Biomedical subjects

S González-Ferrer

Publications and source records attributed to S González-Ferrer.

8 recordsLinked to original sources

PubMed1998

[Clonal chromosome abnormalities in malignant hematological diseases using fluorescence in situ hybridization].

Fluorescent in situ hybridization (FISH) is a rapid, sensitive and reliable method for the identification of complete chromosomes, or segments of them, during metaphase or nuclear interphase. The present study shows the results of the analysis of 32 bone marrow aspirates from patients with malignant hematological diseases (11 AML, 7 ALL, 12 CML and 2 CLL), referred to the Medical Genetics Unit of the Faculty of Medicine, Zulia University, Maracaibo, Venezuela between 1994 and 1996. All samples were studied by conventional and molecular techniques (FISH), using probes of total chromosomes, alpha-satellites and locus specific. In patients with AML and ALL and FISH technique detected clonal chromosomal abnormalities, that were not found by the conventional cytogenetic technique. Furthermore, the PML-alpha RARA complex was identified in the promyelocytic acute leukemias. The presence of the molecular complex ABL-BCR was also demonstrated in CML. The present study demonstrates the usefulness of the FISH technique in the detection of clonal chromosomal abnormalities, which are important when considering the clinical care of patients with these pathologies.

Adolescent↗

PubMed1998

[Prenatal diagnosis. II. Importance of ultrasonographic markers in prenatal diagnosis of chromosome abnormalities].

The Medical Genetic Unit of the University of Zulia (MGUUZ) has developed a Prenatal Diagnosis Program (PDP) since January-1993, in which Genetic Risk Factors are determined in couples who request prenatal genetic counseling. In this program, different prenatal diagnostic procedures are performed to detect congenital defects during intrauterine life. One of these procedures is the Fetal Sonogram (FS). FS is a non invasive technique which permits the prenatal diagnosis of many genetic dysmorphic syndromes. Through the search of abnormal specific characteristics in the fetus, chromosomopathies may be suspected. These findings are named "Echosonographic Markers of Chromosomal Abnormalities" (EMCA). During three years (January-1993 to December-1996), patients attended in the PDP included 321 pregnant women in which 312 FS were performed. Abnormal outcomes were 22 (17 with isolated congenital malformations and 5 with EMCA). Only one fetus with chromosome abnormality (46,XX21q-) could not be detected by FS. The goals of this paper are: 1) to report 5 patients with sonographic markers suggestive of chromosomal abnormalities and 2) to show the FS usefulness in prenatal diagnosis of chromosompathies. We conclude that, in the search of the EMCA the FS should be offered systematically to all pregnant women without recognizable genetic risk. They are the main group with optimal reproductive age and in consequence, with the possibility of having a relatively major number of conception outcomes with congenital defects, with or without chromosomic etiology. The majority of those defects can be detected by FS and could allow us to select the patients in which the use of an invasive prenatal diagnostic procedure could be justified.

Adolescent↗

PubMed1998

[Diagnosis and management of patients with sex differentiation disorders: experience at the Unit of Medical Genetics of the University of Zulia, Maracaibo, Venezuela].

Abnormalities of sexual differentiation (ASD) represent a group of entities, heterogeneous in their etiopathogenesis and clinical manifestations. In order to characterize and analyze the epidemiologic, clinical, endocrine and genetic aspects of patients with ASD consulting UGM-LUZ between 1971-1996, the families that had at least one of its members affected were evaluated. Strict diagnostic criteria to each entity were applied. Cytogenetic, hormonal, radiological, echographic and anatomopathological evaluations were done in each patient. From 391 families, 429 patient consulted with ASD. They represent 5.4% of the patient who consulted to UGM-LUZ in the same period. 214 (50%) patients with definitive diagnosis of ASD were identified to fill the established inclusion criteria. The distribution was the following: 139 with anomalies of the sexual chromosomes; 36 with congenital adrenal hyperplasia; 21 with complete androgen insensitivity syndrome; 14 with mixed gonadal dysgenesis; and 4 with true hermaphroditism. 183 (42.7%) patients with male pseudohermaphroditism and 17 (3.9%) with female pseudohermaphroditism were diagnosed as they did not fulfill the established diagnostic criteria. 15 (3.4%) patients presented ASD associated to a polymalformative syndrome. The ASD are very complex entities, they need the participation of an interdisciplinary team for their diagnosis and management process.

Adolescent↗

PubMed1996

[Chronic myeloid leukemia. Karyotype changes].

Chronic Myeloid Leukemia (CML) is a clonal disease of bone marrow, citogenetically characterized by the presence of the Philadelphia chromosome (Ph). Additional anomalies in the Ph cromosome have been found during the evolution of CML. This paper will show evidence of cytogenetic abnormalities during the evolution of CML in this region, and its correlation with clinical evolution. 55 samples of bone marrow, 81.3% (45/55) in chronic phase (CP), 12.7% (7/55) in an accelerated phase (AP), and 5.4% (3/55) in blastic phase (BP) were received. In 12/45 patients in CP the karyotype was repeated at least once a year during the evolution of their illness. 9/12 presented the Ph chromosome as a single anomaly at the moment of diagnosis; the other 3 presented a distinct anomaly. 4/9 presented additional abnormalities moving to the stages AP or BP between 4-8 months after initial discovery. 7/10 patients referred in AP or BP presented additional abnormalities in the Ph chromosome. It is evident that the chromosome study of each patient with CML must be carried out at least once a year in order to detect chromosomal abnormalities in addition to the Ph chromosome. Thus, a greater therapeutic control of the disease is possible.

