Analysis of gene variation and long-term follow-up in children with phenylalanine hydroxylase deficiency diagnosed by newborn screening / 浙江大学学报·医学版

OBJECTIVES@#To retrospectively analyze the variation and characteristics of phenylalanine hydroxylase (PAH) gene, and to observe the long-term treatment effect and follow-up of newborns with PAH deficiency.@*METHODS@#Clinical data, treatment and follow-up results of 198 patients with PAH deficiency diagnosed by newborn screening in Jinan from 1996 to 2021 were collected. The genetic analysis of 55 patients with PAH deficiency diagnosed by newborn screening in Jinan and 213 patients referred from the surrounding areas of Jinan were summarized. Gene variations were checked by a customized Panel gene detection method. Blood phenylalanine-concentration and physical development indicators including height and weight were regularly monitored. Intellectual development was assessed using a neuropsychological development scale for patients aged 0-6 years and academic performance, and brain injury in patients was assessed using brain magnetic resonance imaging.@*RESULTS@#c.728G>A, c.158G>A, c.721C>T, c.1068C>A, c.611A>G variations were common in PAH gene. The genotype of c.158G>A variation is compound heterozygous variation, with mainly a mild hyperpheny-lalaninemia. 168 patients with PAH deficiency who were followed-up regularly had normal physical development without dwarfism or malnutrition. Among the 33 preschool patients who underwent mental development assessment, 2 were mentally retarded and the initial treatment age was older than 6 months. Nine patients with an average age of (17.13±2.42) years completed brain magnetic resonance imaging, one case was normal, and 8 cases were abnormal. There were patchy or patchy hyperintense foci near the bilateral lateral ventricles on T2WI, and the intellectual development was normal. Compared with the other eight patients, the blood phenylalanine concentration of the normal child was better and stably controlled within the ideal range.@*CONCLUSIONS@#c.728G>A, c.158G>A, c.721C>T, c.1068C>A, c.611A>G variations were common in PAH gene. After standardized treatment, most patients with PAH deficiency diagnosed by screening can obtain normal growth and intellectual development in adolescence, but there are different degrees of organic lesions in the cerebral white matter.

Age-related changes in liver functional reserve measured by the L-1- 13C-phenylalanine breath test / 中华老年医学杂志

Objective:To evaluate liver functional reserve in healthy subjects of different age groups using the L-[1- 13C]-phenylalanine breath test( 13C-pheBT)and to investigate the patterns of changes in liver functional reserve with aging in comparison with elderly cirrhosis patients. Methods:Thirty-seven healthy volunteers were divided into a young and middle-aged group(n=10), an early elderly group(n=9), an advanced elderly group(n=9)and a longevity group(n=9). Eight elderly patients with liver cirrhosis were selected as the control group.An oral dose of 100 mg 13C-phe was administered to each subject.Expired breath samples were collected at pre-dose and at 12 different time points within 150 minutes post-dose.Isotope ratio mass spectrometer was used to measure the abundance of 13C.The percentage of the 13C excretion rate( 13CO 2ERt), the percentage of 13C cumulative excretion( 13Ccumt)at different time points, and the percentage of the 13C peak excretion rate( 13CO 2ERmax)after drug administration were calculated.In addition, associations between 13C-pheBT and common liver function parameters were analyzed. Results:Compared with healthy volunteers, 13CO 2ER 30, 13CO 2ER 45, 13CO 2ER 60, 13Ccum 45, 13Ccum 60, 13Ccum 75, 13Ccum 90 and 13Ccum 105, 13Ccum 120, 13Ccum 135, 13Ccum 150 showed significant differences in the longevity group, the young and middle-aged group and the young elderly group.There were statistically significant differences between the elderly cirrhosis group and the healthy volunteers in each subgroup(all P<0.05); The mean values of 13CO 2ERmax, 13CO 2ER 30, 13Ccum 45, 13Ccum 60, 13Ccum 75, 13Ccum 90, 13Ccum 105, 13Ccum 120, 13Ccum 135, 13Ccum 150 decreased following the order of the young and middle-aged group, the early elderly group, the advanced elderly group, the longevity group, and the elderly cirrhosis group(all P<0.05). In healthy volunteers, the 13CO 2 exclusion rate curve and the cumulative exclusion rate curve showed that the curves of the young and middle-aged group and the early elderly group almost overlapped, while the curves of the advanced group and the longevity group decreased with age, and the difference between the longevity group and the young and middle-aged group and between the longevity group and the early elderly group was markedly prominent. Conclusions:13C-pheBT is a safe, sensitive and reliable test for quantitation of liver function.Our recommendations include collecting samples within an hour of drug administration and using 13CO 2ERmax, 13CO 2ER 30, 13Ccum 45 and 13Ccum 60 as the main parameters.Overall, the functional reserve and compensatory capability of the liver are robust.The decline in liver functional reserve in healthy individuals is a gradual and slow process, with a significant decrease after age 80 and more so after age 90.

