
PubMed1998

Noonan-like phenotype in monozygotic twins with a duplication-deficiency of the long arm of chromosome 18 resulting from a maternal paracentric inversion.

We report on newborn monozygotic twins with a Noonan-like phenotype, and multiple congenital anomalies due to a monocentric recombinant chromosome 18. The mother carried a paracentric inversion of the long arm of chromosome 18, inv(18)(q21.1q22.3). Cytogenetic, fluorescent in situ hybridization, comparative genomic hybridization and DNA marker analyses allowed the delineation of the deleted (18q22.3-qter) and duplicated (18q12.1-q21.1) chromosomal regions in the recombinant chromosome 18, and suggest that this duplication-deletion chromosome 18 resulted from breakage of a dicentric recombinant chromosome 18 with subsequent reconstitution of telomeric sequences on the long arm. Marked variability is observed in the phenotypic expression of the same chromosomal anomaly in these monozygotic twins. The clinical findings of these patients are compared with those reported in proximal 18q-duplication and distal 18q-deletion patients. The clinical features of both infants are compatible with Noonan syndrome, suggesting that a locus for this syndrome may be located on the long arm of chromosome 18.

Chromosome Deletion↗
PubMed1998

Need for search for cryptic translocation in parents with several children affected with MCA: report of a cryptic translocation (10;14) detected by FISH.

The 3 affected children from 2 different wedlocks of the mother have been previously described (11). Search by FISH analysis in the mother revealed she is a carrier of balanced translocation of clear terminal G bands of equal sizes of the long arms of chromosomes 10 and 14. Chromosomal slides of the last child (Patient 3) could be analysed by fish and revealed that he did inherit the derivative chromosome 10. He had a partial trisomy 14 and a partial deletion of the long arm of chromosome 10. The clinical pictures correspondence to the possibly abnormal karyotypes will be discussed.

Abnormalities, Multiple↗
PubMed1998

Alveolar soft-part sarcoma: further evidence by FISH for the involvement of chromosome band 17q25.

A cytogenetic study of an alveolar soft-part sarcoma, a rare tumor of probably myogenic origin, demonstrated a t(X;17)(p11;q25) as the sole chromosomal abnormality. Dual- and triple-color fluorescence in situ hybridization, performed on metaphase and interphase cells, confirmed the translocation between chromosomes X and 17 and demonstrated that this translocation resulted in loss of 17q25. Involvement of 17q25 has been described in four previously published cases of alveolar soft-part sarcoma, but without further characterization. Compared to our karyotype, it seems that the derivative chromosome 17 observed in the reported cases could also be the result of a t(X;17) with possible loss of the 17q25 band. If so, a 17q25 deletion and/or chromosome rearrangement between Xp and 17q leading either to a gene fusion or gene disruption could play an important role in the pathogenesis of alveolar soft-part sarcoma.

Child↗
PubMed1997

Feingold syndrome: report of a new family and review.

Feingold syndrome (or oculodigitoesophagoduodenal syndrome; Microcephaly, Mesobrachyphalangy, Tracheo-esophageal fistula syndrome) is a dominantly inherited combination of hand and foot abnormalities, microcephaly, esophageal/duodenal atresia, short palpebral fissures and learning disabilities, first reported in 1975 (MIM 164280). We report on the seventh family with Feingold syndrome. The propositus is a male infant with esophageal and duodenal atresia, brachymesophalangy of the fifth fingers, bilateral syndactyly of toes 4-5 (and 2-3), relative microcephaly, and facial anomalies. His mother also has microcephaly, similar facial appearance, short fifth fingers with single flexion crease, syndactyly of toes 4-5, and learning disabilities. The maternal sister, brother, and grandmother of the propositus have the same phenotype. The 7 families with Feingold syndrome are reviewed. Intestinal (esophageal/duodenal) atresia/obstruction occurs in approximately 1/3 of the patients with Feingold syndrome.

Abnormalities, Multiple↗
PubMed1997

Interstitial deletion 2q33.3-q34 in a boy with a phenotype resembling the Seckel syndrome.

