Initial maternal meiotic I error leading to the formation of a maternal i(2q) and a paternal i(2p) in a healthy male

We report on the investigation of the parental origin and mode of formation of the two isochromosomes, i(2p) and i(2q), detected in a healthy adult male. Conventional cytogenetic analysis revealed the proband’s lack of structurally normal chromosomes 2, these being replaced by an i(2p) and an i(2q). Investigation of the parental origin of the isochromosomes revealed a paternal origin of the i(2p) chromosome and a maternal origin of the i(2q) chromosome. Thus, the formation of both isochromosomes, or at least of the paternal i(2p), appears to have occurred postzygotically. Interestingly, whilst a paternal isodisomy was observed for the entire 2p, maternal heterodisomy was detected for two segments of 2q, separated by a segment showing isodisomy. The results are indicative of an initial error (non-disjunction or i(2q) formation) concerning the maternal chromosomes 2 during meiosis I, which likely favored the subsequent mitotic recombination event resulting in the presence of two isochromosomes. To the best of our knowledge this is the first case of an initial meiotic error, followed by postzygotic trisomy rescue through the formation of isochromosomes, resulting in a normal phenotype. A prenatal detection, by cytogenetic and molecular analysis, of such chromosome abnormality would have led to the incorrect conclusion of a most likely poor prognosis for the fetus

Mutations in RAD21 disrupt regulation of apob in patients with chronic intestinal pseudo-obstruction

Background Aims Chronic intestinal pseudo-obstruction (CIPO) is characterized by severe intestinal dysmotility that mimics a mechanical subocclusion with no evidence of gut obstruction. We searched for genetic variants associated with CIPO to increase our understanding of its pathogenesis and to identify potential biomarkers. Methods We performed whole-exome sequencing of genomic DNA from patients with familial CIPO syndrome. Blood and lymphoblastoid cells were collected from patients and controls (individuals without CIPO); levels of messenger RNA (mRNA) and proteins were analyzed by quantitative reverse-transcription polymerase chain reaction, immunoblot, and mobility shift assays. Complementary DNAs were transfected into HEK293 cells. Expression of rad21 was suppressed in zebrafish embryos using a splice-blocking morpholino (rad21a). Gut tissues were collected and analyzed. Results We identified a homozygous mutation (p.622, encodes Ala>Thr) in RAD21 in patients from a consanguineous family with CIPO. Expression of RUNX1, a target of RAD21, was reduced in cells from patients with CIPO compared with controls. In zebrafish, suppression of rad21a reduced expression of runx1; this phenotype was corrected by injection of human RAD21 mRNA, but not with the mRNA from the mutated p.622 allele. rad21a Morpholino zebrafish had delayed intestinal transit and greatly reduced numbers of enteric neurons, similar to patients with CIPO. This defect was greater in zebrafish with suppressed expression of ret and rad21, indicating their interaction in the regulation of gut neurogenesis. The promoter region of APOB bound RAD21 but not RAD21 p.622 Ala>Thr; expression of wild-type RAD21 in HEK293 cells repressed expression of APOB, compared with control vector. The gut-specific isoform of APOB (APOB48) is overexpressed in sera from patients with CIPO who carry the RAD21 mutation. APOB48 also is overexpressed in sporadic CIPO in sera and gut biopsy specimens. Conclusions Some patients with CIPO carry mutations in RAD21 that disrupt the ability of its product to regulate genes such as RUNX1 and APOB. Reduced expression of rad21 in zebrafish, and dysregulation of these target genes, disrupts intestinal transit and the development of enteric neurons. © 2015 by the AGA Institute

Dislexia e ensino-aprendizagem de língua portuguesa : um estudo de caso

Monografia (graduação)—Universidade de Brasília, Instituto de Letras, 2013.Esta pesquisa trata da dislexia e do ensino-aprendizagem de Língua Portuguesa para disléxicos, com base em um estudo de caso com estudante disléxico da rede pública de ensino do Plano Piloto. Dentre as questões abordadas, estão as definições da dislexia, seus tipos e possíveis tratamentos, além da discussão do espaço que tal distúrbio de aprendizagem tem na educação, a sugestão de inclusão da dislexia na Educação Especial e, consequentemente, nas salas de recursos e a adequação da metodologia de ensino, baseada na exploração dos gêneros textuais e dos multiletramentos, dentro da perspectiva Sociointeracionista de Vygotsky e da proposta de professor libertador, de Paulo Freire

A case of mandibuloacral dysplasia presenting with features of scleroderma

juvenile scleroderma, a relatively rare condition, may be confused with a number of progeroid syndromes like Hutchinson-Gilford syndrome, Werner syndrome and Rothmund-Thomson syndrome. In this case report, we describe a 9-year-old boy who presented with scleroclactyly, acroosteolysis and scleroderma-like involvement of the skin over hands and feet, which suggested a diagnosis of juvenile scleroderma initially. However, absence of Raynaud's phenomenon, sparing of the skin other than hands and feet and negative serological studies did not support this diagnosis. On the basis of additional findings (micrognathia, dental malformation, a 'beaked nose', open cranial sutures and sparse hair), the patient was diagnosed as mandibuloacral dysplasia, a rare autosomal recessive disease. This case demonstrates that mandibuloacral dysplasia should be considered in the differential diagnosis of juvenile scleroderma in the presence of atypical features such as negative serological Studies, absence of Raynaud's phenomenon, sparse hair and micrognathia. (C) 2004 Blackwell Publishing Ltd

