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BACKGROUND AND AIMS: Few studies have focused on the outcomes of Wilson's disease (WD) diagnosed before age of 5 years. This study aimed to summarize the clinical features of early diagnosed WD and analyse treatment outcomes and the risk factors associated with treatment failure. METHODS: A total of 139 children confirmed with WD before 5 years were enrolled in this study. Only patients with follow-up over 1 year were analysed with Kaplan-Meier survival analysis. The composite outcomes included death, progression to liver failure or acute hepatitis, development of renal or neurological symptoms and persistent elevation of alanine aminotransferase (ALT). The treatment failure was defined as occurrence of at least one of above outcomes. RESULTS: Among 139 WD patients at diagnosis, two (1.4%) WD patients presented with symptomatic liver disease, whereas 137 (98.6%) were phenotypically asymptomatic, including 135 with elevated ALT and 2 with normal liver function. Median serum ceruloplasmin (Cp) was 3.1 mg/dL, and urinary copper excretion was 87.4 µg/24-h. There were 71 variants identified in the the copper-transporting ATPase beta gene, and 29 were loss of function (LOF). 51 patients with LOF variant were younger at diagnosis and had lower Cp than 88 patients without LOF. Among 93 patients with over 1 year of follow-up, 19 (20.4%) received zinc monotherapy, and 74 (79.6%) received a zinc/D-penicillamine combination therapy. 14 (15.1%) patients underwent treatment failure, and its occurrence was associated with poor compliance (p < .01). CONCLUSIONS: Cp is a reliable biomarker for early diagnosis, and zinc monotherapy is an effective treatment for WD during early childhood. Good treatment compliance is critical to achieve a favourable outcome.
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BACKGROUND: Lowe syndrome is characterized by the presence of congenital cataracts, psychomotor retardation, and dysfunctional proximal renal tubules. This study presents a case of an atypical phenotype, investigates the genetic characteristics of eight children diagnosed with Lowe syndrome in southern China, and performs functional analysis of the novel variants. METHODS: Whole-exome sequencing was conducted on eight individuals diagnosed with Lowe syndrome from three medical institutions in southern China. Retrospective collection and analysis of clinical and genetic data were performed, and functional analysis was conducted on the five novel variants. RESULTS: In our cohort, the clinical symptoms of the eight Lowe syndrome individuals varied. One patient was diagnosed with Lowe syndrome but did not present with congenital cataracts. Common features among all patients included cognitive impairment, short stature, and low molecular weight proteinuria. Eight variations in the OCRL gene were identified, encompassing three previously reported and five novel variations. Among the novel variations, three nonsense mutations were determined to be pathogenic, and two patients harboring novel missense variations of uncertain significance exhibited severe typical phenotypes. Furthermore, all novel variants were associated with altered protein expression levels and impacted primary cilia formation. CONCLUSION: This study describes the first case of an atypical Lowe syndrome patient without congenital cataracts in China and performs a functional analysis of novel variants in the OCRL gene, thereby expanding the understanding of the clinical manifestations and genetic diversity associated with Lowe syndrome.
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Síndrome Oculocerebrorrenal , Fenotipo , Monoéster Fosfórico Hidrolasas , Humanos , Síndrome Oculocerebrorrenal/genética , Síndrome Oculocerebrorrenal/diagnóstico , Masculino , Femenino , Niño , Monoéster Fosfórico Hidrolasas/genética , China , Preescolar , Estudios Retrospectivos , Secuenciación del Exoma , Lactante , Adolescente , Mutación , Pueblo Asiatico/genética , Codón sin Sentido , Pueblos del Este de AsiaRESUMEN
Metachromatic leukodystrophy (MLD) is a rare hereditary neurodegenerative disease caused by deficiency of the lysosomal enzyme arylsulfatase A (ARSA). This study described the clinical and molecular characteristics of 24 Chinese children with MLD and investigated functional characterization of five novel ARSA variants. A retrospective analysis was performed in 24 patients diagnosed with MLD at Guangzhou Women and Children's Medical Center in South China. Five novel mutations were further characterized by transient expression studies. We recruited 17 late-infantile, 3 early-juvenile, 4 late-juvenile MLD patients. In late-infantile patients, motor developmental delay and gait disturbance were the most frequent symptoms at onset. In juvenile patients, cognitive regression and gait disturbance were the most frequent chief complaints. Overall, 25 different ARSA mutations were identified with 5 novel mutations.The most frequent alleles were p.W320* and p.G449Rfs. The mutation p.W320*, p.Q155=, p.P91L, p.G156D, p.H208Mfs*46 and p.G449Rfs may link to late-infantile type. The novel missense mutations were predicted damaging in silico. The bioinformatic structural analysis of the novel missense mutations showed that these amino acid replacements would cause severe impairment of protein structure and function. In vitro functional analysis of the six mutants, showing a low ARSA enzyme activity, clearly demonstrated their pathogenic nature. The mutation p.D413N linked to R alleles. In western blotting analysis of the ARSA protein, the examined mutations retained reduced amounts of ARSA protein compared to the wild type. This study expands the spectrum of genotype of MLD. It helps to the future studies of genotype-phenotype correlations to estimate prognosis and develop new therapeutic approach.
