[Chromosomal abnormalities in malignant hematologic diseases]

The inclusion of cytogenetic studies in the protocol study of patients with hematological malignant diseases is a very important contribution because these results contribute to establish better precision of diagnosis, prognostic and suggest adequate therapeutic management precociously. The Karyotypes of 200 patients between ages of 2 and 84 years, 56/200 acute lymphoblastic leukemia (ALL), 55/200 acute myeloid leukemia (AML), 63/200 chronic myeloid leukemia (CML), 20/200 myelodysplastic syndrome (MDS), and 6/200 chronic lymphocytic leukemia, (CLL), are analyzed. Certain differences were noted. In ALL, hyperdiploidy was the chromosomal abnormality more frequently observed and no cases of Ph+ chromosome were reported; with respect to AML, the autosomal monosomy and trisomy were the most frequent findings. MDS reports only one case with 5q deletion, 10% of patients presented trisomy 14, rarely reported. CML do no report any case with double Ph+ and only one case with i(17q); nevertheless, one case with 21q deletion was found, which is an unreported anomaly. CLL did not present any case with trisomy 12. These findings are discussed in the context of geographical heterogeneity of chromosomal abnormalities in leukemia, and emphasize the importance of continued epidemiological studies.

[Cytogenetic findings in ductal carcinoma of the breast]

Breast cancer in women is an important medical problem with public health and social implications. In spite of its great clinical importance, little is known about the cytogenetic features of breast carcinomas. Chromosomal abnormalities in some malignant tumors have been used for diagnosis and prognosis or for localizing genes involved in the pathology malignancies. In this report, we present the chromosomal abnormalities found in 32 primary breast ductal carcinomas. The tumor samples were studied using the technique for short-term culturing and cytogenetic analysis with G-banding. Only one tumor with normal karyotype was observed. Thirty one (99%) of the tumors had chromosomal abnormalities including 21 (65.6%) in which chromosome 1 was involved (trisomy, monosomy or structural abnormalities of the type t(1q;2p) and del(1q42). Other recurrent anomalies such as del(12p); del 4(p); +7; +8; -7; -3; were observed. The significance of these findings and their role in tumorogenesis will become more evident with close follow-up of women who have tumors with an abnormal karyotype.

[Pulmonary atresia with intact interventricular septum. Report of a case diagnosed by fetal echocardiography]

Pulmonary atresia with intact ventricular septum (PA/IVS) is a rare cardiac congenital malformation involving the right ventricle (RV) in which the communication through pulmonary valve, is absent. A case of a congenital heart disease (CHD) consisting of pulmonary atresia with intact ventricular septum (PA/IVS) and small right ventricle (RV) or type I of Greenwold, coming from a twin pregnancy in which the other was an inutero dead fetus, is reported. Although the case was referred after the death of one of the fetuses, the prenatal diagnosis was made by the use of echocardiographic studies and confirmed by anatomopathology of the still-born fetus with the CHD. The very useful echocardiographic prenatal diagnosis and surgical therapeutical options are emphasized and discussed.

[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.

[Prenatal diagnosis. I: Prenatal diagnosis program at the Medical Genetics Unit of the Universidad de Zulia, Maracaibo, Venezuela]

The Prenatal Diagnosis Program of the Medical Genetic Unit of University of Zulia has the following objectives: Identification of Genetic Risk Factors (GRF) in those couples who attend to the Prenatal Genetic Clinic, application of different prenatal diagnostic procedures (PDP), and providing adequate genetic counseling. The goal of this paper is to show preliminary results obtained between January 1993 and December 1996. Three hundred and twenty one pregnant women were analyzed by determining the GRF and taking into account the genetic clinical history. The GRF analyzed were: Advanced maternal age (AMA), congenital malformation history (CMH), previous child with chromosomic anomalies (PCCA), defects of neural tube history (DNTH), congenital heart disease history (CHDH), any parent carrier of chromosomic anomaly (PCA), habitual abortion (HA), abnormal fetal echography (AFE), altered maternal serum levels of alpha-feto-protein (AMSAFP) and OTHERS: exposure to teratogenic agents, history of Mendelian diseases, maternal systemic diseases and anxiety in the mother or in her partner. The PDP was designed according to the GRF, which included fetal echography (FE), fetal echocardiography (FEc), amniocentesis (AMN), chordocentesis (CCT) and AMSAFP. Results showed that 58.4% of the expectant mothers asked for counseling during the 2nd trimester, 70% of the total showed only one GRF, and AMA was the most frequent GRF found (40.3%), followed by PCCA, AFE, CHDH, HA, DNTH, PCA, and OTHERS in that order. The specific PDP applied to the identified GRF allowed a health evaluation of the fetus. The GRF identification gave the opportunity of establishing a Prenatal Diagnostic Program producing a response to the couple's needs and showed the utility of an integral and multidisciplinary management directed to any expecting mother in order to identify any high GRF.

[Prenatal molecular diagnosis of cystic fibrosis. Report of 3 cases]

Cystic Fibrosis (CF) is a severe and relatively common autosomic recessive disease caused by a variety of mutations in the CFTR gene. The most frequent mutation worldwide, consists of the deletion of the phenylalanine codon at position 508 (delta F508). Here we report the first cases of prenatal diagnosis of CF by DNA analysis in couples at risk in Venezuela. The study focused on the detection of delta F508 alleles analyzing DNA recovered directly from amniocytes or from their cultures, using the polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis. Two of three fetuses resulted homozygotic for the delta F508 allele and the third one turned out to be a delta F508 carrier. This information sustained the genetic counseling of the couples and allowed them to take objective reproductive decisions, a direct consequence of the availability of gene analysis at the DNA level.

[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.

[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.

[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.

[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.

[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.

[Epidemiology of congenital malformations at the Hospital Pedro García Clara, Ciudad Ojeda, Venezuela]

Results from an epidemiological study of congenital malformations (CM) realized at Pedro Garcia Clara Hospital from march 1989 to december 1992 are presented. Malformation was defined as all external or internal morphological defects that could be clinically diagnosed at birth. In all births, incidence and type of CM, birth condition, sex, weight, number of pregnancies and maternal ages were analyzed. Moreover, in live births from march 1989 to august 1991, were analyzed: the type of childbirth presentation, maternal residence place, paternal age, maternal and paternal occupation and school education, parental consaguinity, previous spontaneous abortions, other malformed in the family and exposition to physical agents, medicaments, vaccines, acute and chronical diseases and vaginal bleeding in the first trimester of pregnancy. The control group were children born during the same day and sex matched as the malformed children. The incidence of CM was 23.4 per 1000 total births. Most frequent malformations were principally minor or feasible of satisfactory treatment. Major malformations were Central Nervous System anomalies, specially, neural tube deffects and Down syndrome. Only maternal age, type of childbirth, other malformed members in the family and medicaments exposition were statistically significant. Our results confirm the importance and utility of CM epidemiology monitoring.