Genetic profiles of phenylalanine hydroxylase gene mutations in neonates with phenylketonuria in Xinjiang / 中国新生儿科杂志

Objective:To study the genetic profiles of phenylalanine hydroxylase (PAH) gene mutations in neonates with phenylketonuria (PKU) in Xinjiang.Methods:From January 2015 to December 2021,neonates born and genetically diagnosed with PKU in our region were retrospectively included. The genetic profiles of different ethnic groups were analyzed and compared with PKU patients from central, northwest and northern regions of China.Results:A total of 131 neonates with PKU were enrolled, including 82 Han, 25 Hui and 20 Uyghur patients, 4 cases of other ethnic groups. 46, 20 and 14 types of pathogenic variants were detected in each ethnic group with detection rates of 95.1% (156/164), 66.0% (33/50), and 60.0% (24/40), respectively. The variants were mainly missense mutations and located in exons 2, 3, 6,7 and 11. The most common loci in Hui patients were c.158G>A (18.2%), c.728G>A (18.2%) and c.898G>T (9.1%). The most common loci in Uyghur patients were c.158G>A (33.3%), c.355C>T (12.5%) and c.1068C>A (8.3%). c. 898G>T might be most unique in Hui patients and c.355C>T most unique in Uyghur patients in Xinjiang. A novel variant of PAH gene, c.828G>C (p.M276I) in exon 7 was identified. Compared with northern, central and northwestern regions of China, PKU patients in Xinjiang had significantly higher incidence of c.158G>A mutation and lower incidence of c.728G>A mutation ( P<0.05). Conclusions:Missense mutations of PAH gene are common in some regions of Xinjiang. The compositions of PAH gene variations are similar to northwest and northern China with significant differences in hotspots of mutations.

Gene cloning and enzymatic activity analysis of phenylalanine ammonia-lyase from Sinopodophyllum hexandrum (Royle) Ying / 生物工程学报

Phenylalanine ammonia-lyase (PAL) is the key entry enzyme of plant phenylpropanoid pathway. It plays an important role in the biosynthesis of podophyllotoxin, an anti-tumor lignan that is currently produced from its main natural source Sinopodophyllum hexandrum (Royle) Ying. In this study, we cloned the gene ShPAL encoding phenylalanine ammonia-lyase by RT-PCR from the root of S. hexandrum ecotype inhabited in the Aba' district, Sichuan, based on its public SRA transcriptome data-package. Bioinformatics analyses showed that the ShPAL-encoded protein is composed of 711 amino acids, contains the conserved domains of PAL, and has the signature motif within the active center of aromatic ammonia-lyases. Moreover, ShPAL protein was predicted to have a secondary structure mainly composed of α-helix and random coil, a typical 'seahorse' shape monomer tertiary structure, and a homologous tetramer three-dimensional structure by Swiss-Modelling. The phylogenetic lineage analysis indicated ShPAL was of the highest sequence identity and the shortest evolutionary distance with the PAL of Epimedium sagittatum from the same Berberidaceae family. Subcellular localization experiments showed that ShPAL protein was mainly distributed in the cytoplasm, despite of a minority on the endoplasmic reticulum membrane. Furthermore, ShPAL protein was recombinantly expressed in Escherichia coli and purified by histidine-tag affinity chromatography. Its enzymatic activity was determined up to 20.91 U/mg, with the optimum temperature of 41 ℃ and pH of 9.0. In contrast, the enzyme activity of its F130H mutant decreased by about 23.6%, yet with the same trends of change with temperature and pH, confirming that phenylalanine at this position does affect the substrate specificity of PAL. Both the wild type and the mutant have relatively poor thermostability, but good pH-stability. These results may help to further investigate the regulatory role of PAL in the process of podophyllotoxin biosynthesis and advance the heterologous synthesis of podophyllotoxin to protect the germplasm resource of S. hexandrum. They also demonstrate that ShPAL has a potential application in biochemical industry and biomedicine.