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Cerebrósido Sulfatasa , Leucodistrofia Metacromática , Humanos , Leucodistrofia Metacromática/genética , Cerebrósido Sulfatasa/genética , Femenino , Masculino , Preescolar , Niño , China/epidemiología , Lactante , Estudios Retrospectivos , Mutación/genética , Adolescente , Mutación MissenseRESUMEN
The SLC25A32 dysfunction is associated with neural tube defects (NTDs) and exercise intolerance, but very little is known about disease-specific mechanisms due to a paucity of animal models. Here, we generated homozygous (Slc25a32Y174C/Y174C and Slc25a32K235R/K235R) and compound heterozygous (Slc25a32Y174C/K235R) knock-in mice by mimicking the missense mutations identified from our patient. A homozygous knock-out (Slc25a32-/-) mouse was also generated. The Slc25a32K235R/K235R and Slc25a32Y174C/K235R mice presented with mild motor impairment and recapitulated the biochemical disturbances of the patient. While Slc25a32-/- mice die in utero with NTDs. None of the Slc25a32 mutations hindered the mitochondrial uptake of folate. Instead, the mitochondrial uptake of flavin adenine dinucleotide (FAD) was specifically blocked by Slc25a32Y174C/K235R, Slc25a32K235R/K235R, and Slc25a32-/- mutations. A positive correlation between SLC25A32 dysfunction and flavoenzyme deficiency was observed. Besides the flavoenzymes involved in fatty acid ß-oxidation and amino acid metabolism being impaired, Slc25a32-/- embryos also had a subunit of glycine cleavage system-dihydrolipoamide dehydrogenase damaged, resulting in glycine accumulation and glycine derived-formate reduction, which further disturbed folate-mediated one-carbon metabolism, leading to 5-methyltetrahydrofolate shortage and other folate intermediates accumulation. Maternal formate supplementation increased the 5-methyltetrahydrofolate levels and ameliorated the NTDs in Slc25a32-/- embryos. The Slc25a32K235R/K235R and Slc25a32Y174C/K235R mice had no glycine accumulation, but had another formate donor-dimethylglycine accumulated and formate deficiency. Meanwhile, they suffered from the absence of all folate intermediates in mitochondria. Formate supplementation increased the folate amounts, but this effect was not restricted to the Slc25a32 mutant mice only. In summary, we established novel animal models, which enabled us to understand the function of SLC25A32 better and to elucidate the role of SLC25A32 dysfunction in human disease development and progression.
