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Biomedical subjects

J Sánchez-Corona

Publications and source records attributed to J Sánchez-Corona.

At least 19 recordsLinked to original sources

Constitutional duplication 11q23 de novo involving the MLL gene.

We report a child with mental retardation, brain anomalies and congenital heart defect. His karyotype, after G-banding and FISH with a whole chromosome probe for chromosome 11 and a locus-specific probe for the MLL gene, was 46,XY,dup(11)(q23q23).ish dup(11)(q23q23)(wcp11+, MLL++) de novo; i.e., he had a pure partial 11q23 duplication. Clinical and cytogenetic findings of the present case were compared with the 7 previously reported cases with pure partial trisomy 11q; in 6/8 cases the region 11q23 was involved. We conclude that the scarce number of cases and their heterogeneity do not allow to establish a reliable genotype-phenotype correlation.

Brain↗

Association analysis of the Gln223Arg polymorphism in the human leptin receptor gene, and traits related to obesity in Mexican adolescents.

Polymorphisms of leptin receptor (LEPR) may contribute to a common form of obesity and, as a consequence, obesity-related diseases. We evaluated the potential role of genetic variation at the LEPR gene in heart sympathetic activity and other traits related to obesity in Mexican adolescents. Adolescents aged between 12 and 17 years, with steady body weight for the last 3 months were included. We evaluated anthropometric measurements, blood pressure, seric glucose, insulin, leptin levels, heart sympathetic activity (by electrocardiograph monitoring at rest), and the Gln223Arg and Pro1019Pro LEPR polymorphisms in each subject. In total, 103 adolescents (55 obese and 48 nonobese) were included. The group of obese adolescents showed higher sympathetic activity, blood pressure, glucose, insulin, and leptin levels. The genotype frequencies for the two polymorphisms were found to be in Hardy-Weinberg equilibrium. There was no difference in the genotype frequencies for Gln223Arg or Pro1019Pro polymorphisms between obese and nonobese adolescents. However, there was a higher prevalence of Gln223 allele among subjects with higher insulin levels (0.72 vs 0.57; P = 0.04 for adolescents with insulin levels higher and lower than 100 pmol/l, respectively). According to Gln223Arg polymorphism, those with Gln allele (Gln/Gln and Gln/Arg) had higher heart sympathetic activity, body fat percentage, and leptin levels. To conclude, our results support the hypothesis that Gln223Arg polymorphism of LEPR in Mexican adolescents is associated with haemodynamic and metabolic disturbances related to obesity.

Adolescent↗

Zimmermann-Laband syndrome: further clinical delineation.

Zimmermann-Laband syndrome (ZLS) is an autosomal dominant disorder characterized by gingival fibromatosis, absent or dysplastic distal phalanges, vertebral defects, hepatosplenomegaly, hypertrichosis and sometimes mental retardation. We describe two unrelated patients, a girl aged 9 years and a boy 11 months whose clinical and radiological findings permit us to diagnose the ZLS. Body overgrowth, present in both patients, was identified as a main clinical feature not previously reported as well as the presence in neuroimaging studies of a cavernous hemangioma on the frontal and the left cerebellar regions in the boy. The girl also presented important radiological characteristics such as broad medulary canals and metaphyses of long bones, thin cortices, broad ribs, accelerated skeletal maturation as well as high intelligence level. A wide clinical spectrum in ZLS is also considered.

Child↗

Polymorphisms in candidate genes for type 2 diabetes mellitus in a Mexican population with metabolic syndrome findings.

The metabolic or insulin resistance syndrome, characterized by hypertension, dyslipidemia, glucose intolerance and hyperinsulinemia, may have genetic determinants. The insulin gene (INS), insulin receptor gene (INSR) and insulin receptor substrate 1 gene (IRS1) have been proposed as candidate genes. We examined eight polymorphisms in these genes in 163 individuals from Yucatan, Mexico; this population has a high prevalence of obesity, type 2 diabetes mellitus and dyslipidemia. Subjects were evaluated for body mass index (BMI) and blood pressure. Blood samples were collected to determine glucose, insulin, triglycerides and cholesterol levels, as well as for DNA isolation. Restriction fragment length polymorphisms in INS, INSR and IRS1 were identified by polymerase chain reaction and digestion with selected restriction enzymes. Among the eight polymorphisms analyzed, the PstI polymorphism in INS was significantly associated with hypertriglyceridemia and with the presence of at least one abnormality related to the metabolic syndrome (P=0.007 and 0.004, respectively). The MaeIII polymorphism in INS was associated with fasting hyperinsulinemia (P=0.045). In multilocus analyses including both INS polymorphisms, significant associations were seen with hypertriglyceridemia (P=0.006), hypercholesterolemia (P=0.031) and with presence of at least one metabolic abnormality (P=0.009). None of the polymorphisms in INSR or IRS1 was associated with any of these traits. These findings suggest that the insulin gene may be an important determinant of metabolic syndrome, and particularly of dyslipidemia, in this population.