Physical, intellectual and genetic characteristics of 53 neonates with phenylketonuria / 预防医学

Objective@#To investigate the physical and intellectual development and mutation characteristics of the phenylalanine hydroxylase (PAH) gene among 53 newborns with phenylketonuria (PKU), so as to provide insights into the management and genetic counseling of PKU@*Methods@#The medical records of 54 children with definitive diagnosis of PKU and standardized therapy until 2 years at the Center for Neonatal Disease Screening of Shanxi Children' s Hospital from 2018 to 2021 were collected. Newborns' body weight and height developments were evaluated using the World Health Organization growth chart (2006 version), and the intellectual development was assessed using the national criteria of Development Behavior Assessment Scale among Children at Ages of 0 to 6 Years (WS/T 580-2017). The gene mutations were detected among neonates and their children, and the physical, intellectual developments and genetic characteristics of neonates with PKU were descriptively analyzed.@*Results@#The 53 PKU cases included 29 male children and 24 female children, 36 cases with classic PKU and 17 cases with mild PKU, and 30 cases from rural areas and 23 cases from urban areas. The study subjects had a median age of 30 (10) d at initial therapy, and a mean blood phenylalanine concentration of (1 507±685) μmol/L at definitive diagnosis. There were 52 cases with normal height developments (98.11%), and all cases had normal weight and intellectual developments. The mean developmental functional quotient (DFQ) was significantly greater among urban children with PKU than among rural children [(94.92±8.57) vs. (87.65±6.57); t=-3.498, P=0.001], and the mean DFQ was significantly higher among children with mild PKU than among those with classic PKU [(95.55±8.76) vs. (88.57±7.11); t=-3.095, P=0.003]. There were 37 mutations detected in the PAH gene, which were mainly distributed in exons 3, 6, 7, 11, 12 and intron 4. Three high-frequency mutation sites were detected, including c.728G>A, c.611A>G and c.1197A>T, including three novel mutations (c.674C>G, c.1316-2A>C and c.1069T>C).@*Conclusions@#Following standardized treatment, the children with PKU have comparable physical and intellectual developments as compared to normal children. c.728G>A, c.611A>G and c.1197A>T were predominant mutations in the PAH gene among these 53 children with PKU, and three novel mutations were identified, including c.674C>G, c.1316-2A>C and c.1069T>C.

Molecular cloning and characterization of three phenylalanine ammonia-lyase genes from Schisandra chinensis / 中国天然药物

Phenylalanine ammonia-lyase (PAL), which catalyzes the conversion from L-phenylalanine to trans-cinnamic acid, is a well-known key enzyme and a connecting step between primary and secondary metabolisms in the phenylpropanoid biosynthetic pathway of plants and microbes. Schisandra chinensis, a woody vine plant belonging to the family of Magnoliaceae, is a rich source of dibenzocyclooctadiene lignans exhibiting potent activity. However, the functional role of PAL in the biosynthesis of lignan is relatively limited, compared with those in lignin and flavonoids biosynthesis. Therefore, it is essential to clone and characterize the PAL genes from this valuable medicinal plant. In this study, molecular cloning and characterization of three PAL genes (ScPAL1-3) from S. chinensis was carried out. ScPALs were cloned using RACE PCR. The sequence analysis of the three ScPALs was carried out to give basic characteristics followed by docking analysis. In order to determine their catalytic activity, recombinant protein was obtained by heterologous expression in pCold-TF vector in Escherichia coli (BL21-DE3), followed by Ni-affinity purification. The catalytic product of the purified recombinant proteins was verified using RP-HPLC through comparing with standard compounds. The optimal temperature, pH value and effects of different metal ions were determined. Vmax, Kcat and Km values were determined under the optimal conditions. The expression of three ScPALs in different tissues was also determined. Our work provided essential information for the function of ScPALs.

Adecuación del aporte de proteína natural en el tratamiento de la fenilcetonuria: una revisión bibliográfica / Adequacy of natural protein intake in patients with phenylketonuria: bibliographic review

Introducción: la fenilcetonuria (PKU) es el error congénito del metabolismo de las proteínas más frecuente. El tratamiento dietético consiste en un plan de alimentación con una ingesta de proteínas naturales restringida, un sustituto proteico libre o de bajo contenido en fenilalanina (Phe) y el aporte de alimentos muy bajos en proteínas. El objetivo principal de este trabajo fue investigar si es posible aumentar la ingesta de proteína natural (PN) que se indica a los pacientes con PKU manteniendo los dosajes de Phe en sangre en rangos de seguridad. Materiales y método: se buscaron en 6 bases de datos electrónicas artículos publicados. Se identificaron un total de 154 artículos de Pub Med por intervalo de años desde 1999 a 2020. Se eligieron 15 artículos que se adaptaron a los criterios de inclusión y exclusión y respondían al objeto de estudio de esta revisión bibliográfica. Resultados: hay varios factores que pueden influenciar la estimación de la tolerancia de Phe como la severidad del fenotipo del paciente, la edad, el rango de seguridad de Phe en sangre, la prescripción de Phe y la adherencia al sustituto proteico. Si los niveles de Phe en sangre se mantienen en forma constante dentro del rango adecuado y por un período determinado, se debería considerar un incremento de la ingesta de Phe. El aumento de la ingesta de PN deberá ser realizado de manera controlada, individual y evaluando en forma constante el impacto en los dosajes de Phe en sangre. Conclusión: optimizar la ingesta de PN ofrece una mejora en la calidad de vida de pacientes con PKU, facilita la capacidad del paciente para socializar y contribuye a una mejor adherencia a la dieta(AU).

