INTRODUÇÃO: As alterações cromossômicas são a primeira suspeita etiológica em indivíduos com múltiplas anomalias congênitas, atraso de desenvolvimento neuropsicomotor e/ou deficiência cognitiva. Verifica-se que em alguns pacientes esse fenótipo está associado a alterações pigmentares como as manchas cutâneas. Porém, nem sempre o resultado do cariótipo em sangue periférico para esses pacientes revela alterações cromossômicas. Dessa forma, a análise cromossômica de outro tecido, como a cultura e cariotipagem dos fibroblastos da pele, torna-se importante para verificar a ocorrência de mosaicismo oculto que poderia explicar o fenótipo clínico. OBJETIVOS: Padronizar e implantar um protocolo para cultura de fibroblastos de pele humana, oriunda de manchas cutâneas de pacientes com atraso de desenvolvimento neuropsicomotor e/ou malformações. Estabelecer o método de cariotipagem molecular de fibroblastos em tecido epitelial e realizar a correlação com o fenótipo. MÉTODOS: Os pacientes foram provenientes do ambulatório de Genética do Instituto da Criança do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (ICR-HCFMUSP). Foram realizados cariótipos de fibroblastos de pele de 15 pacientes com cariótipo de sangue periférico normal, portadores de manchas cutâneas associadas ao atraso de desenvolvimento neuropsicomotor e/ou malformações. A análise citogenética dos fibroblastos foi feita a partir de biópsia cutânea das manchas, seguida dos seguintes procedimentos: cultura de fibroblastos, processamento, cariotipagem por bandamento G e análise citogenética molecular. RESULTADOS: Dentre os 15 casos estudados, 8 apresentaram isocromosomo de 12p (síndrome de Pallister-Killian), 1 apresentou um mosaicismo sexual atípico e os outros 6 apresentaram resultado normal. CONCLUSÃO: A análise cromossômica de fibroblastos foi imprescindível para o diagnóstico de pacientes com manchas cutâneas associadas à múltiplas anomalias congênitas, atraso de desenvolvimento neuropsicomotor e/ou deficiência cognitiva. A abordagem diagnóstica adequada é fundamental para conduzir o tratamento de forma apropriada e para definir o prognóstico desses pacientes, sendo também imprescindível para a realização do aconselhamento genético / INTRODUCTION: Chromosomal aberrations are the first suspected etiology in individuals with multiple congenital anomalies, developmental delay and/or intellectual disability. This phenotype is sometimes associated with pigmentary skin anomalies. However, in some cases the peripheral blood cells karyotype is normal. Therefore, the cytogenetic analysis of other tissues such as culture and karyotyping of skin fibroblasts is important to verify the occurrence of cryptic mosaicism that may explain the clinical phenotype. OBJECTIVES: To standardize and set a protocol for culture of human skin fibroblasts. To perform molecular karyotyping of fibroblasts and establish the correlation with phenotype. METHODS: Patients were recruited from the outpatient clinic of the Genetics Unit of Instituto da Criança do Hospital das Clínicas d Faculdade de Medicina da Universidade de São Paulo (ICR-HCFMUSP). The karyotypes of skin fibroblasts were performed in 15 patients with normal blood karyotype, presenting with pigmentary skin anomalies associated with developmental delay and/or malformations. The cytogenetic analysis of fibroblasts was made from skin biopsy of the spots, followed by fibroblast culture, processing, karyotyping by G-banding analysis and molecular cytogenetics. RESULTS: Among the 15 cases studied, 8 showed isochromosome 12p (Pallister-Killian syndrome), 1 had atypical sexual mosaicism and the other 6 had normal results. CONCLUSION: The cytogenetic analysis of skin fibroblasts is crucial for the diagnosis of patients with pigmentary skin anomalies associated with developmental delay and/or malformations. The proper diagnosis is fundamental for the appropriate treatment, to define prognosis for these patients and essential for the genetic counselling

