A novel spot mutation leading to sialidosis type 1-myoclonus syndrome and optical coherence tomography findings / Uma nova mutação pontual levando à sialidose tipo 1 - síndrome mioclônica e seus achados na tomografia de coerência óptica

ABSTRACT This report presents the optical coherence tomography findings and a new NEU1 mutation in bilateral macular cherry-red spot syndrome associated with sialidosis type 1. A 19-year-old patient with a macular cherry-red spot underwent metabolic and genetic analyses supported by spectral-domain optical coherence tomography. Fundus examination revealed bilateral macular cherry-red spot. Spectral-domain optical coherence tomography revealed increased hyperreflectivity in the retinal inner layers and the photoreceptor layer in the foveal region. The genetic analysis detected a new NEU1 mutation, which caused type I sialidosis. In cases with a macular cherry-red spot, sialidosis should be included in the differential diagnosis, and NEU1 mutation should be screened. Spectral-domain optical coherence tomography alone is not sufficient in the differential diagnosis because childhood metabolic diseases may exhibit similar signs.

RESUMO Neste artigo, objetivamos apresentar os achados da tomografia de coerência óptica em uma nova mutação detectada no gene NEU1 em um caso de síndrome macular vermelho-cereja bilateral associada à sialidose tipo 1. Um paciente de 19 anos com um achado de mancha macular vermelho-cereja foi submetido a análises metabólicas e genéticas, apoiadas por imagens de tomografia de coerência óptica de domínio espectral (SD-OCT). Ao exame de fundo de olho, foi observada uma mancha macular vermelho-cereja bilateral. Nas imagens de SD-OCT, observou-se hiper-refletividade nas camadas internas da retina e na camada fotorreceptora na região foveal. Foi realizada uma análise genética e uma nova mutação foi detectada no gene NEU1, resultando em sialidose tipo 1. Nos casos em que é detectada uma mancha vermelho-cereja na mácula, o diagnóstico diferencial de sialidose deve ser feito e mutações do gene NEU1 devem ser rastreadas. A SD-OCT por si só não é suficiente para o diagnóstico diferencial, porque achados de aparência semelhante podem se manifestar em casos de doenças metabólicas da infância.

A decade of molecular diagnosis of Mucolipidosis II and III in Brazil: a pooled analysis of 32 patients

Abstract GlcNAc-1-phosphotransferase is a hexameric complex formed by subunits α, β, and γ, where the first two are encoded by the GNPTAB gene and the third by the GNPTG gene. Pathogenic variants identified in the GNPTAB gene cause the diseases Mucolipidosis II and III alpha/beta, which are severe and characterized by an overflow of lysosomal hydrolases into the extracellular environment, and their absence in lysosomal compartments causes an accumulation of non-degraded macromolecules. Methodology: a retrospective study that included 32 unrelated Brazilian patients with a clinical and genetic diagnosis of Mucolipidosis II/III alpha/beta. The regional frequency of the altered alleles was determined. Results: The patients were from all regions of Brazil. The most prevalent variants were c.3503_3504del, associated with the severe form of the disease, and c.1208T>C, associated with the milder form. Variant c.3503_3504del is the most frequently found in the Midwest, Northeast, and Southeast regions of Brazil. In the South, 42.8% of the alleles present the c.1196C>T variant. Conclusions: From the perspective of all patients diagnosed with Mucolipidosis II/III in Brazil, it is possible to conclude that different regions present allelic frequencies of specific pathogenic variants, which can be explained by the occurrence of a founding effect or high inbreeding rates.

Diagnóstico clínico y genético mucolipidosis II - enfermedad células de inclusión / Diagnóstico clínico e genético da mucolipidose II - doença das células de inclusão / Clinical and genetic diagnosis of mucolipidosis II - inclusion cell disease

La Mucolipidosis tipo II es una enfermedad autosómica trastorno recesivo clínicamente caracterizado por la dismorfia facial y una hiperplasia gingival severa. Relato del caso: Se porta caso de paciente de 2 años de edad, con diagnóstico de enfermedad metabólica tipo mucolipidosis II. Al examen físico se encontraron facies tosca, marcada hiperplasia gingival sintomática generalizada en maxilar superior e inferior, encías sangrantes, cuello corto, con regular sostén cefálico, piel delgada, pectus excavatus, codos normales, manos con disminución en el agarre y piel gruesa con xerosis, dificultad para elevar los brazos por encima de la cabeza, retardo global en neurodesarrollo. Por lo cual se manejó el caso de manera multidisciplinaria, permitiendo que el paciente evolucione de manera positiva al tratamiento integral, con mejoramiento en la motricidad. Conclusiones: Los fenotipos clínicos superpuestos son un desafío de diagnóstico para el personal de la salud en Odontología, especialmente en casos de mucolipidosis (ML) y trastornos mucopolisacáridos (MPS), debido a la superposición de las características clínicas