Introduction: phenylketonuria (PKU) is the most frequent inborn error of protein metabolism. The dietary treatment consists of a diet with a restricted natural protein intake, a free or low phenylalanine (Phe) protein substitute, and the intake of low protein food. The main objective of this work is to analyze if it is possible to increase the natural protein (NP) intake prescribed to PKU patients while maintaining blood Phe dosages within safe range. Materials and method: studies published were searched in 6 electronic data- basis. A total of 154 Pub Med articles were identified by range of years from 1999 to 2020. Fifteen articles which met the inclusion and exclusion criteria and responded to the objective of this bibliographic review were chosen. Results: several factors may influence Phe tolerance, such as severity of the patient´s phenotype, age, blood Phe safe range, Phe prescription and adherence to protein substitute. If Phe blood levels remain constantly within safe range and for a certain period, an increase of Phe intake should be considered. Increase of NP intake must be carried out in a controlled manner, individually and constantly evaluating blood Phe levels. Conclusion: optimizing NP intake offers the PKU patient an improvement in quality of life, facilitates the patient´s ability to socialize and contributes to a better adherence to the diet(AU).

The expression of the recombinant human phenylalanine-tRNA ligase beta subunit gene in hepatocellular carcinoma and its prognostic value / 中华老年医学杂志

Objective:To analyze the expression of the recombinant human phenylalanine-tRNA ligase beta subunit(FARSB)gene in hepatocellular carcinoma(HCC)and explore its association with clinicopathologic characteristics and prognosis.Methods:Data sets of hepatocellular carcinoma and paracancerous tissues were downloaded from the Cancer Genome Atlas(TCGA), and the data were analyzed using the R and Perl programming languages.Cox regression and the Kaplan-Meier method were used to analyze the relationship between clinicopathological characteristics and overall survival.Gene set enrichment analysis(GSEA)was used to predict the signal pathways involved in the regulation of FARSB.qPCR and Western blot were used to verify the expression level of FARSB in hepatocellular carcinoma and adjacent tissues.Results:FARSB was highly expressed in HCC and the prognosis of HCC patients with high FARSB expression was poor.The clinical stage, T stage, M stage and FARSB were significantly correlated with overall survival, while only high FARSB expression was an independent prognostic factor in HCC patients.Conclusions:High expression of FARSB indicates a poor prognosis in HCC patients and FARSB can be used as a marker for poor prognosis in HCC.

Semi-rational design improves the catalytic activity of phenylalanine ammonia lyase from Anabaena variabilis / 药学学报

Phenylalanine ammonia lyase (PAL) can catalyze L-phenylalanine to produce trans-cinnamic acid, which is widely used in the fields of pharmacy, food and agriculture. In particular, phenylalanine ammonia lyase from Anabaena variabilis (AvPAL) is the only protein drug for the treatment of phenylketonuria. However, the poor activity and low stability limit the application in industry of AvPAL. In this study, the key amino acids of substrate-binding cavity in AvPAL were identified by screening the single site saturation mutagenesis library. Subsequently, the impact of replacing M222 with the additional 19 amino acids on activity was also evaluated by site-directed mutagenesis. It was found that the kcat values of mutants M222L and M222V were 90% and 60% higher than that of AvPAL, and the kcat/Km was 1.4 and 1.5 times as that of AvPAL. Molecular docking results revealed that the higher activity of M222L and M222V may be due to the increase of hydrophobicity favorable for the substrate-binding cavity. This study is important for elucidating the structure-function relationship of AvPAL.