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Ácido Fólico , Defectos del Tubo Neural , Animales , Humanos , Ratones , Carbono/metabolismo , Flavina-Adenina Dinucleótido/metabolismo , Ácido Fólico/metabolismo , Formiatos/metabolismo , Glicina/metabolismo , Mitocondrias/metabolismo , Defectos del Tubo Neural/genética , Defectos del Tubo Neural/metabolismoRESUMEN
BACKGROUND: Serum ceruloplasmin is one of the major diagnostic parameters for Wilson's disease (WD). Age and gender difference of serum ceruloplasmin remain controversy. This study aims to assess diagnostic value of serum ceruloplasmin level for WD in children up to age of 15 years. METHODS: Serum ceruloplasmin levels were measured in 317 WD patients, 21 heterozygotes, 372 healthy control children and 154 non-WD patients with other liver diseases. Receiver operating characteristic (ROC) curve was used to determine the diagnostic accuracy of serum ceruloplasmin for WD in children. RESULTS: Among healthy controls, serum ceruloplasmin level was slightly low in the infants younger than 6 months, and then maintained from 26 to 33 mg/dl after age of 6 months. A total of 8.1% of healthy children had levels of serum ceruloplasmin < 20 mg/dL. Serum ceruloplasmin level was 5.7 ± 4.7 mg/dl in WD patients, and 25.6 ± 5.9 mg/dl in heterozygous carriers. Only 1.9% of WD patients had serum ceruloplasmin levels > 20 mg/dL. Serum ceruloplasmin levels had gender difference, being higher in healthy boys than healthy girls, and higher in asymptomatic WD boys than asymptomatic WD girls (p < 0.01, p < 0.05). Serum ceruloplasmin levels also presented genotypic difference. WD patients with R778L homozygotes exhibited lower levels of serum ceruloplasmin than the patients without R778L (p < 0.05). The ROC curve revealed that serum ceruloplasmin level, at a cutoff value of 16.8 mg/dL, had the highest AUC value (0.990) with a sensitivity of 95.9% and a specificity of 93.6%. CONCLUSIONS: Serum ceruloplasmin is one of sensitive diagnostic biomarkers for WD in children. Gender and genotypic difference of serum ceruloplasmin level should be considered. The cutoff value of serum ceruloplasmin level < 16.8 mg/dL may provide the highest accuracy for diagnosis of WD in children.
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Ceruloplasmina , Degeneración Hepatolenticular , Adolescente , Niño , Cobre/metabolismo , Femenino , Degeneración Hepatolenticular/diagnóstico , Heterocigoto , Humanos , Lactante , Masculino , Curva ROCRESUMEN
BACKGROUND: Pathogenic mutations in the PHKG2 are associated with a very rare disease-glycogen storage disease IXc (GSD-IXc)-and are characterized by severe liver disease. CASE PRESENTATION: Here, we report a patient with jaundice, hypoglycaemia, growth retardation, progressive increase in liver transaminase and prominent hepatomegaly from the neonatal period. Genetic testing revealed two novel, previously unreported PHKG2 mutations (F233S and R320DfsX5). Functional experiments indicated that both F223S and R320DfsX5 lead to a decrease in key phosphorylase b kinase enzyme activity. With raw cornstarch therapy, hypoglycaemia and lactic acidosis were ameliorated and serum aminotransferases decreased. CONCLUSION: These findings expand the gene spectrum and contribute to the interpretation of clinical presentations of these two novel PHKG2 mutations.
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Enfermedad del Almacenamiento de Glucógeno , Hipoglucemia , Enfermedad del Almacenamiento de Glucógeno/diagnóstico , Enfermedad del Almacenamiento de Glucógeno/genética , Enfermedad del Almacenamiento de Glucógeno/patología , Humanos , Recién Nacido , Hígado/patología , Mutación , Fosforilasa Quinasa/genéticaRESUMEN
Wilson disease (WD) is a rare autosomal recessive disorder caused by mutations in the ATP7B gene. Clinical features and mutational analysis of Chinese children with WD at early age were rarely described. Herein, we retrospectively examined 114 children with WD at the mean of 5.9 years old age at diagnosis. Eight patients developed acute liver failure at mean age of 9.7 years old, 4 of whom died. Among the 114 patients, 86.0% were presymptomatic with isolated elevation of transaminases at diagnosis, 99.1% had decreased ceruloplasmin, and 68.4% had urinary copper excretion over 100 µg/24 hr. Bi-allele pathogenic ATP7B mutations were identified in all patients. Among the 60 mutations detected, 10 were novel, including 7 missense mutations (p.I566N, p.T704I, p.C980F, p.G1030 V, p.A1096Q, p.L1327P, and p.L1373F), 1 nonsense mutation (p.K866X), 1 small insertion (p.Y44LfsX2), and 1 small deletion (p.R1118PfsX10). The most frequent mutations were p.R778L, p.P992L, and p.I1148T, which affected 27.2, 25.4, and 20.2% of the 114 WD children, respectively. The patients carrying p.R778L presented a higher rate of acute liver failure than the patients without p.R778L (9.7% vs. 4.8%). These results will be helpful in establishing early diagnosis of WD at the gene level, offering beneficial information for genetic counseling and providing clues to genotype/phenotype correlation of ATP7B mutations.
