GNPTAB missense mutations cause loss of GlcNAc-1-phosphotransferase activity in mucolipidosis type II through distinct mechanisms.

Mucolipidoses (ML) II and III alpha/beta are lysosomal storage diseases caused by pathogenic mutations in GNPTAB encoding the α/ß-subunit precursor of GlcNAc-1-phosphotransferase. To determine genotype-phenotype correlation and functional analysis of mutant GlcNAc-1-phosphotransferase, 13 Brazilian patients clinically and biochemical diagnosed for MLII or III alpha/beta were studied. By sequencing of genomic GNPTAB of the MLII and MLIII alpha/beta patients we identified six novel mutations: p.D76G, p.S385L, p.Q278Kfs*3, p.H588Qfs*27, p.N642Lfs*10 and p.Y1111*. Expression analysis by western blotting and immunofluorescence microscopy revealed that the mutant α/ß-subunit precursor p.D76G is retained in the endoplasmic reticulum whereas the mutant p.S385L is correctly transported to the cis-Golgi apparatus and proteolytically processed. Both mutations lead to complete loss of GlcNAc-1-phosphotransferase activity, consistent with the severe clinical MLII phenotype of the patients. Our study expands the genotypic spectrum of MLII and provides novel insights into structural requirements to ensure GlcNAc-1-phosphotransferase activity.

Extension of the molecular analysis to the promoter region of the iduronate 2-sulfatase gene reveals genomic alterations in mucopolysaccharidosis type II patients with normal coding sequence.

Hunter disease or mucopolysaccharidosis type II (MPS II) is an X-linked recessive lysosomal disorder caused by the deficit of the enzyme iduronate-2-sulfatase (IDS), involved in the catabolism of the glycosaminoglycans heparan and dermatan sulfate. Our aim was to search for molecular defects in the promoter region of the IDS gene in patients with previous biochemical diagnosis of MPS II and after we sequenced the whole IDS coding region and the exon/intron boundaries without detecting any pathogenic mutations. Screening of the promoter region of four patients detected in two of them a 178 bp deletion and in the other two a single nucleotide substitution 818 bp upstream of the coding region. The latter had never been described before in MPS II patients and it turned out to be a polymorphism. Our experience suggests that MPS II patients with no mutations detected in the IDS coding region should be screened in the promoter region of the gene. Findings will hopefully help to clarify the relationship between genotype and phenotype and will be useful for the correct molecular diagnosis of Hunter patients and the identification of female carriers, the latter particularly important for genetic counseling.

Síndrome de Lujan-Fryns: recorrência familiar na mesma geração / Lujan-Fryns syndrome: familial recurrence in the same generation

Objetivos: relatar casos da Síndrome de Lujan-Fryns em dois irmãos.Descrição dos casos: Paciente 1 ? sexo masculino, 18 anos, apresentando alta estatura, hiperextensibilidade articular, região frontal proeminente, face longa e estreita, hipoplasia do maxilar, mandíbula pequena, nariz largo com ponte nasal alta e estreita, filtro curto e profundo, lábio superior fino e palato arqueado, voz hipernasal e hipotonia generalizada. Instabilidade emocional, distúrbio de aprendizagem, timidez e fobia social. Prolapso de válvula mitral com refluxo discreto e ectasia da raiz da aorta Miopia, sem retinopatia. Resultados normais para cariótipo em sangue periférico com banda G, análise molecular para X frágil e investigação para homocistinúria. Paciente 2 ? sexo feminino,22 anos, apresenta quadro clínico semelhante ao paciente 1 (seu irmão), porém de intensidade mais leve. Exames complementares sem alterações significativas.Conclusões: os pacientes apresentam aspecto marfanóide e retardo mental compatível com herança ligada ao X. Apesar de ainda não ter sido realizada a pesquisa da mutação no gene MED 12, o diagnóstico clínico de Síndrome de Lujan-Fryns está respaldado pela literatura. Não existe tratamento específico e os pacientes requerem educação especial e acompanhamento psicológico.

Aims: To report cases of Lujan-Fryns syndrome in two siblings.Description of cases: Patient 1 ? male, 16 years, presented high stature, hiperextensibility of joints, prominent forehead, long face and narrow, maxillary hypoplasia, small jaw, large nose with high and narrow nasal bridge and short and deep filter, thin upper lip and arched palate, hypernasal voice and generalized hypotonia. Lability, learning disabilities, timidity and social phobia. Mitral valve prolapse with slight reflux and dilatation of the aortic root. Myopia without retinopathy. Karyotype in peripheral blood with G-band, molecular analysis for fragile X and biochemical investigation for homocystinuria had normal results. Patient 2 ? female, 19 years, presented clinical symptoms similar to the patient 1 (her brother), although milder. Complementary tests showed no significant changes.Conclusions: These patients present marfanoid aspect and mental retardation consistent with X-linked inheritance. Although no research has been carried out on mutation in the gene MED 12, the clinical diagnosis of Lujan-Fryns syndrome is supported by the literature. There is no specific treatment, and the patients require special education and psychological counseling.

