Clinicogenetic lessons from 370 patients with autosomal recessive limb-girdle muscular dystrophy.

Limb-girdle muscular dystrophies (LGMD) are a group of genetically heterogeneous disorders characterized by predominantly proximal muscle weakness. We aimed to characterize epidemiological, clinical and molecular data of patients with autosomal recessive LGMD2/LGMD-R in Brazil. A multicenter historical cohort study was performed at 13 centers, in which index cases and their affected relatives' data from consecutive families with genetic or pathological diagnosis of LGMD2/LGMD-R were reviewed from July 2017 to August 2018. Survival curves to major handicap for LGMD2A/LGMD-R1-calpain3-related, LGMD2B/LGMD-R2-dysferlin-related and sarcoglycanopathies were built and progressions according to sex and genotype were estimated. In 370 patients (305 families) with LGMD2/LGMD-R, most frequent subtypes were LGMD2A/LGMD-R1-calpain3-related and LGMD2B/LGMD-R2-dysferlin-related, each representing around 30% of families. Sarcoglycanopathies were the most frequent childhood-onset subtype, representing 21% of families. Five percent of families had LGMD2G/LGMD-R7-telethonin-related, an ultra-rare subtype worldwide. Females with LGMD2B/LGMD-R2-dysferlin-related had less severe progression to handicap than males and LGMD2A/LGMD-R1-calpain3-related patients with truncating variants had earlier disease onset and more severe progression to handicap than patients without truncating variants. We have provided paramount epidemiological data of LGMD2/LGMD-R in Brazil that might help on differential diagnosis, better patient care and guiding future collaborative clinical trials and natural history studies in the field.

Guidelines for the diagnosis, treatment and clinical monitoring of patients with juvenile and adult Pompe disease / Diretriz para o diagnóstico, tratamento e acompanhamento clínico de pacientes com doença de Pompe juvenil e do adulto

ABSTRACT Pompe disease (PD) is a potentially lethal illness involving irreversible muscle damage resulting from glycogen storage in muscle fiber and activation of autophagic pathways. A promising therapeutic perspective for PD is enzyme replacement therapy (ERT) with the human recombinant enzyme acid alpha-glucosidase (Myozyme®). The need to organize a diagnostic flowchart, systematize clinical follow-up, and establish new therapeutic recommendations has become vital, as ERT ensures greater patient longevity. A task force of experienced clinicians outlined a protocol for diagnosis, monitoring, treatment, genetic counseling, and rehabilitation for PD patients. The study was conducted under the coordination of REBREPOM, the Brazilian Network for Studies of PD. The meeting of these experts took place in October 2013, at L’Hotel Port Bay in São Paulo, Brazil. In August 2014, the text was reassessed and updated. Given the rarity of PD and limited high-impact publications, experts submitted their views.

RESUMO A doença de Pompe (DP) é uma doença grave, potencialmente letal, devida ao depósito de glicogênio na fibra muscular e ativação de vias autofágicas. Tratamento promissor para a DP é a reposição enzimática com a enzima recombinante humana alfa-glicosidase ácida (rhAGA -Myozyme®). A necessidade de organizar uma propedêutica diagnóstica, sistematizar o seguimento clínico e sedimentar as novas recomendações terapêuticas tornaram-se vitais à medida que o tratamento permite uma maior longevidade aos pacientes. Uma força-tarefa de clínicos experientes no manejo da DP foi constituída para elaborar um protocolo para o diagnóstico, acompanhamento clínico, tratamento, aconselhamento genético, entre outras considerações voltadas ao paciente adulto. O estudo foi realizado sob a coordenação da Rede Brasileira de Estudos da Doença de Pompe (REBREPOM). Diante da raridade da DP e escassez de trabalhos de alto impacto de evidência científica, os especialistas emitiram suas opiniões.

Guidelines for the diagnosis, treatment and clinical monitoring of patients with juvenile and adult Pompe disease.