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ATPasas Transportadoras de Cobre/genética , Degeneración Hepatolenticular/genética , Fallo Hepático Agudo/genética , Hígado/metabolismo , Mutación , Adolescente , Enfermedades Asintomáticas , Biomarcadores/sangre , Ceruloplasmina/metabolismo , Niño , Preescolar , China , Cobre/orina , Análisis Mutacional de ADN , Femenino , Expresión Génica , Degeneración Hepatolenticular/diagnóstico , Degeneración Hepatolenticular/mortalidad , Degeneración Hepatolenticular/patología , Humanos , Hígado/patología , Fallo Hepático Agudo/diagnóstico , Fallo Hepático Agudo/mortalidad , Fallo Hepático Agudo/patología , Masculino , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Análisis de Supervivencia , Transaminasas/sangreRESUMEN
OBJECTIVE: Hypophosphatasia (HPP) is an inherited disorder of defective skeletal mineralization caused by mutations in the ALPL gene that encodes the Tissue Non-specific Alkaline Phosphatase (TNSALP). It is subdivided into six forms depending on the age of onset: perinatal lethal, prenatal benign, infantile, childhood, adult, and odonto HPP. Among these, infantile HPP is characterized by early onset and high frequency of lethal outcome. Few studies have reported the phenotype and genetic characteristics of HPP in Chinese children. CASE PRESENTATION: Three forms of HPP were identified in four unrelated patients from four different Chinese families, including one lethal infantile (patient 1), two childhood (patient 2 and 3) and one odonto HPP (patient 4). Six variants in the ALPL gene were identified, including five missense mutations and one frameshift mutation. Of which, none were reported previously in the Chinese population, and two were novel (c.359G > C: p.G120A and c.1017dupG: p.H340AfsX3). Patient 1 carrying a novel homozygous (c.359G > C) mutation showed respiratory distress and pneumonia at first day of his life. He presented nearly negligible level of serum ALP activity, overall skeletal hypominaralization and died at 3 months old. Patient 2, 3 and 4 were compound heterozygotes with decreased serum ALP activity. Patient 2 and 3 presented premature loss of deciduous teeth, muscle weakness and bone pain, whereas patient 4 had early loss of deciduous teeth only. All four pedigrees exhibited autosomal recessive pattern of inheritance. CONCLUSIONS: In this study, six mutations in the ALPL gene were found in four Chinese HPP patients, two of which were novel: c.359G > C in exon 5 and c.1017dupG in exon 10. Our results strongly indicated that the novel mutation c.359G > C might be disease-causing and associated with severe infantile form of HPP.
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Fosfatasa Alcalina/genética , Hipofosfatasia/genética , Mutación , Pueblo Asiatico , Niño , Preescolar , Femenino , Humanos , Lactante , MasculinoRESUMEN
Gaucher disease (GD) is a common lysosomal storage disorder caused by the deficiency of acid ß-glucosidase, due to mutations in the GBA gene. To explore the clinical and molecular characteristics of GD patients from Southern China, GBA gene were analyzed by nest PCR and direct Sanger-sequencing. Novel missense mutations were transiently transfected in COS-7 cells by plasmid system for functional verification. Among the 22 GD patients, 19 patients were classified as type 1 and three as type 2. Over 60% of the type 1 patient had the onset before two years of age and about 42% of them died before three years of age. Six type 1 patients with L444P homozygous genotype, presented with early onset and severe hepatosplenomegaly. Four novel mutations Y22C, F109L, L149F and c.983_990delCCCACTGG were identified. The GBA activities in vitro of novel mutants Y22C, F109L and L149F were 20.2%, 6.9% and 6.5% of the wild-type, respectively. L444P mutation accounted for 47.7% of the mutant alleles. Our results revealed that type 1 GD tends to present with a severe phenotype among southern Chinese. L444P was the most prevalent mutation and L444P homozygous genotype was associated with severe type 1 GD. Three novel missense mutations identified were pathogenic.