Object Rupture of intracranial arteriovenous malformations is a leading cause of stroke in children and young adults. Treatment options include surgery and highly focused radiation (stereotactic radiosurgery). For large and deep seated lesions, the risks of surgery may be prohibitively high, while radiosurgery has a disappointingly low efficacy and long latency. Radiosurgery carries the most promise for significant advances, however the process by which radiosurgery achieves obliteration is incompletely understood. Inflammation and thrombosis are likely to be important in the radiation response and may be amenable to pharmacological manipulation to improve radiosurgical efficacy. Materials and methods Immunohistochemistry and electron microscopy were used to study normal cerebral vessels, cavernous malformations and AVMs, some of which had previously been irradiated. An attempt was made to culture AVM endothelial cells to study the immediate response of AVM endothelium to radiosurgery. The effects of radiosurgery in a rat model of AVM were studied using immunohistochemistry and the results used to determine the choice of a pharmacological strategy to enhance the thrombotic effects of radiosurgery. Results Vascular malformations have a different endothelial inflammatory phenotype than normal cerebral vessels. Radiosurgery may cause long term changes in inflammatory molecule expression and leads to endothelial loss with exposure of pro-thrombotic molecules. Ultrastructural effects of irradiation include widespread cell loss, smooth muscle cell (SMC) proliferation and thrombosis. Endothelial culture from AVMs proved difficult due to SMC predominance in initial cultures. Radiosurgery upregulated several endothelial inflammatory molecules in the animal model and may induce pro-thrombotic cell membrane alterations. The administration of lipopolysaccharide and soluble tissue factor to rats following radiosurgery led to selective thrombosis of irradiated vessels. Conclusions Inflammation and thrombosis are important in the radiosurgical response of AVMs. Lumen obliteration appears to be mediated by proliferation of cells within the vessel wall and thrombosis. Upregulation of inflammatory molecules and perhaps disruption of the normal phospholipid asymmetry of the endothelial and SMC membranes are some of the earliest responses to radiosurgery. The alterations induced by radiation may be harnessed to selectively initiate thrombus formation. Stimulation of thrombosis may improve the efficacy of radiosurgery, increasing treatable lesion size and reducing latency.

<p>Amniocentesis (AC) and chorionic villus sampling (CVS) are the principal methods for fetal karyotyping. The aim of this thesis was to evaluate psychological reactions and risks associated with the procedures.</p><p>A semi-randomised study was made on 321 women, where AC (147) and CVS (174) at 10-13 weeks’ gestation were done trans-abdominally. Spontaneous fetal loss occurred in 6.8% and 1.7% of the women in the AC and CVS groups, respectively. Repeat testing was required more often in the AC (19.0%) than in the CVS (5.2%) group.</p><p>A subgroup of 94 women answered a questionnaire prior to the procedure. Anxiety was stated as reason for invasive testing in 38% of the women. Mean scores according to the Hospital Anxiety and Depression Scale for anxiety and depression were low. Likewise, mean scores for the Impact of Event Scale, evaluating the psychological distress evoked by the procedure, were low. Yet, a number of women had higher scores, indicating a risk of clinical anxiety and depression or psychological distress. The women worried most about miscarriage, fetal injury by the procedure and waiting for the result.</p><p>Fetal, infant and maternal outcomes were evaluated in a cohort of 71 586 women aged 35 to 49 years old, with single births in Sweden during 1991 to 1996. Altogether, 21 748 were exposed to AC and 1984 to CVS. Women exposed to AC and CVS were compared with non-exposed. Outcomes were extracted from the Swedish Medical Birth Register, the Swedish Hospital Discharge Register, and the Swedish Malformation Register. An increased risk of musculo-skeletal deformities, such as club foot (OR=1.45) and hip dislocation (OR=1.22), and respiratory disturbances such as neonatal pneumonia (OR=1.29), was found for infants born in the AC group. Risk increased with earlier gestation at the procedure. Fewer women in the AC group had a normal delivery and more had a Caesarean section. Complications related to the amniotic cavity and membranes (OR=1.15), hypotonic uterine dysfunction (OR=1.12) and instrumental vaginal deliveries (OR=1.11) were more common in the AC group. No significant differences were found for the CVS group.</p><p>CVS is the method of choice for prenatal karyotyping in the first trimester. AC should not be performed before 15 weeks’ gestation. Further research to develop methods to better identify women at increased risk of chromosomal abnormal pregnancies and to develop non-invasive tests for prenatal diagnosis is needed. Thereby, the number of women exposed to invasive procedures and the adverse effects caused by these procedures can be minimised.</p>