A case of progressive pseudorheumatoid arthropathy of 'childhood' with the diagnosis delayed to the fifth decade

Progressive pseudorheumatoid arthropathy of childhood (PPAC) is a rare single gene disorder which is frequently misdiagnosed as juvenile rheumatoid arthritis. It is characterised with arthralgia, joint contractures, bony swelling of metacarpophalangeal and interphalangeal joints and platyspondyly. Clinical and laboratory signs of joint inflammation such as synovitis, a high erythrocyte sedimentation rate and an elevated C-reactive protein level are usually absent. Although the disease begins early in life (usually between 3 and 8 years of age), the diagnosis may be delayed. In the present case report, we describe a male patient diagnosed with PPAC at the age of 46 years, although he had been exhibiting the typical radiological and clinical features of the disease since the age of 7 years

Rheological properties of blood in patients with chronic liver disease

We analyzed rheologic parameters, including erythrocyte rigidity (ER), whole blood and plasma viscosity, erythrocyte and platelet count, hemoglobin, hematocrit, mean corpuscular volume (MCV), fibrinogen, erythrocyte sedimentation rate (ESR), cholesterol, triglyceride, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very-low density lipoprotein (VLDL), and gamma globulin levels in 18 patients with chronic liver disease and 20 healthy volunteers. Fifteen patients had cryptogenic cirrhosis while 3 had chronic active hepatitis. ER and MCV was significantly higher in the patient group than the control group while whole blood and plasma viscosities were significantly lower. There were significant correlations between ER and blood and plasma viscosity, ER and MCV, plasma and blood viscosity, HDL and plasma viscosity and a negative correlation between ER and ESR. Our results demonstrate that erythrocytes become more rigid in chronic liver disease. We suggest that erythrocytes with increased rigidity can impair hepatic microvascular circulation and thus contribute to liver dysfunction

The effect of parental consanguinity on the clinical and laboratory findings of rheumatoid arthritis

Aims: We aimed to evaluate the frequency of consanguinity among the parents of patients with rheumatoid arthritis (RA) and the influence of parental consanguinity on several clinical and laboratory parameters which reflect the severity of the disease. Methods and patients: The study population consisted of 265 patients with RA which were divided into two groups with respect to the presence or absence of consanguinity between their parents. The frequency of parental consanguinity was compared with the general population. The two groups were compared with respect to family history of RA, the age of onset, the age at which RA was diagnosed, duration of the disease, the presence of rheumatoid nodules, vasculitis, serositis and the need for orthopaedic surgery, amyloidosis, the presence and level of rheumatoid factor and anti-cyclic citrullinated peptide antibodies, erosive changes on radiographs, and the need for anti-tumour necrosis factor therapy. Results: Twenty-one patients (8%) had parents who were consanguineous, which was not more frequent compared with the general population (14%). The mean age of disease onset and the mean age at which RA was diagnosed were lower in patients with parental consanguinity, although the difference was not statistically significant. The other clinical and laboratory parameters were also not different between the two groups. Conclusion: The present data suggests that parental consanguinity has no effect on disease severity, and the frequency of consanguinity is not increased among the parents of patients with RA. A possible exception is the earlier disease onset and age at diagnosis which needs to be confirmed by larger studies

Molecular analyses of the HGO gene mutations in Turkish alkaptonuria patients suggest that the R58fs mutation originated from Central Asia and was spread throughout Europe and Anatolia by human migrations

Alkaptonuria(AKU) is a rare metabolic disorder of phenylalanine catabolism that is inherited as an autosomal recessive trait. AKU is caused by loss-of-function mutations in the homogentisate 1,2-dioxygenase (HGO) gene. The deFIciency of homogentisate 1,2-dioxygenase activity causes homogentisic aciduria, ochronosis and arthritis. We present the first molecular study of the HGO gene in Turkish AKU patients. Seven unrelated AKU families from different regions in Turkey were analysed. Patients in three families were homozygous for the R58fs mutation; another three families were homozygous for the R225H mutation; and one family was homozygous for the G270R mutation. Analysis of nine intragenic HGO polymorphisms showed that the R58fs, R225H and G270R Turkish AKU mutations are associated with specific HGO haplotypes. The comparison with previously reported haplotypes associated with these mutations from other populations revealed that the R225H is a recurrentmutation in Turkey, whereas G270R most likely has a Slovak origin. Most interestingly, these analyses showed that the Turkish R58fs mutation shares an HGO haplotype with the R58fs mutation found in Finland, Slovakia and India, suggesting that R58fs is an old AKU mutation that probably originated in central Asia and spread throughout Europe and Anatolia during human migrations