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Enfermedad de Gaucher/genética , Glucosilceramidasa/genética , Mutación , Adolescente , Adulto , Anciano , Animales , Pueblo Asiatico/genética , Células COS , Niño , Preescolar , China/epidemiología , Chlorocebus aethiops , Femenino , Enfermedad de Gaucher/epidemiología , Genotipo , Glucosilceramidasa/química , Homocigoto , Humanos , Lactante , Masculino , Persona de Mediana Edad , Modelos Moleculares , Mutación Missense , Mutación Puntual , Conformación Proteica , Adulto JovenRESUMEN
OBJECTIVE: To report the 4-year experience of early prenatal diagnosis of lysosomal storage disorders (LSDs) at a center in mainland China. METHOD: Forty-seven pregnancies affected with LSDs were assed using enzymes and/or molecular studies. Prenatal studies were performed on 43 uncultured chorionic villi (CV) samples, two amniotic fluid samples, and two umbilical cord blood samples. RESULTS: Of the 47 fetuses, 23 (48.9%) were determined to normal, 13 (27.7%) to be carriers, and 11 (23.4%) diagnosed as affected. In this cohort, mucopolysaccharidoses (MPS) type II was the most common LSD, followed by Pompe disease and then metachromatic leucodystrophy. In the 17 MPS II cases, the four affected fetuses showed MPS II enzyme activity expression levels of 1.4% to 6.7%, while the enzyme activity levels of the 13 normal fetuses ranged from 72% to 240.4%. In the seven Pompe cases, three fetuses were normal with Pompe enzyme activity expression levels of 20%, 38.8%, and 77.3%, while four carrier pregnancies showed enzyme activity levels of 17.5%, 17.5%, 33.4%, and 13.8%, respectively. CONCLUSION: Based on different enzyme properties in uncultured CV, different prenatal diagnostic strategies should be adopted for MPS II and Pompe disease. Combining enzyme assay and molecular studies in uncultured CV improves the reliability of prenatal diagnosis of LSDs.
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Muestra de la Vellosidad Coriónica/estadística & datos numéricos , Enfermedades por Almacenamiento Lisosomal/diagnóstico , Adulto , Femenino , Humanos , Enfermedades por Almacenamiento Lisosomal/enzimología , Embarazo , Adulto JovenRESUMEN
BACKGROUND: There is scarcity of information on the clinical features and genetics of glucokinase-maturity-onset diabetes of the young (GCK-MODY) in China. The aim of the study was to investigate the clinical and molecular characteristics of Chinese children with GCK-MODY. METHODS: Eleven children with asymptomatic hyperglycemia and clinically suspected GCK-MODY were identified from the database of children with diabetes in the biggest children's hospital in South China. Clinical data were obtained from medical records. Blood was collected from the patients and their parents for glucokinase (GCK) gene analysis. Parents without diabetes were tested for fasting glucose and HbA1c. Clinical information and blood for GCK gene analysis were obtained from grandparents with diabetes. GCK gene mutational analysis was performed by polymerase chain reaction and direct sequencing. Patients without a GCK gene mutation were screened by targeted next-generation sequencing (NGS) technology for other MODY genes. RESULTS: Nine children tested positive for GCK gene mutations while two were negative. The nine GCK-MODY patients were from unrelated families, aged 1 month to 9 years and 1 month at first detection of hyperglycaemia. Fasting glucose was elevated (6.1-8.5 mmol/L), HbA1c 5.2-6.7% (33.3-49.7 mmol/mol), both remained stable on follow-up over 9 months to 5 years. Five detected mutations had been previously reported: p.Val182Met, c.679 + 1G > A, p.Gly295Ser, p.Arg191Gln and p.Met41Thr. Four mutations were novel: c.483 + 2 T > A, p.Ser151del, p.Met57GlyfsX29 and p.Val374_Ala377del. No mutations were identified in the other two patients, who were also tested by NGS. CONCLUSIONS: GCK gene mutations are detected in Chinese children and their family members with typical clinical features of GCK-MODY. Four novel mutations are detected.