Amniocentesis (AC) and chorionic villus sampling (CVS) are the principal methods for fetal karyotyping. The aim of this thesis was to evaluate psychological reactions and risks associated with the procedures. A semi-randomised study was made on 321 women, where AC (147) and CVS (174) at 10-13 weeks’ gestation were done trans-abdominally. Spontaneous fetal loss occurred in 6.8% and 1.7% of the women in the AC and CVS groups, respectively. Repeat testing was required more often in the AC (19.0%) than in the CVS (5.2%) group. A subgroup of 94 women answered a questionnaire prior to the procedure. Anxiety was stated as reason for invasive testing in 38% of the women. Mean scores according to the Hospital Anxiety and Depression Scale for anxiety and depression were low. Likewise, mean scores for the Impact of Event Scale, evaluating the psychological distress evoked by the procedure, were low. Yet, a number of women had higher scores, indicating a risk of clinical anxiety and depression or psychological distress. The women worried most about miscarriage, fetal injury by the procedure and waiting for the result. Fetal, infant and maternal outcomes were evaluated in a cohort of 71 586 women aged 35 to 49 years old, with single births in Sweden during 1991 to 1996. Altogether, 21 748 were exposed to AC and 1984 to CVS. Women exposed to AC and CVS were compared with non-exposed. Outcomes were extracted from the Swedish Medical Birth Register, the Swedish Hospital Discharge Register, and the Swedish Malformation Register. An increased risk of musculo-skeletal deformities, such as club foot (OR=1.45) and hip dislocation (OR=1.22), and respiratory disturbances such as neonatal pneumonia (OR=1.29), was found for infants born in the AC group. Risk increased with earlier gestation at the procedure. Fewer women in the AC group had a normal delivery and more had a Caesarean section. Complications related to the amniotic cavity and membranes (OR=1.15), hypotonic uterine dysfunction (OR=1.12) and instrumental vaginal deliveries (OR=1.11) were more common in the AC group. No significant differences were found for the CVS group. CVS is the method of choice for prenatal karyotyping in the first trimester. AC should not be performed before 15 weeks’ gestation. Further research to develop methods to better identify women at increased risk of chromosomal abnormal pregnancies and to develop non-invasive tests for prenatal diagnosis is needed. Thereby, the number of women exposed to invasive procedures and the adverse effects caused by these procedures can be minimised.

Des mutations dans le gène doublecortine (DCX) sont responsables de lissencéphalie de type 1 ou d'hétérotopie laminaire sous-corticale. Les souris invalidées pour le gène Dcx sont épileptiques et présentent des anomalies hippocampiques, avec notamment la présence de deux couches de cellules pyramidales spécifiquement dans l'aire CA3 de cette structure. Cette hétérotopie hippocampique est associée à une hyperexcitabilité. Notre but est d'identifier les mécanismes moléculaires et cellulaires responsables de cette hyperexcitabilité chez les souris Dcx. Pendant ma thèse, j'ai pu isoler les neurones mal-positionnés de la région CA3 de l'hippocampe, afin de comparer leurs profils d'expression génique à ceux des neurones de la région CA3 des souris contrôles. Les résultats au stade P0 (jour de la naissance des souris), montrent que les profils d'expression génique de chacune des deux couches hétérotopiques présentes chez les souris Dcx, diffèrent entre eux ainsi qu'en comparaison avec les profils de la couche pyramidale des contrôles. Sur le plan fonctionnel, cette étude indique des perturbations au niveau des organelles intracellulaires, tels que les mitochondries et l'appareil de Golgi. En étudiant séparément les profils associés à chacune des deux couches des souris Dcx, nous avons mis en évidence des différences de degrés de maturité neuronale entre chacune des couches. L'utilisation de marqueurs moléculaires spécifiques aux couches en combinaison avec des expériences d'injections de bromo-désoxy-uridine (BrdU) une inversion des couches neuronales présentes chez les mutants. En complément des données d'expression génique, des analyses morphologiques et ultrastructurales indiquent que les cellules