A rare case of a boy with de novo microduplication at 5q35.2q35.3 from central Brazil.

Genomic disorders are genetic diseases that are caused by rearrangements of chromosomal material via deletions, duplications, and inversions of unique genomic segments at specific regions. Such rearrangements could result from recurrent non-allelic homologous recombination between low copy repeats. In cases where the breakpoints flank the low copy repeats, deletion of chromosomal segments is often followed by reciprocal duplication. Variations in genomic copy number manifest differently, with duplication and deletions of the same genomic region showing opposite phenotypes. Sotos syndrome is caused by alterations in the dosage of NSD1 on human chromosome 5 by either deletions or mutations, such as microdeletion of 5q35.2q35.3. In general, patients carrying reciprocal microduplication at 5q35.2q35.3 present no clinical phenotype or milder phenotype than do patients with microdeletion at the same locus. We report the first case of 5q35.2q35.3 microduplication encompassing NSD1 in a patient from central Brazil. We identified a genomic imbalance corresponding to a de novo 0.45 Mb microduplication at 5q35.2q35.3 by chromosomal microarray analysis and study of low-copy repeats. The proband had microduplication in the chromosomal region containing NSD1, which resulted in a Sotos syndrome reversed phenotype, and this duplication was associated with microcephaly, short stature, and developmental delay. Analysis of the genomic structure of the rearranged 5q35.2q35.3 chromosomal region revealed two major low-copy repeat families, which caused the recurrent rearrangements. Chromosomal microarray analysis is a potential tool to identify microrearrangements and guide medical diagnosis, which has to be followed by a non-directive genetic counseling approach to improve the quality of life of the patient.

CASE-REPORT Association between an ACAN gene variable number tandem repeat polymorphism and lumbar disc herniation: a case control study.

We investigated the association between an aggrecan gene (ACAN) polymorphism and lumbar disc herniation (LDH). This was a case-control study with quinquennial age and gender groups. The study comprised 119 men and women aged between 20 and 60 from Goiânia (Brazil). Of these, 39 were allocated to the case group (Ca) and 80 to the control group (Ct). We gathered sociodemographic and clinical data, and peripheral blood samples. DNA was isolated for genotyping the ACAN variable number tandem repeat (VNTR) via conventional polymerase chain reaction (PCR). Data were statistically analyzed using the chi-square test, multiple comparison analysis, the Student t-test, and odds ratios, with a level of significance set at 5% (P ≤ 0.05). The groups were homogenous in terms of sociodemographic, anthropometric, and life style variables. The allele score for the ACAN VNTR was significantly lower in volunteers with LDH; the A22 allele was significantly more prevalent in this same group; the Ca group presented greater frequency of short alleles A13-A25, whereas the Ct group presented a higher frequency of long alleles. However, this difference was not statistically significant. In both groups, the most common alleles were A28, A27, and A29, and the A26/A26 genotype was significantly more common in the Ca group. The results showed an association between short alleles and LDH among the investigated adults (Ca), corroborating the hypothesis that aggrecan with shorter repeat lengths can lead to a reduction in the physiological proteoglycan function of intervertebral disc hydration and, consequently, increased individual susceptibility to LDH.

Postnatal diagnosis of constitutive ring chromosome 13 using both conventional and molecular cytogenetic approaches.

We describe the first postnatal diagnosis of a child from Central Brazil with de novo cytogenetic alterations in 13q showing malformations of the brain, eyes, distal limbs, and genitourinary tract, and severe intellectual disability. The karyotype was a constitutive 46,XX,r(13)[77]/45,XX,-13[17]/46,XX,idic r(13)[6]. Interphase and metaphase fluorescence in situ hybridization analyses also showed the absence of 13qter and the presence of 13q14.3 in the cells with r(13), and chromosome microarray analysis detected a 15.39 Mb deletion in chromosome region 13q32.3-q34. This study is intended as the registry of a rare case of chromosomal rearrangement involving chromosome 13 in Central Brazil. Further studies are needed to define whether genetic haploinsufficiency is associated with each major 13q deletion anomaly.

[Anatomic variations of the coronary arteries]. / Contribuição ao estudo das variações anatômicas das artérias coronárias.

PURPOSE: To study the coronary arteries and their main branches showing the aspects of source, trajectory and anastomoses of these vessels at the subepicardial level. METHODS: The study was carried out on 110 adult human hearts, of both sexes, fixed in 10% formaldehyde solution. The pericardium was removed to expose the coronary arteries and their branches at the subepicardial level. RESULTS: In 38.18% of the cases the left coronary artery presented a trifurcation into anterior interventricular, circunflex and left marginal branches (35.70%) and into anterior interventricular, circunflex and lateral branches (64.30%). In 60% of the hearts examined, the left coronary artery presented a bifurcation into anterior interventricular and circunflex branches. In 1.82% of the cases these two branches arise directly from the aorta. An anastomosis, at the subepicardial level, between the anterior and posterior interventricular branches was observed in 56.36% of the hearts. In 88.18% the posterior interventricular branch arised from the right coronary artery, whereas in 11.82% this vessel arises from the circunflex branch. Anastomoses between the right coronary artery and the circunflex branch were found in 10% of the hearts (crux cordis). The dominance of the right coronary artery was present in 69.09% of the cases, of the left coronary artery in 11.82% and in 19.09% of the hearts had balanced distribution. CONCLUSION: The coronary arteries and their main branches present a great quantity of variations with regard to source, trajectory and anastomoses. This knowledge is important for the interpretation of coronary angiography and surgical myocardial revascularization.