A boy presented at 5 weeks with a syndrome of pre- and postnatal growth retardation, microcephaly, muscular hypotonia, and facial anomalies resembling those seen in Seckel syndrome or microcephalic primordial dwarfism I. Analysis of prometaphase chromosomes, fluorescent in situ hybridization (FISH), and molecular studies showed the presence of a de novo chromosome 2 deletion that could be defined as del(2)(q33.3q34)pat. Parental chromosomes were normal, except for the presence of a paternal supernumerary marker identified by FISH as der(15). On follow-up of the patient during the next months length development appeared normal and the diagnosis of Seckel syndrome was withdrawn. Clinical findings of previously published cases with interstitial deletion of at least 2q33.3-q34, the deletion present in the propositus, are reviewed and include pre- and postnatal growth retardation, psychomotor retardation, microcephaly, micrognathia, and abnormal/low-set ears; findings also present in the propositus. These findings resemble those described in the Seckel syndrome. Noteworthy is the finding that 2/3 of the 60 reviewed cases originally reported as having Seckel syndrome apparently belong to a heterogeneous group of low birth weight microcephalic dwarfism I yet to be clearly defined. In these patients no chromosome 2q deletion has been reported so far. Retrospective analysis could show if a subgroup of these patients carry submicroscopic deletions at 2q33.3-q34. Alternatively, molecular analysis of this region may be warranted in newly diagnosed patients with Seckel syndrome-like manifestations.

Abnormalities, Multiple↗
PubMed1997

Acrocallosal syndrome in an Algerian boy born to consanguineous parents: review of the literature and further delineation of the syndrome.

We present a 17-month-old boy with the acrocallosal syndrome. He was born to consanguineous parents. Abnormal findings included agenesis of the corpus callosum, a ventricular septal defect (VSD), postaxial polydactyly of fingers, cleft soft palate, intestinal malrotation, large anterior fontanelle, prominent forehead, hypertelorism, epicanthic folds, short nose and mandible and preauricular skin tags, mixed hearing loss, laryngomalacia, and growth and severe motor and mental retardation. A review of previous reports on the acrocallosal syndrome shows considerable clinical variability; minimal diagnostic criteria are proposed. A developmental field defect with disturbance of midline development is suggested.

Abnormalities, Multiple↗
PubMed1997

Growth failure, encephalopathy, and endocrine dysfunctions in two siblings, one with 5-oxoprolinase deficiency.

UNLABELLED: Two female siblings, born to consanguineous parents, presented with a similar phenotype characterized by severe growth and developmental failure, dysmorphic features, thyroid and gonadal dysfunction, autistic traits and hand stereotypes resembling Rett syndrome. In the elder patient, analysis of urinary organic acids disclosed a very high excretion of 5-oxoproline (4.2 to 8.1 mol/mol creatinine) and enzyme assays of leucocyte extracts revealed a profound deficiency of 5-oxoprolinase. However, normal urinary organic acid profiles were found in the younger child. In view of their distinct dysmorphic features and severe growth deficiency, these siblings cannot be considered as Rett Syndrome variants. The Dubowitz and carbohydrate-deficient glycoprotein syndromes were also excluded clinically and biochemically respectively. We conclude that these patients suffer from a hitherto undescribed autosomal recessive disorder, unrelated to the 5-oxoprolinase deficiency of the elder sib. CONCLUSION: The present findings give evidence that 5-oxoprolinase deficiency is not associated with a distinct morbid phenotype.

Brain Diseases↗
PubMed1997

A probable case of Wiedemann-Rautenstrauch syndrome or neonatal progeroid syndrome and review of the literature.

A boy with features suggesting the diagnosis of Wiedemann-Rautenstrauch syndrome (WRS) or neonatal progeroid syndrome is presented. Abnormal findings included a generalized virtual absence of subcutaneous fat, sparse scalp hair, prominence of veins and muscles, a large and persistent anterior fontanelle and facial dysmorphism (triangular aged face, prominent eyes and scalp veins). Until now, only 13 cases (including one prenatal diagnosis) of this syndrome have been described. Since the borderlines of this syndrome are not very exact, we reviewed the previous reports in order to further delineate this rare syndrome.

Adipose Tissue↗
PubMed1997

New syndrome or severe expression of Gordon syndrome? A case report.

A boy with multiple congenital anomalies including median cleft palate, bilateral hearing loss, clino- and camptodactyly, bilateral single palmar flexion creases, severe hypotonia with kyphoscoliosis and respiratory insufficiency, failure to thrive, bilateral cryptorchidism and facial dysmorphism (epicanthus, a flat nasal bridge, a small mouth, a small nose with anteverted nostrils, low-set ears, a prominent forehead, microretrognathia) is presented. His mother has a median cleft palate, bilateral hearing loss, single palmar flexion creases, and short stature. An autosomal or X-linked dominant syndrome with more severe expression in the proband than in his mother is suggested.

Abnormalities, Multiple↗