hétérotopiques, présentent des anomalies d'organelles intracellulaires, avec notamment des défauts de mitochondries et des modifications de l'appareil de Golgi. Qui plus est, nos données montrent une augmentation significative de la mort cellulaire dans les régions CA1 et CA3 de l'hippocampe. Aussi, nous avons également montré que les couches hétérotopiques étaient hétérogènes, présentant notamment des distributions anormales des précurseurs d'oligodendrocytes et des interneurones exprimant la somatostatine. Ces résultats ouvrent donc de nouvelles perspectives pour mieux comprendre la physiopathologie de ces maladies graves associées à des hétérotopies neuronales dans le cerveau, de l'épilepsie et des déficits cognitifs

CONTENT 1. INTRODUCTION 7 2. PATIENTS AND METHODS 8 2.1. Patients 8 2.2. Control Group 8 2.3. Study Methods 9 2.4. Treatment of Patients 9 2.5. Outcome State 10 2.6. Statistical Data Analysis 10 3. RESULTS 10 3.1. Clinical Manifestations of Cerebral Arteriovenous Malformations 10 3.2. Consciousness according to Glasgow Coma Scale 10 3.3. Distribution of Patients According to Spetzler-Martin Classification 11 3.4. Localization of Cerebral Arteriovenous Malformations 11 3.5. The Localization of Intracranial Haemorrhages after the Rupture of Cerebral Arteriovenous Malformations 11 3.6. Distribution of Patients with Intracerebral Haemorrhages after the Ruptures of Cerebral Arteriovenous Malformations and without Haemorrhages according to Spetzler-Martin classification 12 3.7. The Relationships between Haemorrhagic Manifestation and Size of Cerebral Arteriovenous Malformations 13 3.8. Transcranial Doppler Sonography Sensitivity and Specificity in Patients with Cerebral Arteriovenous Malformations 13 3.9. Cerebral Haemodynamics in Patients with Cerebral Arteriovenous Malformations and Healthy Controls 15 3.10. Cerebral Haemodynamics Changes in Patients with Cerebral Arteriovenous Malformations before and after the Surgery 16 3.11. Transcranial Doppler evaluation of Different Localizations Cerebral Arteriovenous Malformations 18 3.12. Cerebral Haemodynamics in Patients with Intracerebral Haematomas after Ruptures of Cerebral Arteriovenous Malformations 19 3.13. Cerebral... [to full text]

Pre-gestational diabetes increases the risk of congenital malformation in the offspring and both morbidity and mortality in the diabetic mother and her offspring. During pregnancy, high glucose levels act as a teratogen through several cellular and biochemical pathways and increased production of reactive oxygen species (ROS) has a central role in diabetic embryopathy. The aim of this work was to investigate the importance of genetic predisposition for congenital malformations and to study the genes involved in the teratogenic process of diabetic pregnancy. The crossbreeding of two rat strains, with both low and high incidence of diabetes-induced malformations, indicated that strain-specific maternal factors, such as disturbed serum levels of amino acids, triglycerides, and β-hydroxybutyrate, were associated with malformation. In addition, disturbed fetal expression of genes involved in ROS defense and development (Shh, Bmp4, Ret and Gdnf) in mandible and heart, and decreased activity of Gapdh and Aldose Reductase were associated with the teratogenic process, and the trans-generational heredity of the mother determined the type of malformations induced by maternal diabetes. In rat embryos, a diabetic environment in utero changed the expression of genes involved in ROS defense (Nrf2, Gpx1 and Cat), development of mandible and heart (Msx2, Shh, Bmp4, Ret and Gdnf), and neural tube closure and apoptosis (Pax3 and p53). The changes were divergent with tissue-specific alterations of gene expression in developing mandible, heart anlage, and whole embryo. Disruption of the Receptor for Advanced Glycation End products (RAGE) had a protective effect against diabetic embryopathy in mice, and the blockage of RAGE diminished ROS production in the offspring: this supported oxidative stress being a necessary etiological component in diabetic embryopathy. Maternal metabolic state and genetic susceptibility influence fetal outcome in experimental diabetic pregnancy. Disturbed protection against oxidative stress and tissue-specific derangements in the expression of developmental genes play pivotal roles in the teratogenic mechanism, and enhanced levels of Advanced Glycation End products (AGE) and RAGE-induced oxidative stress are involved in diabetic dysmorphogenesis.