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Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/genética , Glucoquinasa/genética , Niño , Preescolar , China , Análisis Mutacional de ADN , Femenino , Estudios de Seguimiento , Marcadores Genéticos , Humanos , Lactante , Masculino , Mutación , PronósticoRESUMEN
Maple syrup urine disease (MSUD) is a rare autosomal recessive genetic disorder caused by defects in the catabolism of the branched-chain amino acids (BCAAs). Classic form of MSUD (CMSUD) is caused by mutations in BCKDHA, BCKDHB, DBT genes mostly. In this study, we analyzed the clinical and genetic characteristics of two patients with CMSUD. Two homozygous mutations, c.517G > T (p.Asp173Tyr) and c.503G > A (p.Arg168His), both in the exon 5 of BCKDHB were detected respectively. The novel mutation p.Asp173Tyr of patient A, inherited from his parents, is predicted to affect conformation of protein by computer analysis. The reported mutation p.Arg168His observed in patient B seemed to occur in a maternal uniparental disomy inheritance manner. Review of related literature revealed that most missense mutations in exon 5 of BCKDHB in homozygous genotype often result in CMSUD because of its incorrect conformation, and exon 5 of BCKDHB might be a susceptible region. Thus the novel homozygous mutation p.Asp173Tyr and the founder homozygous mutation p.Arg168His may be responsible for the clinical presentation of the two CMSUD patients, facilitating the future genetic counselling and prenatal diagnosis.
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3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida)/genética , Exones/genética , Homocigoto , Enfermedad de la Orina de Jarabe de Arce/diagnóstico por imagen , Enfermedad de la Orina de Jarabe de Arce/genética , Mutación Missense/genética , Resultado Fatal , Humanos , Lactante , Recién Nacido , MasculinoRESUMEN
Fucosidosis is a rare lysosomal storage disease caused by α-fucosidase deficiency, which leads to progressive neurological deterioration and death. Hematopoietic stem cell transplantation is the best curative therapy if performed during the early stages of disease. We report two fucosidosis patients with brain abnormalities and the challenge faced in their management. The first patient received supportive therapy and the second one firstly underwent unrelated donor umbilical cord blood transplantation. After a period of follow-up, we found neurological symptoms were worsening day by day on patient1. By contrast, patient2 who received cord blood transplantation acquired clinical neurologic improvement in response to normalization of deficient enzymatic activity. This report indicates that hematopoietic transplant could reduce the severity and retard the progression of clinical neurological deterioration. Umbilical cord blood transplantation is a novel approach for treating fucosidosis patients who lack suitable bone morrow donors.
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Encéfalo/patología , Trasplante de Células Madre de Sangre del Cordón Umbilical/métodos , Fucosidosis/patología , Fucosidosis/terapia , Trasplante de Células Madre Hematopoyéticas/métodos , Atrofia , Encéfalo/diagnóstico por imagen , Preescolar , Discapacidades del Desarrollo/diagnóstico por imagen , Discapacidades del Desarrollo/etiología , Progresión de la Enfermedad , Femenino , Fucosidosis/diagnóstico por imagen , Humanos , Lactante , Masculino , Resultado del TratamientoRESUMEN
Phosphodiesterase-9 (PDE9) inhibitors have been studied as potential therapeutics for treatment of central nervous system diseases and diabetes. Here, we report the discovery of a new category of PDE9 inhibitors by rational design on the basis of the crystal structures. The best compound, (S)-6-((1-(4-chlorophenyl)ethyl)amino)-1-cyclopentyl-1,5,6,7-tetrahydro-4H-pyrazolo[3,4-day]pyrimidin-4-one [(S)-C33], has an IC50 value of 11 nM against PDE9 and the racemic C33 has bioavailability of 56.5% in the rat pharmacokinetic model. The crystal structures of PDE9 in the complex with racemic C33, (R)-C33, and (S)-C33 reveal subtle conformational asymmetry of two M-loops in the PDE9 dimer and different conformations of two C33 enantiomers. The structures also identified a small hydrophobic pocket that interacts with the tyrosyl tail of (S)-C33 but not with (R)-C33, and is thus possibly useful for improvement of selectivity of PDE9 inhibitors. The asymmetry of the M-loop and the different interactions of the C33 enantiomers imply the necessity to consider the whole PDE9 dimer in the design of inhibitors.