Adolescent↗

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome.

Complete achromatopsia associated with skeletal anomalies: a new autosomal recessive syndrome: Achromatopsia or rod monochromatism is the complete absence of color discrimination, with an estimated frequency of 1 in 100,000. To date the McKusick Catalogue includes more than 10 entities related to Achromatopsia. This paper describes four Mexican sibs with a stationary rod monochromatism, associated with long fingers and toes, hypothenar and thenar hypoplasia and pes planus, suggesting a new genetic entity probably inherited in an autosomal recessive mode.

Adolescent↗

Myhre syndrome: first female case.

A 15 year old girl with the Myhre type growth-mental retardation syndrome is described. This is the first female case reported in the literature. The inheritance pattern of this condition is not clear.

Abnormalities, Multiple↗

A variant example of familial Floating-Harbor syndrome?

The Floating-Harbor syndrome (FHS) is clinically characterized by short stature, retarded speech development, delayed bone age, typical facies, bulbous nose, wide columella, thin lips. Four cases with celiac disease have been described previously. In two other cases, autosomal dominant inheritance has been suggested. We describe a boy aged 2 years 11 months with clinical features of FHS and celiac disease. His mother also presents minor phenotypical characteristics, suggesting that the present observation corresponds to a variant example of familial FHS.

Age Determination by Skeleton↗

Association analysis of polymorphisms in the interleukin-4 receptor (alpha) gene with atopic asthma in patients from western Mexico.

We undertook an association analysis between the ile50val, glu375ala, cys406arg, and ser761pro polymorphisms of the IL-4Ralpha gene and atopic asthma, total IgE levels and IL-4 serum levels in a population from western Mexico. We found that the ser761pro polymorphism was monomorphic for ser761, while there was no association between any of the other polymorphisms and the three phenotypes analysed.

Amino Acid Substitution↗

Molecular identification of 7 human papillomavirus types in recurrent respiratory papillomatosis.

BACKGROUND: Recurrent respiratory papillomatosis (RRP) is the most frequent benign neoplasm in childhood; it originates as a mild dysphonia and results in asphyxia. The RRP has been associated with an infection caused by human papillomavirus (HPV), mainly types 6 and 11, the latter being associated with more severe RRP. OBJECTIVES: To analyze the frequency of the association of RRP with the HPV types in our juvenile population and to classify it according to severity. DESIGN: Observational descriptive trial. MATERIALS AND METHODS: Forty-seven samples of paraffin-embedded papillomas, from 26 female and 21 male children (age range, 2 weeks to 17 years) were analyzed. DNA was isolated and a 188-base pair fragment was amplified from a consensus sequence in the E1 open reading frame of several HPVs by polymerase chain reaction. The corresponding band was recovered and reamplified. The fragment was digested with the restriction enzyme RsaI. The digestion products were compared with patterns of molecular weight markers for viral type identification. The patients' clinical records were reviewed, and RRP was classified as mild or aggressive. RESULTS: The presence of HPV types 6, 11, 16, 31, 33, 35, or 39 was confirmed in all the cases with different combinations. The chi(2) test showed no significant differences in clinical aggressiveness among the viral types. A logistic regression analysis demonstrated no association between clinical aggressiveness and any viral type or viral combination. CONCLUSION: These results show that RRP is caused by infection with HPV types 6 and 11 in addition to many other types, with no relationship between HPV type and clinical severity.

Adolescent↗

An extra idic(21)(q22.1) in a child with some features of Down's syndrome.

A 30-month-old boy with mental retardation, hypotonia, joint hyperlaxity, Brushfield spots, open mouth, distal axial triradius t", and ulnar loops on both forefingers was found to have a 47,XY, + psu idic(21)(q22.1).ish psu idic(21)(q22.1)(D13Z1/D21Z1 + + ,ETS2-) karyotype. The patient's phenotype, with only some Down's syndrome (DS) features, is probably related to his disomy for most or all of the critical region 21q22.2 q22.3 and agrees with the current notion that certain DS features may also result from 21q proximal duplications. The phenotypical comparison with 2 other patients with a similar extra idic(21) reveals some discrepancies, which may be related to the inherent clinical variability of similar imbalances: yet, a real difference between the tetrasomic segments cannot be excluded. Noticeably, all 3 patients with 21q proximal tetrasomy did not have cardiac defect and exhibited none or just one out of the five other DS phenotypic features attributed to a single gene or cluster on distal 21q22.

Adult↗

Determination of diesel genotoxicity in firebreathers by micronuclei and nuclear abnormalities in buccal mucosa.