OBJECTIVE: CLOVES syndrome (CLO: congenital lipomatous overgrowth, V: vascular anomalies E: epidermal nevi S: spinal anomalies) is a rare, non-heritable sporadic overgrowth disorder with serious morbidity. Previous anecdotal reports indicate that CLOVES patients are at risk for serious thromboembolic events in the perioperative period. The purpose of this study is to systematically determine the adverse events associated with anesthesia and diagnostic or interventional procedures for CLOVES patients, so appropriate assessment of risk can be performed and adequate precautions can be taken in the future to prevent complications. METHODS: We selected our study cohort by gathering patients in the Vascular Anomalies Center (VAC) database with the diagnosis of CLOVES syndrome. Our primary group of interest was patients that were anesthetized at Boston Children's Hospital (BCH) since 2005. All patients having the diagnosis of CLOVES were included. IRB approval was obtained prior to patient selection. Data was collected from BCH electronic medical records. Patient age, gender, ASA level, estimated amount of blood loss (EBL), surgery status, MRI status, complication(s), type of complication if any, and medical history was recorded in a Microsoft Excel document on a password-protected computer. Data analysis was carried out with no statistical analysis beyond simple incidence and prevalence of certain characteristics due to the extremely small patient population. RESULTS: We found that out of the 38 patients in our cohort, 15 (or 39%) suffered from complications during the perioperative period. A total of 23 (or 61%) did not have any complications. Results further showed that pulmonary emboli, respiratory issues, and hypo/hypertension were the most prevalent complications. In addition we found that there was no correlation between substantial EBL and complication occurrence in this cohort. CONCLUSION: In comparison to preliminary studies of Alomari, 2008 and Sapp et al., 2007, we report a lower occurrence of thromboembolic events in CLOVES patients. We hypothesize that this is because patients at BCH were treated aggressively with various prophylactic methods to help minimize the risk of such events. We recommend that early prophylactic anticoagulation methods are applied to future patients. Additionally, we recommend that CLOVES patients be followed by a hematologist and care team that are familiar with the condition throughout their stay at the hospital to reduce the risk of thromboembolic events.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / IntroduÃÃo. Dentre as malformaÃÃes, as fissuras labiopalatinas (FLPs) ocupam lugar de destaque, pois sÃo as deformidades craniofaciais de maior prevalÃncia. Classificam-se em: prÃ-forame, transforame, pÃs-forame e as submucosas, podendo diversos fatores estar associados à sua etiologia, tais como uso de drogas, carÃncia de Ãcido fÃlico, sÃfilis, toxoplasmose, radiaÃÃes ionizantes, tabagismo, alcoolismo no inÃcio da gestaÃÃo e os fatores genÃtico-hereditÃrios - os mais importantes. Outra teoria muito aceita à a multifatorial, que envolve a interaÃÃo de fatores genÃticos, ambientais e hereditÃrios. O objetivo do estudo foi determinar as caracterÃsticas epidemiolÃgicas de crianÃas portadoras de FLPs atendidas no Hospital Infantil Albert Sabin, Fortaleza-Ce. MÃtodos. Estudo descritivo de 390 portadores de FLPs atendidos no perÃodo de junho de 2008 a maio de 2009, com crianÃas menores de 12 anos de idade, no ambulatÃrio do NÃcleo de Atendimento Integrado ao Fissurado do Hospital Infantil Albert Sabin, principal hospital de referÃncia do Estado, procedentes de todo o CearÃ. Resultados. Observou-se que 51,3% dos pacientes com FLPs eram do sexo masculino e 48,2% do feminino, dos quais 37,4% foram provenientes da Capital, 62,6% do resto do Estado e 3,1% de outros UFs. O tipo mais prevalente foi a transforame, com 56,3% dos casos, seguida das pÃs-forame, com 21,6%, as prÃ-forame, com 20,3% e as submucosas com 1,8%. As lesÃes predominaram do lado esquerdo, com 43,2%, seguidas pelas bilaterais, com 32,5%. Verificou-se que 72,0% dos pacientes tiveram acesso à realizaÃÃo da queiloplastia. A palatoplastia foi efetuada em 47,2% das crianÃas, sendo que na faixa etÃria prÃ-escolar em somente 20% dos casos. Outros tipos de correÃÃes cirÃrgicas foram realizadas em somente 17,9% dos pesquisados. Outros 35,0% tiveram acesso ao tratamento fonoaudiolÃgico e 15,5% ao ortodÃntico. Encontrou-se ainda um percentual de 11,4% que apresentava algum outro tipo de malformaÃÃo congÃnita e outros 47,3% possuÃam um caso familial de fissura. ConclusÃes. A reduzida proporÃÃo de portadores de FLP com acesso aos tratamentos clÃnico-cirÃrgicos indica a existÃncia de uma carÃncia importante de centros e equipes multiprofissionais especializadas na reabilitaÃÃo destes pacientes. Mesmo com as dificuldades de deslocamento, 60% dos pacientes da pesquisa eram procedentes de municÃpios cearenses, o que sugere uma grande carÃncia deste tipo de atenÃÃo fora da Capital do Estado.

