OBJECTIVES: To investigate the molecular epidemiology of children with phenylketonuria (PKU) in Gansu, China, providing foundational data for intervention strategies. METHODS: A retrospective analysis was conducted on 1 159 PKU families who attended Gansu Provincial Maternity and Child Care Hospital from January 2012 to December 2024. Sanger sequencing, multiplex ligation-dependent probe amplification, whole exome sequencing, and deep intronic variant analysis were used to analyze the PAH gene. RESULTS: For the 1 159 children with PKU, 2 295 variants were identified in 2 318 alleles, resulting in a detection rate of 99.01%. The detection rates were 100% (914/914) in 457 classic PKU families, 99.45% (907/912) in 456 mild PKU families, and 96.34% (474/492) in 246 mild hyperphenylalaninemia families. The 2 295 variants detected comprised 208 distinct mutation types, among which c.728G>A (14.95%, 343/2 295) had the highest frequency, followed by c.611A>G (4.88%, 112/2 295) and c.721C>T (4.79%, 110/2 295). The cumulative frequency of the top 23 hotspot variants reached 70.28% (1 613/2 295), and most variant alleles were detected in exon 7 (29.19%, 670/2 295). CONCLUSIONS Deep intronic variant analysis of the PAH gene can improve the genetic diagnostic rate of PKU. The development of targeted detection kits for PAH hotspot variants may enable precision screening programs and enhance preventive strategies for PKU.
Humans ; Phenylketonurias/epidemiology* ; Female ; Male ; Retrospective Studies ; Phenylalanine Hydroxylase/genetics* ; Mutation ; Child, Preschool ; China/epidemiology* ; Child ; Infant

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.
Child ; Child, Preschool ; Adolescent ; Humans ; Infant, Newborn ; Young Adult ; Adult ; Neonatal Screening ; Follow-Up Studies ; Retrospective Studies ; Phenylketonurias/genetics* ; Phenylalanine Hydroxylase/genetics* ; Phenylalanine/therapeutic use* ; Mutation

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. V_max, K_cat and K_m 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.
Cloning, Molecular ; Escherichia coli/metabolism* ; Phenylalanine/metabolism* ; Phenylalanine Ammonia-Lyase/chemistry* ; Recombinant Proteins ; Schisandra/genetics*

OBJECTIVE: To explore the genetic etiology for an infant featuring convulsive status epilepticus, developmental delay and elevated plasma lactate. METHODS: Whole exome sequencing and mitochondrial D-loop sequencing were carried out for the infant. Candidate variants were verified by Sanger sequencing. Previously reported FARS2 gene variants were searched from the PubMed, Wanfang and CNKI databases. RESULTS: The infant was found to harbor compound heterozygous variants of the FARS2 gene, namely c.925G>A (p.G309S) and c.405C>A (p.H135Q), which were inherited from its mother and father, respectively. The former has been recorded by the HGMD as a pathogenic variant, whilst the latter was predicted to be likely pathogenic based on the guidelines of the American College of Medical Genetics and Genomics. A total of 30 COXPD14 cases were retrieved from the literature, with common mutations including missense variants, in-frame deletions, splice-site variants and large deletions. CONCLUSION The common manifestations of COXPD14 have included developmental delay (96%), status epilepticus (97%) and increased lactic acid (96%). The compound heterozygous variants of the FARS2 gene probably underlay the disorder in this child.
Female ; Humans ; Infant ; Genetic Testing ; Mitochondrial Diseases ; Mitochondrial Proteins/genetics* ; Phenylalanine-tRNA Ligase ; Status Epilepticus ; Exome Sequencing

OBJECTIVE: To explore the serological characteristics and molecular biological mechanism of an a_el subtype specimen. METHODS: The ABO blood typing was identified by routine blood group serological and absorption/elution methods; PCR-SBT method for ABO genotyping: 7 exons of ABO gene were amplified by PCR, the amplified products were purified, and then sequencing primers were designed and the amplified products were sequenced directly for analysis; 3D molecular model was constructed and the difference of free energy (ΔΔG) was used to predict the GTA mutant stability. RESULTS: A antigen was not detected on erythrocytes through absorption and elution tests, which was not consistent with the serological characteristics of a_el, and the serological typing results were ambiguous. The ABO genotype was ABO*AEL.02/O.01.01, and there were two mutations in exon 7 of the gene, c.467C>T and c.646T>A, which could lead to the replacement of proline with leucine at position 156 (p.Pro156Leu) and phenylalanine with isoleucine at position 216 on the GTA, respectively. The 3D model predicts that the mutations do not introduce new hydrogen bonds to the GTA mutant and do not form a new secondary structure, but can lead to an increase in the ΔΔG value of the GTA mutant, suggesting a decrease in protein stability. CONCLUSION The serological characteristics alone is not reliable to determine the a_el subype; the a_el phenotype may be due to the GTA mutant that reduces enzyme stability.
ABO Blood-Group System/genetics* ; Alleles ; Genotype ; Isoleucine/genetics* ; Leucine/genetics* ; Phenotype ; Phenylalanine/genetics* ; Proline/genetics*

Consensus ; Humans ; Nutritional Requirements ; Phenylalanine ; blood ; Phenylalanine Hydroxylase ; deficiency ; Phenylketonurias ; diagnosis ; diet therapy ; genetics ; Practice Guidelines as Topic