A mucolipidose tipo II é um distúrbio autossômico recessivo caracterizado clinicamente por dismorfia facial e hiperplasia gengival grave. Relato de caso: É relatado o caso de uma paciente de 2 anos com diagnóstico de doença metabólica do tipo mucolipidose II. O exame físico revelou fácies grosseira, hiperplasia gengival sintomática generalizada acentuada na mandíbula superior e inferior, gengivas sangrantes, pescoço curto, com apoio de cabeça regular, pele fina, pectus excavatus, cotovelos normais, mãos com pega diminuída e pele grossa com xerose, dificuldade em levantar os braços acima da cabeça, atraso no desenvolvimento neurológico global. Portanto, o caso foi tratado de forma multidisciplinar, permitindo que o paciente evoluísse de forma positiva para um tratamento integral, com melhora nas habilidades motoras. Conclusões: A sobreposição de fenótipos clínicos é um desafio diagnóstico para o pessoal de saúde em Odontología, especialmente nos casos de mucolipidose (ML) e distúrbios dos mucopolissacarídeos (MPS), devido à sobreposição de características clínicas

Mucolipidosis type II is an autosomal recessive disorder clinically characterized by facial dysmorphia and severe gingival hyperplasia. Case report: The case of a 2-year-old patient with a diagnosis of metabolic disease type mucolipidosis II is reported. Physical examination revealed coarse facies, marked generalized symptomatic gingival hyperplasia in the upper and lower jaw, bleeding gums, short neck, with regular head support, thin skin, pectus excavatus, normal elbows, hands with decreased grip, and thick skin with xerosis, difficulty raising the arms above the head, global neurodevelopmental delay. Therefore, the case was handled in a multidisciplinary way, allowing the patient to evolve in a positive way to comprehensive treatment, with improvement in motor skills. Conclusions: Overlapping clinical phenotypes are a diagnostic challenge for health personnel in Dentistry, especially in cases of mucolipidosis (ML) and mucopolysaccharide disorders (MPS), due to the overlapping of clinical characteristics

Preliminary analysis of clinically relevant indicators in two patients with mucolipidosis type Ⅲ and their family members / 中国中西医结合急救杂志

Objective To observe the clinical characteristics of 2 patients with mucolipidosis type Ⅲ. Methods Two sibling patients (a sister and a brother) with mucolipidosis type Ⅲ symptoms and other family members were the research objects, and the changes of their features of hand bone imaging, blood indexes [blood glucose, cholesterol, triacylglycerol (TG), total protein (TP), albumin (Alb)] and body composition were analyzed. Results Except the 2 patients, the bone morphology, blood indexes and body compositions in other 7 family members were under normal conditions. The phalanx intervals of both hands in 2 patients with mucolipidosis type Ⅲwere widened significantly, among them the thumb manifestation was more obvious; the distal segments of phalanxes in both hands became pointed and curved presenting a "claw-like hand" deformity; the metacarpal and distal carpal metaphysis were obviously enlarged, and scaphoid, lunate, trianglar, orbicular, and trapezium and trapezoid bones were loosely arranged at the wrist; the distal ends of ulna and radius were markedly enlarged. Compared to healthy people, the triglyceride levels of serum in the 2 patients were obviously reduced (the percentage of reduction: 57.14% and 41.07% respectively); body mass indexes (BMI), total fat and visceral fat were significantly lowered (BMI reduction percentage:26.81% and 14.55%, total fat reduction percentage: 38.12% and 44.95%, visceral fat reduction percentage: 62.25% and 67.74%, respectively) in the two patients. Conclusion The purpose of studying the biochemistry indexes, imaging characteristics and body compositions is to more deeply understand the clinical symptoms and signs of the 2 sibling patients with mucolipidosis type Ⅲ in a family to provide a theoretical reference.

Aortic Valve Replacement for Two Siblings with Mucolipidosis Type III / 日本心臓血管外科学会雑誌

Mucolipidosis is an autosomal recessive lysosomal storage disorder that demonstrates a clinical resemblance to mucopolysaccharidosis. Accumulation of glycoproteins throughout the body causes dysfunction of several organs, in particular, valvular heart diseases are an important cause of mortality, however, there is no consensus guideline regarding the indications and optimal timing of the surgical repair because of the unclear and short natural history. Here we present 12- and 15-year-old siblings diagnosed with mucolipidosis who underwent aortic valve replacement. The senior sibling received redo-aortic valve replacement for prosthetic valve dysfunction 11 years after the initial surgery. A few surgical valve replacements in patients with mucopolysaccharidosis have been reported, however, there is no published case of aortic valve replacements in two siblings with mucolipidosis.