O objetivo deste trabalho foi investigar a ocorrência de mutações na sequência de nucleotídeos do gene AMELX, candidato a defeitos na formação do esmalte dentário, em indivíduos com e sem fissura labiopalatina. Para análise do gene proposto, foi coletado saliva de 165 indivíduos, que foram divididos em 4 grupos: Grupo 1 - composto por 46 indivíduos com fissura labiopalatina e malformação dentária; Grupo 2 - composto por 34 indivíduos com fissura labiopalatina e sem malformação dentária; Grupo 3 - composto por 34 indivíduos sem fissura labiopalatina e com malformação dentária e Grupo 4 - composto por 51 indivíduos sem fissura labiopalatina e malformação dentária. Foi realizada a extração do DNA genômico das amostras de saliva, seguido da PCR e sequenciamento direto. Cada mutação identificada no sequenciamento foi confirmada repetindo-se a reação de sequenciamento da fita antisenso. Após a coleta dos dados no Software SeqScape® 2.6, estes foram devidamente analisados por meio de gráficos e tabelas. Das amostras submetidas ao sequenciamento genético, obteve-se um aproveitamento de 95%, 90%, 89%, 88%, 94% e 100% destas amostras dos éxons 2, 3, 4, 5, 6 e 7, respectivamente. Dos 990 fragmentos sequenciados (seis éxons em 165 amostras de saliva), 918 fragmentos (93%) foram analisados. Detectou-se alteração na sequência de bases em 37 destes fragmentos (4%), sendo 14 no Grupo 1 (1,5%), 12 no Grupo 2 (1,3%), quatro no Grupo 3 (0,4%) e sete no Grupo 4 (0,7%), dos tipos missense e silenciosa, distribuídas nos éxons 2, 6 e 7 do gene AMELX, em oito distintos locais no cromossomo X. De acordo com os resultados obtidos do sequenciamento direto do gene AMELX, foi possível concluir que foram encontradas mutações na sequência de nucleotídeos do gene AMELX, em indivíduos com e sem fissura labiopalatina e malformação dentária. Observou-se ainda que a mutação localizada na posição 75 do éxon 6 esteve presente em todos os grupos estudados, sugerindo que, apesar de ser uma mutação silenciosa, pode ser um polimorfismo novo, a ser catalogado, pois foi detectado em 26 indivíduos, do total de 165, representando 16%. Entretanto, este estudo não pode afirmar que estas mutações alteraram diretamente o fenótipo dos pacientes dos grupos estudados. / The aim of this study was to investigate the occurrence of mutations in the AMELX candidate gene involved in enamel formation, in patients with and without cleft lip and palate and dental malformation. For gene analysis proposed was collected saliva from 165 patients who were divided in 4 groups: Group 1 - 46 individuals with cleft lip and palate and dental malformation, Group 2 - 34 individuals with cleft lip and palate without dental malformations; Group 3 - 34 individuals without cleft lip and palate with dental malformations and Group 4 - 51 individuals without cleft lip and palate and dental malformation. Next, genomic DNA was extracted from this saliva, followed by PCR and direct DNA sequencing. All samples with mutations were sequenced twice; once using the forward primer and a second time using the reverse primer. After data analysis with Software SeqScape® 2.6, the data were collated. Of the 165 samples, 95%, 90%, 89%, 88%, 94% and 100% of the samples were successfully sequenced from exons 2, 3, 4, 5, 6 and 7 respectively. Overall, of the 990 total sequenced exons (six exons in 165 samples of saliva), 918 exons (93%) were able to be completely sequenced and analyzed. Mutations were detected in 37 of the fragments (4%), more specifically, 14 in Group 1 (1.5%), 12 in Group 2 (1.3%), four in Group 3 (0.4%) and seven in Group 4 (0.7%), which included only missense and silent mutations, distributed throughout exons 2, 6 and 7 in the AMELX gene in eight different locations on chromosome X. According to the results obtained from direct sequencing of protein-coding exons of the AMELX gene, mutations were found in the nucleotide sequence of the AMELX gene in individuals with and without cleft lip and palate and dental malformation. It was also observed that the mutation in position 75 of exon 6 was present in all groups, suggesting that, though a silent mutation, may be a new polymorphism to be cataloged: it was found in 26 patients, the total of 165, representing 16%. However, this study cannot confirm that these mutations directly altered the phenotypes of the patients in the groups tested.