Bone Health in Adults with Phenylketonuria: A Cross-Sectional Study

Abstract Available literature documenting BMD in patients with PKU is mostly reported among heterogeneous populations including adults and children. We aim to describe the bone health status among adults (aged >18 years) affected with Phenylketonuria (PKU) and to evaluate the effect of diet and exercise on bone mineral density (BMD). Sample size of the study population was 27. Enrolled patients underwent multi-site Dual-energy X-ray absorptiometry (DXA) scan and laboratory tests. Nutritional and physical activity records were obtained on each subject to ascertain bone health. BMD in patients with PKU was low normal. 14% of the study subjects were found to have osteoporosis in at least one measured skeletal site. 70% had low BMD in one or more of the measured skeletal sites. BMD score was lowest at radius. Moderate correlation was observed between femoral and radial BMD and serum calcium level. Dietary intake of vitamin A was moderately correlated with BMD T-scores in femur. Our results indicate that BMD in patients with PKU is low normal with better BMD with vitamin A intake, trend towards better bone health with physical exercise and Sapropterin intake.

Update on Dietary Compliance, Nutritional Status, and Neuropsychological Functioning in the Chilean Phenylketonuria cohort

Abstract Since 1992, Chile has had a Newborn Screening Program for Phenylketonuria (PKU), which currently has an incidence of 1:18,916 newborns. The objective of the current study was to describe the 2020 follow up of the Chilean PKU cohort. The variables analyzed were: nutritional status, dietary compliance and neuropsychological functioning. We conducted a descriptive cross-sectional statistical analysis. The 271 subjects with PKU had an average age of diagnosis of 17±8 days and a phenylalanine (Phe) level of 1122±546 umol/L. Approximately 80% of protein requirement came from a protein substitute. For those <18 years of age, 80% had good dietary compliance with Phe level between 120-360 umol/L and those >18 years had a median of 522 umol/L (95%CI 468 - 636). Forty-four percent of the active PKU cohort had overweight/obesity. Eighty-five percent of the cohort >4 years of age had a normal intelligence quotient (IQ) (score 80-120). We observed a negative correlation (p <0.001; 95% CI: - 0.5, -0.2) between IQ score and Phe level. The Chilean protocol and protein substitute subsidy for life, together with the follow-up and continuous education carried out by the clinical team has encouraged compliance.

Preliminary screening of therapeutic drugs for phenylalanine hydroxylase deficiency / 中国基层医药

Objective:To screen new drugs for treatment of phenylalanine hydroxylase deficiency.Methods:From October 2019 to October 2020, virtual drug screening was performed in Center of Genetic Medicine, Nanjing Maternity and Child Health Care Hospital, Women's Hospital of Nanjing Medical University computer according to the characteristics of the binding ability of phenylalanine hydroxylase to drug spatial structure. Ten candidate drugs were screened from the FDA drug library (including 2 697 kinds of active pharmaceutical ingredients). A eukaryotic expression system was used to determine the effects of drugs on the activity of phenylalanine hydroxylase at the molecular level. Drug-sensitive mutants were screened.Results:Among the 10 candidate drugs, neoplasm hydrochloride, fluocinonide acetate and risperidone increased 23% [ t = 18.21, P < 0.001, vs. non-drug-treated phenylalanine hydroxylase group (i.e., only solvent and no drug added to the reaction system)], 21% ( t = 3.44, P < 0.05, vs. non-drug-treated phenylalanine hydroxylase group), 31% ( t = 19.57, P < 0.001, vs. non-drug-treated phenylalanine hydroxylase group) of the activity of phenylalanine hydroxylase. The remaining drugs exhibited weak even inhibitory effects on the activity of phenylalanine hydroxylase. 25% of p.D101N mutant could be activated by risperidone ( t = 15.86, P < 0.001, vs. non-drug-treated p.D101N mutant group). Conclusion:Neoplasm hydrochloride, fluocinonide acetate and risperidone can be used as potential therapeutic drugs for phenylalanine hydroxylase deficiency, and p.D101N mutant can be used as the drug-sensitive mutation site.

Transcriptome analysis reveals key enzyme genes involved in lignin biosynthesis pathway in Arctium lappa / 中草药

Objective: To obtain the functional genes in Arctium lappa and analyze the key enzyme genes involved in biosynthesis pathway of lignin. Methods: The transcriptome dataset of roots of A. lappa was obtained by using the BGISEQ-500 sequencing platform. Unigenes were de novo assembled and annotated according to the existing nucleic acids and protein databases. The key enzyme genes involved in lignin biosynthesis pathway were analyzed and the three-dimensional model of phenylalanine ammonialyase (AlPAL) was generated by the SWISS-MODEL and PyMol. Results: A total of 54 215 Unigenes were obtained by de novo assembly, and 42 003 Unigenes were annotated in at least one public database. A total of 1 668 Unigenes were identified to be plant transcription factors (TFs), which belong to 54 TF families, and 423 Unigenes were found to be involved in the biosynthesis pathway of lignin. Structure model indicated that AlPAL was a homotypic tetramer, and each monomer was consisted of three domains, including 4-methyl-imidazole-5-ketone (MIO) domain, core domain and shield domain. The MIO domain contained three conserved amino acids (ASG), which formed the catalytic activity center of the enzyme. Conclusion: This study was the first de novo transcriptome assembly of A. lappa, which will lay the foundation for the identification of functional genes, secondary metabolic pathway and the study of regulation mechanism of biosynthesis pathway of lignin in A. lappa in the future.