Ocular Findings in Mucolipidosis Type II

PURPOSE: To report ocular findings of a mucolipidosis type II patient with novel mutation. CASE SUMMARY: A 10-year-old boy visited our pediatric genetic metabolic clinic for evaluation of his overall developmental delay and short stature. The boy was diagnosed with mucolipidosis type II (I-cell disease) using plasma enzyme assay and DNA sequencing of the GNPTAB gene mutation. An ophthalmologic investigation was then performed, and a depressed nasal bridge, broad nose, and swelling in the upper lid of both eyes were noted. The best corrected visual acuity was 0.32 and 0.1 and the intraocular pressure was 35 mmHg and 24 mmHg in the right and left eyes, respectively. The anterior chamber angles of both eyes were normal and mild cornea opacity in both eyes was observed. Fundus examination revealed retinal atrophy with folds in both eyes, as well as optic disc edema and optic atrophy in the right and left eyes, respectively. Atherosclerotic changes in the retinal vessels and cystoid macular edema in the left eye were observed, and ocular ultrasound revealed increased posterior sclera thickness in both eyes. CONCLUSIONS: Ocular manifestations of mucolipidosis type II are not currently well-known, and differentiation from other metabolic disorders may be difficult. An ophthalmic work-up can assist in diagnosis, and regular ophthalmic examinations should be used to maintain visual function in mucolipidosis patients.

Cryo-EM structures of the mammalian endo-lysosomal TRPML1 channel elucidate the combined regulation mechanism

TRPML1 channel is a non-selective group-2 transient receptor potential (TRP) channel with Ca permeability. Located mainly in late endosome and lysosome of all mammalian cell types, TRPML1 is indispensable in the processes of endocytosis, membrane trafficking, and lysosome biogenesis. Mutations of TRPML1 cause a severe lysosomal storage disorder called mucolipidosis type IV (MLIV). In the present study, we determined the cryo-electron microscopy (cryo-EM) structures of Mus musculus TRPML1 (mTRPML1) in lipid nanodiscs and Amphipols. Two distinct states of mTRPML1 in Amphipols are added to the closed state, on which could represent two different confirmations upon activation and regulation. The polycystin-mucolipin domain (PMD) may sense the luminal/extracellular stimuli and undergo a "move upward" motion during endocytosis, thus triggering the overall conformational change in TRPML1. Based on the structural comparisons, we propose TRPML1 is regulated by pH, Ca, and phosphoinositides in a combined manner so as to accommodate the dynamic endocytosis process.

Diagnostic Strategy for Mucolipidosis II/III.

Overlapping clinical phenotypes are a diagnostic challenge to the clinician, especially in the cases of mucolipidosis (ML) and mucopolysaccharide disorders (MPS), due to overlapping phenotypes. Present study was carried out in 147 children suspected to have ML or MPS and 100 controls. They were screened for ML II/III by colorimetric method using substrate pNCS. Six children were found screen positive for ML II/III and further confirmatory study showed significantly raised activity in plasma confirming high specificity of the ML screening test. Forty-two (28.5%) children out of remaining 141 children that were screen negative, were found to have various MPS disorders, while rest 99 had normal enzyme activity in plasma and leucocytes. Present study demonstrates prompt and specific chemical method that can be used as a tool for estimating ML II/III, with high specificity.

Severity score system for progressive myelopathy: development and validation of a new clinical scale

Progressive myelopathies can be secondary to inborn errors of metabolism (IEM) such as mucopolysaccharidosis, mucolipidosis, and adrenomyeloneuropathy. The available scale, Japanese Orthopaedic Association (JOA) score, was validated only for degenerative vertebral diseases. Our objective is to propose and validate a new scale addressing progressive myelopathies and to present validating data for JOA in these diseases. A new scale, Severity Score System for Progressive Myelopathy (SSPROM), covering motor disability, sphincter dysfunction, spasticity, and sensory losses. Inter- and intra-rater reliabilities were measured. External validation was tested by applying JOA, the Expanded Disability Status Scale (EDSS), the Barthel index, and the Osame Motor Disability Score. Thirty-eight patients, 17 with adrenomyeloneuropathy, 3 with mucopolysaccharidosis I, 3 with mucopolysaccharidosis IV, 2 with mucopolysaccharidosis VI, 2 with mucolipidosis, and 11 with human T-cell lymphotropic virus type-1 (HTLV-1)-associated myelopathy participated in the study. The mean ± SD SSPROM and JOA scores were 74.6 ± 11.4 and 12.4 ± 2.3, respectively. Construct validity for SSPROM (JOA: r = 0.84, P < 0.0001; EDSS: r = -0.83, P < 0.0001; Barthel: r = 0.56, P < 0.002; Osame: r = -0.94, P < 0.0001) and reliability (intra-rater: r = 0.83, P < 0.0001; inter-rater: r = 0.94, P < 0.0001) were demonstrated. The metric properties of JOA were similar to those found in SSPROM. Several clinimetric requirements were met for both SSPROM and JOA scales. Since SSPROM has a wider range, it should be useful for follow-up studies on IEM myelopathies.