OBJECTIVE: To explore the characteristics of PAH gene variants among 113 phenylketonuria patients from Henan Province. METHODS: The 13 exons of the PAH gene were subjected to PCR amplification and direct sequencing. Large fragment deletion and duplication of the PAH gene were detected with a multiple ligation-dependent probe amplification (MLPA) assay. RESULTS: In total 195 point variants and 3 large fragment deletions were detected among the 226 alleles, with the detection rates being 86.28% and 1.33%, respectively. Variants of p.Arg243Gln (18.14%), p.Arg111X (6.19%), p.Arg53His (5.31%), EX6-96A>G (5.31%), p.Tyr356X (4.87%) and p.Val399Val (4.42%) were relatively common. Most of the variants were located in exons 7, 11, 3 and 6. Missense variations were most common. Four novel variations were detected, which included c.1016C>A (p.Ser339Tyr), c.1000T>C (p.Cys334Arg), c.1110G>T (p.Glu370Asp), and IVS6+1G>T. CONCLUSION The PAH gene variations in Henan Province have featured extensive allelic heterogeneity and variety.
China ; Exons ; Humans ; Mutation, Missense ; Phenylalanine Hydroxylase ; genetics ; Phenylketonurias ; genetics ; Point Mutation ; Sequence Deletion

OBJECTIVETo explore the characteristics of (PAH) gene mutations among patients with phenylketonuria (PKU) from Linyi area of Shandong Province.

METHODSFor 51 children affected with PKU and their parents, the 13 exons and their flanking intronic sequences of the PAH gene were directly sequenced with Sanger method.

RESULTSPAH gene mutations were detected in all of the 102 alleles of the patients, which included 31 types of mutations. Common mutations included R243Q (17/102, 16.67%), IVS4-1G to A (9/102, 8.82%), R241C (8/102, 7.84%), R111X (8/102, 7.84%), and V399V (8/102, 7.84%). In addition, two novel mutations, D101N, 345-347del, have been detected. The 31 types of mutations included missense, nonsense, deletion, and splicing mutations, which were mainly located in exons 7 (29, 28.43%), 11 (18, 17.65%), 3 (16, 15.69%) and 12 (13, 12.75%).

CONCLUSIONMutations of the PAH gene in Linyi region mainly distributed in exons 7, 11, and 3, and the most common mutation were R243Q. Two novel mutations, D101N and 345-347del, have been detected.

Base Sequence ; Child ; Child, Preschool ; China ; Exons ; Female ; Humans ; Infant ; Male ; Molecular Sequence Data ; Mutation ; Phenylalanine Hydroxylase ; genetics ; Phenylketonurias ; enzymology ; genetics

Phenylalanine hydroxylase (PAH) is a member of aromatic amino acid hydroxylase (AAAHs) family, and catalyze phenylalanine (Phe) into tyrosine (Tyr). Using immunological and RT-PCR methods to prove the existence of phenylalanine hydroxylase (PAH) gene in the brain of Neanthes japonica in protein and nucleic acid level. Using Western blotting to detect the pah immunogenicity of Neanthes japonica. Making paraffin sections and using immunohistochemical technique to identify the presence and distribution of the phenylalanine hydroxylase gene in the brain of Neanthes japonica. Clone pah gene from the brain of Neanthes japonica by RT-PCR, constructing plasmid and transferring into E. coli to amplification, picking a single homogeneous colony, double digesting then making sequence and comparing homology. Western blotting results showed that the expression of the protein is present in Neanthes japonica brain, immunohistochemistry technique results showed that phenylalanine hydroxylase mainly expressed in abdominal of forebrain, dorsal and sides of midbrain. RT-PCR technique results showed that the phenylalanine hydroxylase exist in the brain of Neanthes japonica and has a high homology with others animals. PAH is present in the lower organisms Neanthes japonica, in protein and nucleic acid level. Which provide the foundation for further study the evolution of aromatic amino acid hydroxylase genes in invertebrate.
Animals ; Blotting, Western ; Brain ; enzymology ; Escherichia coli ; metabolism ; Phenylalanine Hydroxylase ; genetics ; metabolism ; Polychaeta ; enzymology ; genetics

OBJECTIVETo delineate the mutation spectrum of phenylalanine hydroxylase (PAH) gene among patients affected with phenylalanine hydroxylase deficiency (PAHD) in Henan Province of China, and to explore the correlation between the genotype and the phenotype.

METHODSA total of 155 affected children were recruited. Potential mutation of the PAH gene were analyzed by direct sequencing. The genotype-phenotype correlation was analyzed by matching the expected and observed phenotypes.

RESULTSOver 72 mutations and 108 genotypes have been identified. There were 7 homozygous mutations, including 1 case with EX6-96A>G/EX6-96A>G, 1 with R241C/R241C, 1 with R413P/R413P, and 4 with R243Q/R243Q. Among these, 6 patients have presented classic PKU phenotypes, except for a R241C/R241C genotype which has led to mild PKU. In 104 patients carrying compound PAH mutations, 52 were classic, 34 were mild and 39 had mild HPA. Patients who were heterozygous for EX6-96A>G/R241C, R243Q/A434D, EX6-96A>G/R413P and EX6-96A>G/ R241C were found with both the classic PKU and mild PKU phenotypes. Common mutations associated with mild HPA have included R53H, R243Q, V399V and H107R. The common mutations associated with mild PKU included R243Q, R241C, EX6-96A>G, and IVS4-1G>A. The prevalent mutations in classic PKU were R243Q, EX6-96A>G and V399V. The consistency between prediction of the biochemical genotype and observed phenotype was 77.78%, especially in classic PKU, the consistency was up to 82.14%. Significant correlations were disclosed between pretreatment levels of phenylalanine and AV sum (r=-0.6729, P < 0.01).

CONCLUSIONThe mutation spectrum of PAH gene in Henan seems to differ from that of other regions. Independent assortment of mutant alleles may result in a complex genotype-phenotype correlation, but the genotypes of PAHD patients have correlated with the phenotype.

Female ; Genotype ; Humans ; Male ; Mutation ; Phenotype ; Phenylalanine Hydroxylase ; genetics ; Phenylketonurias ; genetics