Diesel or its derivatives could have aneuploidogenic and/or clastogenic activity. Hence, the genotoxicity of diesel gases has been studied, considering exposure to them as potentially carcinogenic. The results obtained by different authors suggest the need to know the effects of direct and chronic exposure to diesel in humans, as in the case of the street workers called 'firebreathers' who fill their buccal cavity with diesel and then spread it to a burning torch many times during the day in order to give a 'dragon show' for 5 h a day and 6 days a week. The buccal samples of eight firebreathers were collected, processed and scored according to the criterion established by Tolbert et al., 1992 and then compared with positive and negative control groups. The results revealed that diesel was not micronucleogenic although it induces some nuclear abnormalities.

Adult↗

Induction of micronuclei in the domestic cat (Felis domesticus) peripheral blood by colchicine and cytosine-arabinoside.

One advantage of bioassays over other kinds of tests is the processing or metabolism of the compound by the organism. In a previous work, in which we reported the number of micronucleated erythrocytes (MNE) in the peripheral blood of 35 species, the cat was one of the species with the highest number of micronuclei (MN). Cats have a low level of circulating polychromatic erythrocytes (PCE), i.e. 0.05%, which is much lower than in the laboratory mouse, but higher than in species such as cows, donkeys, sheep, goats and horses. Thus, MN were scored in total blood erythrocytes. In the present work, we assess the cat as a test system for MN induction. Three doses of a colchicine-cytosine arabinoside mixture were administered to young cats during 4 days; then, the numbers of MNE in blood collected before the first injection and 48 and 96 h later were compared. The number of MNE increased with time, reaching the highest values in the samples taken 96 h after the administration of the micronucleogenic agents.

Animals↗

Clinical, morphological and biochemical features in the familial articular hypermobility syndrome (FAHS): a family study.

A female with clinical features of familial articular hypermobility syndrome (FAHS) and her family were studied. The subject showed generalized hypermobility, except for a painful shoulder which presented functional limitation with a diagnosis of painful shoulder syndrome. Biochemical studies demonstrated that collagen and glycosaminoglycans (GAGs) contents from skin biopsies of the subject and her family were almost normal. Nevertheless, the densitometric analysis of electrophoretic patterns showed differences in the relative proportions of their collagenous components. They were characterized by changes in type I and III collagens and the presence of type V collagen, in the subject, her father and brother. Also, they presented changes in the types of GAGs, when compared with those of normal skin. Morphological studies revealed a general disorganization of dermal components, a loose collagen network characterized by thick bundles. Also, besides cellular elements, the presence of an abundant darkly staining material was observed. Biochemical and morphological findings permit us to suggest a connective tissue defect, initially described in the FAHS, otherwise known as Ehlers Danlos syndrome (EDS) type XI.

Adult↗

Molecular analysis of northwestern Mexican patients with cystic fibrosis: screening of 10 known mutations. Mutations in brief no. 185. Online.

We have analyzed 45 unrelated Northwestern Mexican patients with Cystic Fibrosis for 10 known CF mutations (DF508, G542X, G551D. R553X, W1282X, NI303K, R334W, R347H, S549R, and R1162X). Screening was performed on exons 7, 10, 11, 19, 20 and 21 using standard methods such as polymerase chain reactions, reverse dot blot hybridization (non-radioactive), and restriction enzyme digestion. The analysis for these ten mutations permitted the identification of only two mutations in 37.7% of CF chromosomes in this sample. The major mutation, delta F508, accounts for 34.4% of CF chromosomes. Of the 45 CF patients 9 (20.0%) were homozygous delta F508 deletion, 11 (24.4%) were heterozygous for the delta F508 mutation and an unknown mutation. One additional mutation G542X was also found in 3 chromosomes in our population (3.3%). Two patients were documented to be a compound heterozygote for DF508/G542X, and other one heterozygous for G542X and an unknown mutation. Therefore 62.2% of chromosomes remain uncharacterized.

Cystic Fibrosis↗

Congenital hypertrichosis, osteochondrodysplasia, and cardiomegaly: further delineation of a new genetic syndrome.

The hypertrichosis and osteochondrodysplasia syndrome is a rare entity with clinical findings including macrosomia at birth cardiomegaly. Autosomal recessive inheritance is presumed based on the report of two affected sibs born to healthy parents. Here we report on four new patients with their follow-up data, as well as on one of the four cases from the original report. Comparison of all eight cases indicates that they share 50% of clinical and radiological changes. This report contributes to the further delineation of this newly recognized syndrome.

Abnormalities, Multiple↗

Mucopolysaccharidoses type II: enzymatic activity and quantitative and qualitative studies of urinary glycosaminoglycans in five patients.

Five patients presenting Hunter's syndrome were biochemically studied. Quantification of urinary glycosaminoglycans (GAGs), electrophoretic characterization and correlation with enzymatic activity in leucocytes were carried out. In all cases, urinary GAGs/creatinine ratio was increased. Electrophoresis revealed the presence of heparan sulfate (HS) and dermatan sulfate (DS) in four cases (80%), but in the remaining patient, only DS was present. In all patients, deficient enzymatic activity was demonstrated. These results show evidences of biochemical differences in this syndrome.

Child↗