Longitudinal Natural History of Pediatric Subjects Affected with Mucopolysaccharidosis IIIB.

OBJECTIVE: To characterize the longitudinal natural history of disease progression in pediatric subjects affected with mucopolysaccharidosis (MPS) IIIB. STUDY DESIGN: Sixty-five children with a confirmed diagnosis of MPS IIIB were enrolled into 1 of 2 natural history studies and followed for up to 4 years. Cognitive and adaptive behavior functions were analyzed in all subjects, and volumetric magnetic resonance imaging analysis of liver, spleen, and brain, as well as levels of heparan sulfate (HS) and heparan sulfate nonreducing ends (HS-NRE), were measured in a subset of subjects. RESULTS: The majority of subjects with MPS IIIB achieved an apex on both cognition and adaptive behavior age equivalent scales between age 3 and 6 years. Development quotients for both cognition and adaptive behavior follow a linear trajectory by which subjects reach a nadir with a score <25 for an age equivalent of 24 months by age 8 years on average and by 13.5 years at the latest. All tested subjects (n = 22) had HS and HS-NRE levels above the normal range in cerebrospinal fluid and plasma, along with signs of hepatomegaly. Subjects lost an average of 26 mL of brain volume (-2.7%) over 48 weeks, owing entirely to a loss of cortical gray matter (32 mL; -6.5%). CONCLUSIONS: MPS IIIB exists along a continuum based on cognitive decline and cortical gray matter atrophy. Although a few individuals with MPS IIIB have an attenuated phenotype, the majority follow predicted trajectories for both cognition and adaptive behavior. TRIAL REGISTRATION: ClinicalTrials.gov identifiers NCT02493998, NCT03227042, and NCT02754076.

Audiologic evaluations of children with mucopolysaccharidosis / Avaliação audiológica em crianças com mucopolissacaridose

ABSTRACT INTRODUCTION: Mucopolysaccharidosis is a hereditary lysosomal storage disease, which develops due to a deficiency in the enzymes that play a role in the metabolism of glycosaminoglycans (GAG). The incidence of mucopolysaccharidosis is 1/25,000, with autosomal recessive inheritance (except for MPS II). Mucopolysaccharidosis occurs in seven different types, each with a different congenital deficiency of lysosomal enzymes. In mucopolysaccharidosis patients, even though progression of clinical findings is not prominent, the disease advances and causes death at early ages. Facial dysmorphism, growth retardation, mental retardation, and skeletal or joint dysplasia are the most frequently found symptoms in these patients. OBJECTIVE: The purpose of our study is to present the types of hearing loss types and tympanometric findings of patients with mucopolysaccharidosis referred to our clinic with suspicion of hearing loss. METHODS: After otorhinolaryngological examination, 9 patients with different types of mucopolysaccharidosis, underwent to immittance and audiometric evaluations, performed according to their physical and mental abilities, and ages, in order to determine their hearing thresholds. RESULTS: The audiometric findings of the 9 patients followed with mucopolysaccharidosis were reported separately for each case. CONCLUSION: Based on the high frequency of hearing loss in mucopolysaccharidosis patients, early and detailed audiological evaluations are highly desirable. Therefore, regular and systematic multidisciplinary evaluations are very important.

Resumo Introdução: Mucopolissacaridose (MPS) é uma doença hereditária de depósito lisossômico, decorrente da deficiência das enzimas que influenciam o metabolismo dos glicosaminoglicanos (GAGs). A incidência de MPS é de 1/25.000 habitantes, resultante de herança autossômica recessiva (exceto no caso de MPS II). MPS se apresenta na forma de sete tipos diferentes e, em cada tipo, ocorre uma deficiência congênita distinta de enzimas lisossômicas. Embora em pacientes com MPS os achados clínicos não sejam geralmente observados, a doença progride em seu curso natural e costuma levar a óbito pacientes muito jovens. Dismorfismo facial, retardo de crescimento, retardo mental e displasia esquelética ou articular são os sinais e sintomas mais frequentemente observados nesses pacientes. Objetivo: A finalidade do presente estudo foi apresentar os tipos de perda auditiva e os achados timpanométricos de pacientes com MPS encaminhados para nossa clínica com suspeita de perda auditiva. Método: Em seguida ao exame otorrinolaringológico, nove pacientes com diferentes tipos de MPS, foram submetidos a avaliações imitanciométricas e testes audiométricos de acordo com sua faixa etária eficiência física e mental, no intuito de identificar seus limiares auditivos. Resultados: Os achados audiométricos dos nove pacientes acompanhados por MPS foram descritos separadamente para cada caso. Conclusão: Baseado na alta frequência de perda auditiva em pacientes com MPS, avaliação audiológica precoce e detalhada é altamente desejável. Para tanto, é importante que sejam realizados avaliações multidisciplinares periódicas e sistemáticas.

Audiologic evaluations of children with mucopolysaccharidosis.

INTRODUCTION: Mucopolysaccharidosis is a hereditary lysosomal storage disease, which develops due to a deficiency in the enzymes that play a role in the metabolism of glycosaminoglycans (GAG). The incidence of mucopolysaccharidosis is 1/25,000, with autosomal recessive inheritance (except for MPS II). Mucopolysaccharidosis occurs in seven different types, each with a different congenital deficiency of lysosomal enzymes. In mucopolysaccharidosis patients, even though progression of clinical findings is not prominent, the disease advances and causes death at early ages. Facial dysmorphism, growth retardation, mental retardation, and skeletal or joint dysplasia are the most frequently found symptoms in these patients. OBJECTIVE: The purpose of our study is to present the types of hearing loss types and tympanometric findings of patients with mucopolysaccharidosis referred to our clinic with suspicion of hearing loss. METHODS: After otorhinolaryngological examination, 9 patients with different types of mucopolysaccharidosis, underwent to immittance and audiometric evaluations, performed according to their physical and mental abilities, and ages, in order to determine their hearing thresholds. RESULTS: The audiometric findings of the 9 patients followed with mucopolysaccharidosis were reported separately for each case. CONCLUSION: Based on the high frequency of hearing loss in mucopolysaccharidosis patients, early and detailed audiological evaluations are highly desirable. Therefore, regular and systematic multidisciplinary evaluations are very important.