Obtención de hidrolizados proteicos bajos en fenilalanina a partir de suero dulce de leche y chachafruto (Erythrina edulis Triana) / Obtaining protein products low in phenylalanine from milk whey and chachafruto (Erythrina edulis Triana)

La fenilcetonuria (PKU) es causada por una actividad deficiente de la enzima fenilalanina hidroxilasa. En los pacientes con esta deficiencia la fenilalanina (Phe) no puede ser convertida en tirosina, aumentando sus niveles en sangre y de otros metabolitos neurotóxicos, provocando un retraso mental irreversible. El tratamiento fundamentalmente se basa en una dieta controlada de Phe. Sin embargo, los alimentos libres o bajos en Phe son escasos. El objetivo de esta investigación es obtener hidrolizados proteicos con bajo contenido de Phe a partir del suero dulce de leche en polvo y harina de E. edulis Triana. El aislado proteico (96,01% proteína cruda) se obtuvo por solubilización y precipitación de las proteínas de la harina, mientras que las proteínas del suero (15,69% proteína cruda) fueron tratadas en su matriz original. Las proteínas del suero y el asilado fueron hidrolizadas enzimáticamente con pepsina y proteasa de Streptomyces griseus. La concentración de Phe se determinó por fluorometría y por HPLC, de lo cual la Phe de las proteínas del suero es liberada una hora antes que las del chachafruto, debido a que las proteínas del suero en parte fueron hidrolizadas en la elaboración del queso. Además, los resultados de la utilización del carbón activados como captor de Phe indican la reducción total del contenido de este aminoácido en los hidrolizados y la reducción de la concentración de otros aminoácidos(AU)

henylketonuria (PKU) is caused by a low activity of the enzyme phenylalanine hydroxylase. In patients with this deficiency, phenylalanine (Phe) cannot be converted to tyrosine, increasing blood levels and other neurotoxic metabolites, causing irreversible mental retardation. The treatment is fundamentally based on a controlled diet of Phe. However, free or low-Phe foods are scarce. The objective of this research is to obtain protein hydrolysates with low Phe content from sweet milk powder and E. edulis Triana flour. The protein isolate (96.01% crude protein) was obtained by solubilization and precipitation of the flour proteins, while the whey proteins (15.69% crude protein) were treated in their original matrix. Serum and asylated proteins were enzymatically hydrolyzed with pepsin and Streptomyces griseus protease. The concentration of Phe was determined by fluorometry and by HPLC, from which the Phe of whey proteins is released one hour earlier than those of chachafruto, due to the fact that the whey proteins were partially hydrolyzed in the elaboration of the cheese. In addition, the results of the use of charcoal activated as Phe captor indicate the total reduction of the content of this amino acid in the hydrolysates and the reduction of the concentration of other amino acids(AU)

Análise da densidade mineral óssea em pacientes com fenilcetonúria e sua correlação com parâmetros nutricionais / Bone mineral density assessment in patients with phenylketonuria and its correlation with nutritional parameters

Introdução: Redução da densidade mineral óssea (DMO) está associada à Fenilcetonúria (PKU), mas a causa desta associação não é completamente entendida. O objetivo desse estudo foi avaliar a ingestão de nutrientes relacionados ao metabolismo ósseo (cálcio, fósforo, magnésio, potássio), e sua associação com a DMO em pacientes com PKU. Métodos: Estudo transversal, observacional. Foram incluídos 15 pacientes (PKU Clássica=8; Leve=7; mediana de idade=16 anos, IQ=15-20), todos em tratamento com dieta restrita em fenilalanina (Phe) e 13 em uso de fórmula metabólica. Foi realizado recordatório alimentar de 24 horas de um dia e demais dados (histórico de fraturas, parâmetros antropométricos, DMO e níveis plasmáticos de Phe, Tyr, cálcio) foram obtidos por revisão de prontuário. Resultados: Nenhum paciente apresentou histórico de fraturas e seis realizavam suplementação de cálcio (alteração prévia da DMO=5; baixa ingestão=1). A mediana dos níveis de Phe foi 11,6 mg/dL (IQ=9,3-13,3). Em relação ao recordatório alimentar, dez indivíduos apresentaram inadequado consumo de carboidratos; 14, de lipídeos; 9, de cálcio; 11, de magnésio; 13, de fósforo; e todos de potássio. A mediana da DMO foi de 0,989 g/cm2 (IQ=0,903-1,069), sendo duas classificadas como reduzidas para idade, ambas de pacientes com PKU Leve que recebiam suplementação de cálcio. Não foi observada correlação entre níveis de Phe, DMO e demais variáveis analisadas. Conclusão: Redução da DMO não foi frequente na amostra, embora ingestão inadequada de cálcio assim o seja. Estudos adicionais são necessários para esclarecer o efeito da Phe e da ingestão dietética sobre o metabolismo ósseo na PKU. (AU)