[Enzyme replacement therapy for mucopolysaccharidoses I, II and VI: recommendations from a group of Brazilian F experts]. / Terapia de reposição enzimática para as mucopolissacaridoses I, II e VI: recomendações de um grupo de especialistas brasileiros.

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by deficiency of specific lysosomal enzymes that affect catabolism of glycosaminoglycans (GAG). Accumulation of GAG in various organs and tissues in MPS patients results in a series of signs and symptoms, producing a multisystemic condition affecting bones and joints, the respiratory and cardiovascular systems and many other organs and tissues, including in some cases, cognitive performance. So far, eleven enzyme defects that cause seven different types of MPS have been identified. Before introduction of therapies to restore deficient enzyme activity, treatment of MPS focused primarily on prevention and care of complications, still a very important aspect in the management of these patients. In the 80's treatment of MPS with bone marrow transplantation/hematopoietic stem cells transplantation (BMT/HSCT) was proposed and in the 90's, enzyme replacement therapy (ERT),began to be developed and was approved for clinical use in MPS I, II and VI in the first decade of the 21st century. The authors of this paper are convinced that a better future for patients affected by mucopolysaccharidoses depends upon identifying, understanding and appropriately managing the multisystemic manifestations of these diseases. This includes the provision of support measures (which should be part of regular multidisciplinary care of these patients) and of specific therapies. Although inhibition of synthesis of GAG and the recovery of enzyme activity with small molecules also may play a role in the management of MPS, the breakthrough is the currently available intravenous ERT. ERT radically changed the setting for treatment of mucopolysaccharidosis I, II and VI in the last decade., Benefits can even be extended soon to MPS IV A (ERT for this condition is already in clinical development), with prediction for treatment of MPS III A and the cognitive deficit in MPS II by administration of the enzyme directly into the central nervous system (CNS). A large number of Brazilian services, from all regions of the country, already have experience with ERT for MPS I, II and VI. This experience was gained not only by treating patients but also with the participation of some groups in clinical trials involving ERT for these conditions. Summing up the three types of MPS, more than 250 patients have already been treated with ERT in Brazil. The experience of professionals coupled to the data available in international literature, allowed us to elaborate this document, produced with the goal of bringing together and harmonize the information available for the treatment of these severe and progressive diseases, which, fortunately, are now treatable, a situation which bring new perspectives for Brazilian patients, affected by these conditions.

Mucopolysaccharidosis I, II, and VI: Brief review and guidelines for treatment.

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions.

Mucopolysaccharidosis I, II, and VI: brief review and guidelines for treatment

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by the deficiency of one of the lysosomal enzymes involved in the glycosaminoglycan (GAG) breakdown pathway. This metabolic block leads to the accumulation of GAG in various organs and tissues of the affected patients, resulting in a multisystemic clinical picture, sometimes including cognitive impairment. Until the beginning of the XXI century, treatment was mainly supportive. Bone marrow transplantation improved the natural course of the disease in some types of MPS, but the morbidity and mortality restricted its use to selected cases. The identification of the genes involved, the new molecular biology tools and the availability of animal models made it possible to develop specific enzyme replacement therapies (ERT) for these diseases. At present, a great number of Brazilian medical centers from all regions of the country have experience with ERT for MPS I, II, and VI, acquired not only through patient treatment but also in clinical trials. Taking the three types of MPS together, over 200 patients have been treated with ERT in our country. This document summarizes the experience of the professionals involved, along with the data available in the international literature, bringing together and harmonizing the information available on the management of these severe and progressive diseases, thus disclosing new prospects for Brazilian patients affected by these conditions.

Terapia de reposição enzimática para as mucopolissacaridoses I, II e VI: recomendações de um grupo de especialistas brasileiros / Enzyme replacement therapy for mucopolysaccharidoses I, II and VI: recommendations from a group of Brazilian F experts