Pompe disease (PD) is a potentially lethal illness involving irreversible muscle damage resulting from glycogen storage in muscle fiber and activation of autophagic pathways. A promising therapeutic perspective for PD is enzyme replacement therapy (ERT) with the human recombinant enzyme acid alpha-glucosidase (Myozyme®). The need to organize a diagnostic flowchart, systematize clinical follow-up, and establish new therapeutic recommendations has become vital, as ERT ensures greater patient longevity. A task force of experienced clinicians outlined a protocol for diagnosis, monitoring, treatment, genetic counseling, and rehabilitation for PD patients. The study was conducted under the coordination of REBREPOM, the Brazilian Network for Studies of PD. The meeting of these experts took place in October 2013, at L'Hotel Port Bay in São Paulo, Brazil. In August 2014, the text was reassessed and updated. Given the rarity of PD and limited high-impact publications, experts submitted their views.

Pompe disease in a Brazilian series: clinical and molecular analyses with identification of nine new mutations.

Pompe disease (glycogen storage disease type II or acid maltase deficiency) is an inherited autosomal recessive deficiency of acid alpha-glucosidase (GAA), with predominant manifestations of skeletal muscle weakness. A broad range of studies have been published focusing on Pompe patients from different countries, but none from Brazil. We investigated 41 patients with either infantile-onset (21 cases) or late-onset (20 cases) disease by muscle pathology, enzyme activity and GAA gene mutation screening. Molecular analyses identified 71 mutant alleles from the probands, nine of which are novel (five missense mutations c.136T > G, c.650C > T, c.1456G > C, c.1834C > T, and c.1905C > A, a splice-site mutation c.1195-2A > G, two deletions c.18_25del and c.2185delC, and one nonsense mutation c.643G > T). Interestingly, the c.1905C > A variant was detected in four unrelated patients and may represent a common Brazilian Pompe mutation. The c.2560C > T severe mutation was frequent in our population suggesting a high prevalence in Brazil. Also, eight out of the 21 infantile-onset patients have two truncating mutations predicted to abrogate protein expression. Of the ten late-onset patients who do not carry the common late-onset intronic mutation c.-32-13T > G, five (from three separate families) carry the recently described intronic mutation, c.-32-3C > A, and one sibpair carries the novel missense mutation c.1781G > C in combination with known severe mutation c.1941C > G. The association of these variants (c.1781G > C and c.-32-3C > A) with late-onset disease suggests that they allow for some residual activity in these patients. Our findings help to characterize Pompe disease in Brazil and support the need for additional studies to define the wide clinical and pathological spectrum observed in this disease.

Miopatias distais: análise clínica, laboratorial, eletromiográfica, histológico-histoquímica de oito casos / Distal myopathies: clinical, laboratorial, electromyographic, histologic-histochemical analysis of 8 cases

As miopatias distais säo entidades raras e de dificil classificaçäo. Descrevemos oito casos de miopatias distais, cinco do sexo masculino e três do feminino, em que o início dos sintomas ocorreu aos 10 anos em cinco e aos 20 em três. O início dos síntomas se deu na musculatura distal dos membros inferiores e a seguir dos membros superiores, posteriormente afetando as porçöes proximais dos quatro membros. As enzimas séricas de origem muscular mostraram discreta elevaçäo em cinco casos, moderada em um e importante em dois. As eletromiografias sugeriram miopatia primária em quatro, desinervaçäo em dois e era de tipo neuromiopático em outro. As biópsias musculares revelaram sinais de envolvimento misto (miopatia e desinervaçäo) em dois casos, miopatia crônica ativa em cinco e miopatia crônica em um. Quatro casos apresentavam vacúolos com conteúdo positivo na fosfatase ácida, em dois do tipo marginado. Seis casos mostraram importante aumento focal da fosfatase ácida sugerindo patogenia com importante participaçäo lisosomal. Dois dos casos foram classificadoscomo miopatia distal autossômica recessiva variante de Welander; dois, como autossômica recessiva tipo Miyoshi; dois, como autossômica recessiva com vacúolos marginados (Myzuzawa e Nonaka); e dois, na classificaçäo de miscelânia