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3',5'-AMP Cíclico Fosfodiesterasas/antagonistas & inhibidores , 3',5'-AMP Cíclico Fosfodiesterasas/química , Inhibidores de Fosfodiesterasa/química , Secuencia de Aminoácidos , Animales , Disponibilidad Biológica , Diseño de Fármacos , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Masculino , Datos de Secuencia Molecular , Inhibidores de Fosfodiesterasa/farmacocinética , Multimerización de Proteína , Ratas , Ratas Sprague-Dawley , EstereoisomerismoRESUMEN
Dopa and tetrahydrobiopterin (BH4) supplementation are recommended therapies for the dopa-responsive dystonia caused by GTP cyclohydrolase 1 (GCH1, also known as GTPCH) deficits. However, the efficacy and mechanisms of these therapies have not been intensively studied yet. In this study, we tested the efficacy of dopa and BH4 therapies by using a novel GTPCH deficiency mouse model, Gch1KI/KI, which manifested infancy-onset motor deficits and growth retardation similar to the patients. First, dopa supplementation supported Gch1KI/KI mouse survival to adulthood, but residual motor deficits and dwarfism remained. Interestingly, RNAseq analysis indicated that while the genes participating in BH4 biosynthesis and regeneration were significantly increased in the liver, no significant changes were observed in the brain. Second, BH4 supplementation alone restored the growth of Gch1KI/KI pups only in early postnatal developmental stage. High doses of BH4 supplementation indeed restored the total brain BH4 levels, but brain dopamine deficiency remained. While total brain TH levels were relatively increased in the BH4 treated Gch1KI/KI mice, the TH in the striatum were still almost undetectable, suggesting differential BH4 requirements among brain regions. Last, the growth of Gch1KI/KI mice under combined therapy outperformed dopa or BH4 therapy alone. Notably, dopamine was abnormally high in more than half, but not all, of the treated Gch1KI/KI mice, suggesting the existence of variable synergetic effects of dopa and BH4 supplementation. Our results provide not only experimental evidence but also novel mechanistic insights into the efficacy and limitations of dopa and BH4 therapies for GTPCH deficiency.
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Biopterinas/análogos & derivados , Dihidroxifenilalanina , Dopamina , Fenilcetonurias , Humanos , Ratones , Animales , GTP Ciclohidrolasa/genética , Modelos Animales de EnfermedadRESUMEN
BACKGROUND: Glycogen storage disease type Ib (GSD Ib) is a rare disorder characterized by impaired glucose homeostasis caused by mutations in the SLC37A4 gene. It is a severe inherited metabolic disease associated with hypoglycemia, hyperlipidemia, lactic acidosis, hepatomegaly, and neutropenia. Traditional treatment consists of feeding raw cornstarch which can help to adjust energy metabolism but has no positive effect on neutropenia, which is fatal for these patients. Recently, the pathophysiologic mechanism of the neutrophil dysfunction and neutropenia in GSD Ib has been found, and the treatment with the SGLT2 inhibitor empaglifozin is now well established. In 2020, SGLT2 inhibitor empagliflozin started to be used as a promising efficient remover of 1,5AG6P in neutrophil of GSD Ib patients worldwide. However, it is necessary to consider long-term utility and safety of a novel treatment. RESULTS: In this study, we retrospectively examined the clinical manifestations, biochemical examination results, genotypes, long-term outcomes and follow-up of thirty-five GSD Ib children who visited our department since 2009. Fourteen patients among them underwent empagliflozin treatment since 2020. This study is the largest cohort of pediatric GSD Ib patients in China as well as the largest cohort of pediatric GSD Ib patients treated with empagliflozin in a single center to date. The study also discussed the experience of long-term management on pediatric GSD Ib patients. CONCLUSION: Empagliflozin treatment for pediatric GSD Ib patients is efficient and safe. Increase of urine glucose is a signal for pharmaceutical effect, however attention to urinary infection and hypoglycemia is suggested.
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Compuestos de Bencidrilo , Enfermedad del Almacenamiento de Glucógeno Tipo I , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Niño , Humanos , Antiportadores , Estudios de Seguimiento , Glucosa , Glucósidos , Enfermedad del Almacenamiento de Glucógeno Tipo I/tratamiento farmacológico , Hipoglucemia , Proteínas de Transporte de Monosacáridos/genética , Neutropenia , Estudios Retrospectivos , Inhibidores del Cotransportador de Sodio-Glucosa 2/uso terapéuticoRESUMEN
Phosphodiesterase-4D (PDE4D) has been proved to be a potential therapeutic target against strokes. In the present study, a procedure of integrating pharmacophore, molecular docking, molecular dynamics (MD) simulations, binding free energy calculations, and finally validation with bioassay was developed and described to search for novel PDE4D inhibitors from the SPECS database. Among the 29 compounds selected by our MD-augmented strategy, 15 hits were found with IC50 between 1.9 and 50 µM (a hit rate of 52%) and 6 potent hits showed IC50 less than 10 µM, which suggested that MD simulations can explore the intermolecular interactions of PDE4D-inhibitor complexes more precisely and thus significantly enhanced the hit rate of this screening. The effective and efficient integrated procedures described in this study could be readily applied to screening studies toward other drug targets.