Adult↗

PubMed1996

[Leigh's encephalopathy (subacute necrotizing encephalopathy). Documentation of its evolution through neuroimaging].

A 30 months-old boy developed bilateral nistagmus, tremor, gait disturbance, hypotonia and disartria. The diagnose of Leigh encephalopathy was suggested on the basis of clinical, neuroimaging and laboratory findings. Computed tomography and magnetic resonance imaging (MRI) at an early stage revealed bilateral and symmetric lesions in the putamen, appearing as hyperintense signal on T2-weighted images. Twelve months later a relatively large hypertense area in the posterior brainstem was observed. At this stage, the patient exhibited marked deterioration, dystonic manifestations, rigidity and respiratory disturbances. He died 6 months later for respiratory arrest during bronconeumonic infection. We believe MRI is a valuable means to allow assessment of the evolution of the disease.

Child, Preschool↗

PubMed1995

[Hereditary diseases and congenital malformations at the Unit of Medical Genetics of the University of Zulia. Years: 1983-1992].

The Medical Genetics Unit at Universidad del Zulia (UGM-LUZ) gives counsel to patients with partial and total genetic diseases. Counseling is available for patients of both sexes and all ages, from public and private health centers and several medical specialities. In the present study an analysis of 4617 clinical records from families referred for genetic counseling to the UGM-LUZ is given. The study spans from January 1983 to December 1992. Fifty four (1.2%) of these histories correspond to pre-nuptial counseling, 773 (16.7%) pre-conceptional, 316 (6.8%) pre-natal and 3474 (75.3%) for diagnosis. A computerized system was developed, based on relational data base manager, that permits access with interactive Dbase type applications. A total of 5433 diagnoses were made. The most frequent causes of genetic diseases were chromosomal abnormalities (12.32%), mainly Down and Turner syndromes. Mendelian diseases occupied 14.45% of all cases, with Marfan and Noonan syndrome, Osteogenesis imperfecta. Duchenne-Becker muscular dystrophy and Incontinentia Pigmenti as the most frequent syndromes. Diseases that involve multifactorial inheritance, such as neural tube defects, accounted for 7.36% of all diagnosis. Effects of teratogenic agents such as german measles, radiations and others were detected in 3.96% of all cases. In 8.5% of the patients a hereditary factor was suspected. No definitive diagnosis was reached in 32.45% of all cases and 20.96% of the patients were normal. The need for data from other medical genetic centers is stressed. In this way the regional and national genetic diseases on morbidity can be known.

Adolescent↗

PubMed1994

[Application of the high resolution chromosomic technic in patients in high risk of cytogenetic anomalies].

Since the beginning of cytogenetics, there has been a constant improvement of chromosomal culture and banding techniques. In 1976, Yunis described a high chromosomal resolution technique (HRC), that permits the detection of subtle chromosomal abnormalities. The present work, reports the results obtained when HRC was applied to the study of chromosomal abnormalities in patients with high risk of such. The study comprised 434 specimens of venous blood and 182 bone marrow aspirates. The samples were classified according to the presuntive diagnoses. The highest frequency of chromosomal abnormalities, was found in blood samples from patients with physical deformities with or without mental retardation (22.22%), followed by mental retardation autism and/or fragile X chromosome (13.66%), and in couples with reproductive disorders (5.8%). In bone marrow, the most frequent abnormalities corresponded to patients with chronic myeloid leukemia (78.43%), acute lymphocytic leukemia (62.10%), acute myeloide leukemia (61.9%), myelodisplastic syndromes (43.7%) and chronic lymphocytic leukemia (14.2%). The present results stress the need to apply the HRC technique when the probability of minute chromosomal abnormalities is high.

Chromosome Aberrations↗

PubMed1994

[Hallervorden-Spatz syndrome in 2 Venezuelan patients].

Hallervorden Spatz syndrome (HSS), described in 1.922, is a rare progressive disorder recessively inherited involving the basal ganglia. It is manifested clinically by mental deterioration, rigidity, choreoathetosis and spasticity evident during the first two decades of life. Increased concentration of iron in the globus pallidus and substantia nigra has been demonstrated convincingly. the objective of this paper is to describe two venezuelan children with this syndrome. Patient 1 is a 14-year-old boy with progressive impairment of language, mental deterioration and slowing of voluntary movements started at the age of 8 years. Patient 2 is a young girl first examined at 8 years of age because of psychomotor development delay, progressive impairment of gait, rigidity of the limbs, progressive dystonia and mental deterioration. Multiple test were performed, including metabolic studies, CT scan and magnetic resonance imaging in the brain. These two cases may lead us to think that besides the Huntington Disease, the HSS is also an entity to be taken into consideration in a young patient with movement disorder, mental deterioration and progressive course.

Adolescent↗