Introduction: Reduced bone mineral density (BMD) is associated with phenylketonuria (PKU), but this association is not completely understood. This research aimed to evaluate intake of nutrients related to bone metabolism (calcium, phosphorus, magnesium, potassium) and its association with BMD in patients with PKU. Methods: In this cross-sectional, observational study, 15 patients with PKU (Classical=8, Mild=7; median age=16 years, IQ=15-20 years) were included, all of them on phenylalanine (Phe) restricted diet and 13 being supplemented with a metabolic formula. A 24-hour dietary recall was performed and remaining data (history of fractures, anthropometric parameters, BMD and plasma Phe, tyrosine and calcium levels) were obtained through medical chart review. Results: No patient had any fractures and six received calcium supplements, five due to previous change in BMD and one due to inadequate nutritional intake. Median Phe level was 11.6 mg/dL (IQ=9.3-13.3). In relation to dietary recall, all individuals had inadequate intake of some nutrient (carbohydrate=10; lipids=14; calcium=9; magnesium=11; phosphorus=13; potassium=15). The median BMD was 0.989 g/cm2 (IQ=0.903-1.069). Two cases were classified as low BMD for age, both in patients with mild PKU receiving calcium supplements. Conclusion: Reduced BMD was not common in this sample, although inadequate calcium intake was frequently reported. Additional studies are needed to clarify the effect of Phe and dietary intake on bone metabolism in patients with PKU.(AU)

Phenylalanine Hydroxylase (PAH) Genotyping in PKU Argentine Patients

Abstract Phenylketonuria (PKU, OMIM 261600) is predominantly caused by mutations in the PAH gene. One hundred and three Argentine PKU patients were studied by Sanger sequencing; 101 were completely characterized (90.3% were compound heterozygotes). Fifty-four different pathogenic variants were identified. Mutations were distributed all along the PAH gene but concentrated in exon 7 (26%), 12 (12%), 11 (10%), and 6 (10%). 77% were missense, and 77% affected the enzyme catalytic domain, nine mutations accounted for 57% of 179 studied alleles: p.Arg261Gln (Allele frequency(AF):10.6%), c.1066-11G>A (AF:9,5%), p.Arg408Trp (AF:8,3%), p.Tyr414Cys (AF:5,5%), p.Ala403Val, p.Val388Met, and p.Arg158Gln (AF: 5% each), p.Leu48Ser, and p.Ile65Thr (AF:4% each). The predicted phenotype was assigned by Guldberg´s arbitrary value (AV) and compared with the clinical phenotype based in tolerance to Phe intake. 29.1% (n:30) were hyperphenylalaninemias, 18.5% (n:19) mild-PKU, 27.2% (n:28) moderate-PKU and 25.2 % (n:26) classical-PKU. Genotype/phenotype correlation was statistically significant (p<0.001) Overall concordance was 62,5%: 93.3% in hyperphenylalaninemia, 64.7% in mild-PKU and 65.4% in classical patients. The moderate-PKU showed a weak concordance (17%) with milder AV prediction than clinical assessment. 74% of discordant moderate patients harbored p.Arg261Gln, and p.Val388Met. Our cohort is highly heterogeneous, with predominant Mediterranean influence (mainly Spanish), but with differences with other Latin-American countries.

Research progress of synthetic methods of ［18F］F-DOPA / 中国药科大学学报

@#［18F］6-fluoro-3, 4-dihydroxy-L-phenylalanine(［18F］F-DOPA)has been used as a radiotracer for Parkinson′s disease over 30 years. The previously reported electrophilic synthesis method has low radiochemical yield(RCY), low specific activity(SA)and other defects. Recent reported nucleophilic synthesis of ［18F］F-DOPA could overcome the disadvantages. In this paper, the nucleophilic synthetic methods for ［18F］F-DOPA are reviewed.