Asunto(s)
Fosfodiesterasas de Nucleótidos Cíclicos Tipo 4/química , Descubrimiento de Drogas , Simulación del Acoplamiento Molecular , Inhibidores de Fosfodiesterasa/química , Relación Estructura-Actividad Cuantitativa , Dominio Catalítico , Bases de Datos de Compuestos Químicos , Pruebas de Enzimas , Escherichia coli/genética , Humanos , Cinética , Ligandos , Simulación de Dinámica Molecular , Unión Proteica , Proteínas Recombinantes/química , TermodinámicaRESUMEN
OBJECTIVES: To find biochemical and molecular markers can assist in identifying serious liver damage of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) patients. METHODS: 138 patients under 13 days to 1.1 year old diagnosed of NICCD in our center from 2004 to 2020. Base on the abnormal liver laboratory tests, we divided 138 patients into three groups: acute liver failure (ALF), liver dysfunction, and non-liver dysfunction groups, then compared their clinical, biochemical and, molecular data. RESULTS: 96â¯% of 138 patients had high levels of citrulline and high ratio of threonine to serine, which is the distinctive feature of plasma amino acid profile for NICCD. A total of 18.1â¯% of 138 patients had evidence of ALF who presented the most severity hepatic damage, 51.5â¯% had liver dysfunction, and the remaining 30.4â¯% presented mild clinical symptoms (non-liver dysfunction). In ALF group, the levels of citrulline, tyrosine, TBIL, ALP, and γ-GT was significantly elevated, and the level of ALB and Fisher ratio was pronounced low. Homozygous mutations of 1,638_1660dup, IVS6+5G.A, or IVS16ins3kb in SLC25A13 gene were only found in ALF and liver dysfunction groups. Supportive treatment including medium-chain triglyceride supplemented diet and fresh frozen plasma could be life-saving and might reverse ALF. CONCLUSIONS: High level of citrulline, tyrosine, TBIL, ALP, γ-GT, and ammonia, low level of albumin, and low Fisher ratio were predictors to suggest severe liver damage in NICCD patients who may go on to develop fatal metabolic disorder. Early identification and proper therapy is particularly important for these patients.
Asunto(s)
Citrulinemia , Enfermedades del Recién Nacido , Hepatopatías , Humanos , Lactante , Recién Nacido , Colestasis Intrahepática/genética , Citrulina , Citrulinemia/genética , Citrulinemia/diagnóstico , Pueblos del Este de Asia , Proteínas de Transporte de Membrana Mitocondrial/genética , Mutación , Tirosina , Hepatopatías/genéticaRESUMEN
OBJECTIVES: Congenital generalized lipodystrophy (CGL) is a group of rare autosomal inherited diseases characterized by a widespread loss of adipose tissue. The main purpose of this study was to evaluate the features of Chinese patients with CGL2. METHODS: Three patients diagnosed with CGL2 from our center were reviewed. Data on clinical features, results of laboratory analyses, and previous treatments were retrospectively collected. This study also reviewed studies that reported patients diagnosed with CGL2 in the last 30 years. RESULTS: All patients presented a lack of subcutaneous fat, hypertriglyceridemia, reversed triangular faces, acanthosis nigricans, and hepatomegaly within the first six months of life. All three patients developed splenomegaly, and mental retardation in later life. Dietary control dramatically lowered triglyceride levels in all patients. One patient presented with diabetes mellitus at 1 year-old. Although combined therapy with low fat diet and metformin maintained normal levels of blood lipid and glucose, this patient developed hypertrophic cardiomyopathy at the age of three. By a literature review on all Chinese cases with CGL2, it is known that classic manifestations such as hypertriglyceridemia, hepatomegaly and diabetes mellitus can occur shortly after birth, and early diagnosis and treatment can improve quality of life. In this cohort, the most frequent variations are c.782dupG and c.974dup in the BSCL2 gene. However, the same genotype may have different clinical phenotypes in patients with CGL2. CONCLUSIONS: This study not only described the clinical and genetic features of three patients with CGL2 in China, but also reviewed literature about CGL2 around the world.