Maria Betânia Pereira Toralles

A clinical study of 77 patients with mucopolysaccharidosis type II

Aim: This study aims to assess the clinical features of 77 South American patients (73 Brazilian) with mucopolysaccharidosis type II (MPS II).

Gender dysphoria associated with disorders of sex development

Disorders of sex development (DSDs) are estimated to be prevalent in 0.1–2% of the global population, although these figures are unlikely to adequately represent non-white patients as they are largely based on studies performed in Europe and the USA. Possible causes of DSDs include disruptions to gene expression and regulation—processes that are considered essential for the development of testes and ovaries in the embryo. Gender dysphoria generally affects between 8.5–20% of individuals with DSDs, depending on the type of DSD. Patients with simple virilizing congenital adrenal hyperplasia (CAH), as well as those with CAH and severe virilization, are less likely to have psychosexual disorders than patients with other types of DSD. Early surgery seems to be a safe option for most of these patients. Male sex assignment is an appropriate alternative in patients with Prader IV or V DSDs. Patients with 5α-reductase 2 (5α-RD2) and 17β-hydroxysteroid dehydrogenase 3 (17β-HSD3) deficiencies exhibit the highest rates of gender dysphoria (incidence of up to 63%). Disorders such as ovotesticular DSD and mixed gonadal dysgenesis are relatively rare and it can be difficult to conclusively evaluate patients with these conditions. For all DSDs, it is important that investigators and authors conform to the same nomenclature and definitions to ensure that data can be reliably analysed.

Immunogenetics and infectious diseases: special reference to the mayor histocompatibility complex.

Many studies have tried to identify genetic markers for infectious diseases, some of them have focused on human leukocyte antigens (HLA). The products of HLA genes interact with surface-specific receptors of T lymphocytes, resulting in activation of the hosts immune response. Association of bacterial, viral, parasitic and fungal infections with the hosts HLA has been widely investigated. The type and strength of this association differs among distinct populations, as well as among racial and/or ethnic groups. The new molecular methods for the identification of the HLA alleles, and the resulting new nomenclature, have contributed to a better understanding of this system. Unfortunately, this information has not been adequately transmitted to clinicians, which hampers the understanding of the association between the HLA system and diseases. We revised relevant studies on the association of HLA genes with infectious diseases, demonstrating their importance in the pathogenic mechanisms, through increased susceptibility or protection against infections and their complications.

Huntington disease and Huntington disease-like in a case series from Brazil

The aim of this study was to identify the relative frequency of Huntingtons disease (HD) and HD‐like (HDL) disorders HDL1, HDL2, spinocerebellar ataxia type 2 (SCA2), SCA17, dentatorubral‐pallidoluysian degeneration (DRPLA), benign hereditary chorea, neuroferritinopathy and chorea‐acanthocytosis (CHAC), in a series of Brazilian families. Patients were recruited in seven centers if they or their relatives presented at least chorea, besides other findings. Molecular studies of HTT, ATXN2, TBP, ATN1, JPH3, FTL, NKX2‐1/TITF1 and VPS13A genes were performed. A total of 104 families were ascertained from 2001 to 2012: 71 families from South, 25 from Southeast and 8 from Northeast Brazil. There were 93 HD, 4 HDL2 and 1 SCA2 families. Eleven of 104 index cases did not have a family history: 10 with HD. Clinical characteristics were similar between HD and non‐HD cases. In HD, the median expanded (CAG)n (range) was 44 (40–81) units; R2 between expanded HTT and age‐at‐onset (AO) was 0.55 (p = 0.0001, Pearson). HDL2 was found in Rio de Janeiro (2 of 9 families) and Rio Grande do Sul states (2 of 68 families). We detected HD in 89.4%, HDL2 in 3.8% and SCA2 in 1% of 104 Brazilian families. There were no cases of HDL1, SCA17, DRPLA, neuroferritinopathy, benign hereditary chorea or CHAC. Only six families (5.8%) remained without diagnosis.

Exposição ambiental a interferentes endócrinos com atividade estrogênica e sua associação com distúrbios puberais em crianças

Endocrine disruptors are exogenous substances with adverse health effects in intact organisms or their progeny, secondary to changes in endocrine function. Recent years have witnessed constant reports of environmental factors with hormone-like effects causing pubertal or reproductive abnormalities in animals. The few cases proven to be associated with pubertal disorders in humans have been related to accidental exposure. Nevertheless, pediatricians and parents recommend suspending all possible estrogen-contaminated food, especially meat (poultry, beef) and soy products, when the child presents with a pubertal disorder. These recommendations, if not scientifically sound, may have deleterious consequences by eliminating sources of dietary protein and possibly delaying the investigation of other potential and treatable causes. On the other hand, not investigating potential side effects of these products could have similar harmful effects. The current article describes the main endocrine disruptors associated with pubertal disorders in humans and concludes that except for accidental exposure to high doses, more research is needed on the effects of chronic and low-dose exposures in altering human pubertal development.