Characteristics of gene variants among patients with hyperphenylalaninemia from Quanzhou region of Fujian province / 中华医学遗传学杂志

Objective@#To explore the spectrum of genetic variants among patients with hyperphenylalaninemia (HPA) from Quanzhou area of Fujian province.@*Methods@#For 63 children affected with HPA, next generation sequencing was used to identify potential variants in PAH, PTS, PCBD1, QDPR, SPR and GCH1 genes.@*Results@#Fifty two variants underlying phenylalanine hydroxylase deficiency (PAHD) and 13 variants underlying 6-pyruvoyl tetrahydropterin synthase deficiency (PTPSD) were identified. Two patients carried variants of both PAH and PTS genes. The most common variants of the PAH gene were R53H (21.69%), R241C (18.07%), R243Q (12.05%) and EX6-96A>G (7.23%), which were mainly located in exons 7 (32.53%), 2 (21.69%), 6 (9.64%) and 12 (9.64%). The L227M variant of the PAH gene was unreported previously. N52S (35.00%), P87S (25.00%), IVS1-291A>G (10.00%) and T67M (10.00%) variants were the most common variants for the PTS gene and were mainly located in exons 2 (35.00%) and 5 (35.00%).@*Conclusion@#The variant spectrum underlying HPA in Quanzhou area showed a geographical specificity. A novel variant of the PAH gene (L227M) has been detected.

Study of the phenylalanine hydroxylase gene variants in patients with phenylketonuria from Jiangxi province / 中华医学遗传学杂志

Objective@#To delineate the variants spectrum of phenytalanine hydroxylase (PAH) gene among 78 unrelated patients with phenylketonuria (PKU) from Jiangxi province.@*Methods@#The 13 exons and flanking intronic regions of the PAH gene were subjected to PCR amplification and sequencing.@*Results@#A total of 143 variants were detected among the 156 alleles, which included 54 types of variants, which yielded a detection rate of 91.7%. Common variants have included R243Q (26/143, 18.2%), R408Q (10/143, 7.0%), EX6-96A>G (8/143, 5.6%), IVS4-1G>A (7/143, 4.9%), R241C (7/143, 4.9%) and V399V (7/143, 4.9%). In addition, 6 novel variants were detected, which included IVS4-3T>G, Q172H, C284Y, V291L, V329del, and L430R. The variants consisted of missense, splicing, nonsense and deletion variants, which have mainly located in exons 7 (45, 31.5%), 12 (17, 11.9%), 11 (16, 11.2%) and 6 (14, 9.8%).@*Conclusion@#Variants of the PAH gene identified in Jiangxi province mainly involve exons 7, 12, 11 and 6, with the most common variants being R243Q and R408Q. Six novel variants were identified.

Mutation spectrum and new mutation of phenylalanine hydroxylase gene in Guangxi region / 中华实用儿科临床杂志

Objective To investigate the characteristics of the phenylalanine hydroxylase( PAH)gene muta﹣tions in patients With phenylketonuria(PKU)in Guangxi region,in order to provide clinical data for genetic counseling and prenatal gene diagnosis. Methods Thirty－seven children diagnosed as PKU in the Maternal and Children＇s Hos﹣pital of Guangxi Zhuang Autonomous Region Were enrolled in the study betWeen January 2009 and December 2017. Ve﹣nous blood Was collected and the PAH gene sequence Was determined by Sanger sequencing after amplification With the polymerase chain reaction technique. The neW gene mutations Were defined based on the national and international literature revieW and databases. MeanWhile,100 healthy individuals Were selected as the control group for gene sequen﹣cing to confirm Whether the mutation Was a neW one. Results Thirty－seven cases of PKU Were detected for 68 muta﹣tions,With the detection rate being 91. 89%(68／74). Six mutations Were identified in exon 7,Which accounted for 31. 08% of all,exon 12(18. 92%),exon 8(10. 81%)and exon 6(10. 81%)folloWed. A total of 25 different muta﹣tions Were identified Which including 14 missense mutations(56. 00%),7 nonsense mutations(28. 00%),3 splicing junction mutations(12. 00%),and 1 deletion mutation(4. 00%). The most common mutations included c. 1223G＞A (p. R408Q),c. 728G＞A(p. R243Q)and c. 721C＞T( p. R241C),accounting for 14. 86%,13. 51%,and 10. 81%, respectively. After querying international databases,including PAH mutation database and Human Gene Mutation Data﹣base and forecasting softWare,three kinds of mutations c. 314C＞ T(p. T105I),c. 583A＞ G(p. K195E),c . 851G＞A(p. C284Y)Were verified as novel PAH gene mutations. Conclusions The mutation spectrum of the PAH gene in Guangxi has been identified. And 3 kinds of mutations have been identified. This may accumulate valuable information for gene diagnosis and prenatal diagnosis of PKU in Guangxi region.