As mucopolissacaridoses (MPS) são doenças genéticas raras causadas pela deficiência de enzimas lisossômicas específicas que afetam o catabolismo de glicosaminoglicanos (GAG). O acúmulo de GAG em vários órgãos e tecidos nos pacientes afetados pelas MPS resulta em uma série de sinais e sintomas, integrantes de um quadro clínico multissistêmico que compromete ossos e articulações, vias respiratórias, sistema cardiovascular e muitos outros órgãos e tecidos, incluindo, em alguns casos, as funções cognitivas. Já foram identificados 11 defeitos enzimáticos que causam sete tipos diferentes de MPS. Antes do advento de terapias dirigidas para a restauração da atividade da enzima deficiente, o tratamento das MPS tinha como principal foco a prevenção e o cuidado das complicações, aspecto ainda bastante importante no manejo desses pacientes. Na década de 80 foi proposto o tratamento das MPS com transplante de medula óssea/transplante de células tronco hematopoiéticas (TMO/TCTH) e na década de 90 começou o desenvolvimento da Terapia de Reposição Enzimática (TRE), que se tornou uma realidade aprovada para uso clínico nas MPS I, II e VI na primeira década do século 21. Os autores deste trabalho têm a convicção de que um melhor futuro para os pacientes afetados pelas MPS depende da identificação, compreensão e manejo adequado das manifestações multissistêmicas dessas doenças, incluindo medidas de suporte (que devem fazer parte da assistência multidisciplinar regular destes pacientes) e terapias específicas...

Mucopolysaccharidoses (MPS) are rare genetic diseases caused by deficiency of specific lysosomal enzymes that affect catabolism of glycosaminoglycans (GAG). Accumulation of GAG in various organs and tissues in MPS patients results in a series of signs and symptoms, producing a multisystemic condition affecting bones and joints, the respiratory and cardiovascular systems and many other organs and tissues, including in some cases, cognitive performance. So far, eleven enzyme defects that cause seven different types of MPS have been identified. Before introduction of therapies to restore deficient enzyme activity, treatment of MPS focused primnarily on prevention and care of complications, still a very important aspect in the management of these patients. In the 80's treatment of MPS with bone marrow transplantation/hematopoietic stem cells transplantation (BMT/HSCT) was proposed and in the 90's, enzyme replacement therapy (ERT),began to be developed and was approved for clinical use in MPS I, II and VI in the first decade of the 21st century. The authors of this paper are convinced that a better future for patients affected by mucopolysaccharidoses depends upon identifying, understanding and appropriately managing the multisystemic manifestations of these diseases. This includes the provision of support measures (which should be part of regular multidisciplinary care of these patients) and of specific therapies...

Síndrome Alcoólica Fetal ? recorrência em duas gerações de uma família / Fetal Alcohol Syndrome ? recurrence in two generations of a family

Objetivos: descrever um caso de recorrência da Síndrome Alcoólica Fetal em duas gerações de uma família brasileira. Descrição do caso: uma paciente de 24 anos, filha de mãe alcoólatra, foi adotada ainda no período neonatal e teve diagnóstico confirmado de Síndrome Alcoólica Fetal. A paciente começou a consumir bebidas alcoólicas durante a adolescência, mantendo o etilismo durante a primeira e segunda gestação, com ambos os conceptos apresentando Síndrome Alcoólica Fetal ao nascimento. Na terceira gestação, não houve ingestão de bebidas alcoólicas, nascendo uma menina não acometida pela síndrome. Todos os indivíduos acometidos preenchem os critérios diagnósticos: exposição pré-natal ao álcool, dismorfismo crânio-facial, deficiência de crescimento (baixa estatura) e acometimento do sistema nervoso central.Conclusões: apesar da recorrência de Síndrome Alcoólica Fetal ser relativamente frequente entre irmãos e estar bem documentada na literatura, a recorrência familial em indivíduos de duas gerações (como mãe-filhos) é rara. Sendo uma síndrome evitável, há necessidade de intervenção multiprofissional e interdisciplinar na prevenção da mesma, atuando não apenas nos grupos de risco, como mulheres alcoólatras, mas também em mulheres jovens, etilistas sociais e com vida sexual ativa, conscientizando-as sobre os possíveis efeitos da exposição ao álcool na gestação.

Aims: To report a case of recurrence of fetal alcohol syndrome in two generations of a brazilian family. Case description: A 24-year old female, daughter of an alcohol addicted woman, was adopted during neonatal period, and had fetal alcohol syndrome diagnosis confirmed. She started alcohol consumption during her adolescence and had alcohol exposure during her first and second pregnancies, with both newborns showing signs of fetal alcohol syndrome at birth. In her third pregnancy, there was no alcohol exposure and she gave birth to a non-affected daughter. All affected patients fulfill the diagnosis criteria: alcohol pre-natal exposure, cranio-facial dysmorphism, growth retardation (short stature) and central nervous system involvement.Conclusions: Although the recurrence in fetal alcohol syndrome is quite common among siblings and has been well documented in literature, the recurrence in relatives from different generations, such as mother-child occurrence, is rare. Given that this is a preventable syndrome, it is important to implement an interdisciplinary approach, not only for groups with risk factors, but educating women in general about the deleterious effects of alcohol ingestion during pregnancy.