Distribuição e freqüência de alelos e haplotipos HLA em brasileiros com diabetes melito tipo 1

The genetic predisposition to type 1 diabetes (DM1) is associated with genes of the human leukocyte antigen (HLA) system, specially the HLA-DR and -DQ. In Caucasians, the HLA-DR3 and -DR4 antigens are associated with susceptibility and the -DR2, with protection. In Brazil, a country with a large miscegenation of Europeans Caucasians, Native Amerindians and African Blacks, the genetic basis of DM1 has not been adequately studied. The aim of this paper is to present a critical review of articles indexed in the MEDLINE and LILACS-BIREME data basis about the association of HLA with DM1 in Brazilians. Eight papers, all of them from the Southeast region, were found. Immunogenetic susceptibility to DM1 in Brazilians was associated with HLA-DRB1*03, -DRB*04, -DQB1*0201, -DQB1*0302 alleles, and protection against DM1 was associated with HLA-DQB1*0602, -DQB1*0301 alleles and -DR2 and -DR7 antigens. Since the Brazilian population is not racially homogeneous, it is not possible to extrapolate studies from a single region to the remaining of the country. It is necessary to study populations from different regions to identify new associations or to strengthen associations with the ones already identified. This knowledge will contribute to future prophylactic or therapeutic interventions in the group of Brazilians at risk of developing DM1.

Bisphosphonates: Pharmacokinetics, bioavailability, mechanisms of action, clinical applications in children, and effects on tooth development

Bisphosphonates (BPs) avidly bind to calcium crystals and inhibit osteoclastic bone resorption, making them useful for treatment of skeletal disorders such as osteoporosis, Pagets disease, osteogenesis imperfecta and metastatic bone diseases. BPs therapeutically act by causing toxic effects on osteoclasts or interfering with specific intracellular pathways in those cells. BPs that possess nitrogen in their composition are called nitrogen-containing BPs (NBPs) and include alendronate, pamidronate, risedronate, ibandronate, and zoledronate. Simple BPs or non-NBPs do not have nitrogen in their composition, include etiodronate and clodronate, and were the first to be tested in animals and clinically used. Because BPs may be administered to pregnant women or children during deciduous and permanent teeth development, it is expected that they might disturb tooth eruption and development. A review of current literature on pharmacokinetics, bioavailability, mechanisms of action, and clinical applications of BPs in children, and their effects on tooth eruption and development is presented.

Germline mutations in BRCA1, BRCA2, CHEK2 and TP53 in patients at high-risk for HBOC: characterizing a Northeast Brazilian Population.

Considering the importance of BRCA1, BRCA2, CHEK2 and TP53 in the development of hereditary early-onset breast and ovarian cancer and that the genetic susceptibility profile of the Northeast population from Brazil has never been analyzed, this study aimed to verify the frequency of mutations of clinical significance in these genes in high-risk hereditary breast and ovarian cancer (HBOC) syndrome patients from that region. DNA samples from 106 high-risk unrelated patients mostly from Bahia, the biggest state in the Northeast region, were analyzed. These patients underwent full BRCA1 gene sequencing, screening for common founder mutations in the BRCA2, CHEK2 and TP53 genes and genetic ancestry analysis with nine ancestry informative markers. The positive results were confirmed by two sequencing reactions. Three mutations of clinical significance were found: BRCA1 p.R71G (4.71%), 3450del4 (3.77%) and TP53 p.R337H (0.94%). The genetic ancestry analysis showed a high European ancestry contribution (62.2%) as well as considerable African (31.2%) and Amerindian (6.6%) ancestry contributions (r2=0.991); this degree of heterogeneity was also significant in the population structure analysis (r=0.604). This population is highly admixed with a different spectrum of genetic susceptibility, with the Galician founder mutation BRCA1 p.R71G accounting for 50% of all identified mutations in high-risk HBOC patients. TP53 p.R337H was also significantly frequent; thus, the combined screening of BRCA1/2 and TP53 should be offered to high-risk HBOC patients from Northeast Brazil.

Antígenos de histocompatibilidade humanos e dermatologia: da pesquisa para a prática clínica

The participation of the human histocompatibility system (HLA: human leukocyte antigens) in the pathogenesis of autoimmune diseases is well known. Situated on the short arm of chromosome 6, the HLA system is very polymorphic and has the capacity to confer susceptibility or resistance to different diseases. In Dermatology, this system has an important participation in the pathogenesis and natural course of various diseases. The strength and type of association differ with conditions and sometimes with the ethnic-racial group studied. The discovery of molecular methods to typify HLA alleles and recent updates in its nomenclature has contributed to a better understanding of this system. Unfortunately, this information has not been adequately transmitted in the literature, hindering identification of the association of the HLA with skin diseases. In this review, some aspects of the HLA system are discussed, such as methods of detection, nomenclature and association with vitiligo, pemphigus, psoriasis, lupus erythematosus, scabies, cutaneous Leishmaniasis, leprosy, paracoccidiodomycosis and atopic dermatitis.

Proteus syndrome: Clinical diagnosis of a series of cases

Objectives: This paper describes the clinical diagnosis of Proteus syndrome (PS) in children referred for evaluation of asymmetric disproportionate overgrowth. Materials and Methods: Retrospective, descriptive, cross-sectional study conducted from January 1998 to December 2010. Results: During the study period, 2011 new patients were evaluated. Thirteen (0.65%) patients presented features suggestive of PS. These patients were formally evaluated based on the revised diagnostic criteria proposed by Biesecker. The mean age was 6.92 ± 5.1 years. Ten patients (76.9%) were females. All subjects had asymmetric disproportionate overgrowth. Other dysmorphic features were as follows: macrodactily (84.6%); linear epidermal nevus (41.6%); hemangioma (30.7%); and lipoma (23%). Six patients fulfilled the diagnostic criteria for PS. Conclusions: The diagnostic rate of only 46.1% of patients with PS confirms the diagnostic difficulties and the need for continuous monitoring and periodic review of these patients since the clinical manifestations of this syndrome become more evident with aging. Molecular tests may help the differential diagnosis of Proteus syndrome when they became commercially available.