A case of mucolipidosis II presenting with prenatal skeletal dysplasia and severe secondary hyperparathyroidism at birth / 소아과

Mucolipidosis II (ML II) or inclusion cell disease (I-cell disease) is a rarely occurring autosomal recessive lysosomal enzyme-targeting disease. This disease is usually found to occur in individuals aged between 6 and 12 months, with a clinical phenotype resembling that of Hurler syndrome and radiological findings resembling those of dysostosis multiplex. However, we encountered a rare case of an infant with ML II who presented with prenatal skeletal dysplasia and typical clinical features of severe secondary hyperparathyroidism at birth. A female infant was born at 37(+1) weeks of gestation with a birth weight of 1,690 g (T (p.Arg1031X) and c.3456_3459dupCAAC (p.Ile1154GlnfsX3), the latter being a novel mutation. The infant was treated with vitamin D supplements but expired because of asphyxia at the age of 2 months.

Oral findings in patients with mucolipidosis type III

Mucolipidosis type III is a rare, autosomal recessive disorder, which is part of a group of storage diseases as a result of inborn error of lysosomal enzyme metabolism. It is characterized by the gradual onset of signs and symptoms affecting the physical and mental development as well as visual changes, heart, skeletal and joint. Although oral findings associated with mucolipidosis type II have been extensively reported, there is a shortage of information on mucolipidosis type III. This paper presents radiological and histological findings of multiple radiolucent lesions associated with impacted teeth in the jaw of a 16 year-old youngster with mucolipidosis type III.

A mucolipidose tipo III é uma doença rara, autossômica recessiva, que faz parte de um grupo de doenças de depósito, decorrentes do erro inato do metabolismo das enzimas lisossômicas. Caracteriza-se pelo aparecimento progressivo de sinais e sintomas com repercussão no desenvolvimento físico e mental, bem como alterações visuais, cardíacas, esqueléticas e articulares. Apesar de achados bucais estarem bem relatados em associação à mucolipidose tipo II, esse artigo descreve achados radiográficos e histológicos de múltiplas lesões radiolúcidas, associadas a dentes inclusos nos maxilares, em uma jovem de 16 anos de idade com mucolipidose tipo III.

"Cherry red spot" in a patient with Tay-Sachs disease: case report / "Mácula em cereja" em paciente com doença de Tay-Sachs: relato de caso

Tay-Sachs disease is an autosomal recessive disorder of sphingolipid metabolism, caused by enzime hexosaminidase A deficiency that leads to an accumulation of GM2 in neurocytes which results in progressive loss of neurological function. The accumulation of lipid in retinal ganglion cells that leads to a chalk-white appearance of the fundus called "cherry red spot" is the hallmark of Tay-Sachs disease. It is also seen in others neurometabolic diseases as well as in central retinal artery occlusion. This case reports a child with Tay-Sachs disease in a family with four previous similar deaths without diagnostic.

Tay-Sachs é uma doença autossômica recessiva, caracterizada pela deficiência da enzima hexosaminidase A levando ao acúmulo de esfingolipídios (GM2) em células neuronais que resulta em uma perda progressiva da função neurológica. O acúmulo de lipídios em células ganglionais da retina leva a uma aparência de mácula em cereja, característica do fundo de olho de pessoas acometidas. "Mácula em cereja" também pode ser vista em outras doenças neurometabólicas e em oclusão da artéria central da retina. Este trabalho relata o caso de um paciente com doença de Tay-Sachs em uma família com história de quatro óbitos por causas semelhantes sem diagnóstico.

Mucopolysaccharidosis and mucolipidosis / 한양의대학술지

Mucopolysaccharidosis (MPS) and mucolipidosis(ML) belong to a group of rare genetic disorders of lysosomal enzymes and share some clinical manifestations. MPS is characterized by the accumulation of glycosaminoglycans (GAG) and results from the impaired function of one of 11 enzymes required for normal GAG degradation. ML, which is clinically similar to several forms of MPS, is caused by deficiency of Nacetylglucosamine-1-phosphotransferase activity. Therapeutic strategies for MPS, including enzyme replacement therapy and bone marrow transplantation, have been developed with some success. In this review, we discuss clinical feature, diagnostic methods, management and the present status of research on MPS and ML.