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Alavanda C, Ceylan Eİ, Kılavuz S, Çıkı K. Comprehensive analyses of phenylalanine hydroxylase variants and phenotypic characteristics of patients in the eastern region of Türkiye. J Pediatr Endocrinol Metab 2024; 37:543-552. [PMID: 38706300 DOI: 10.1515/jpem-2024-0091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/17/2024] [Indexed: 05/07/2024]
Abstract
OBJECTIVES Phenylalanine hydroxylase (PAH) is predominantly a hepatic enzyme that catalyzes phenylalanine (Phe) into tyrosine, which is the rate-limiting step in Phe catabolism. Biallelic variants in the PAH gene cause PAH enzyme deficiency. Phenylketonuria (PKU) is an autosomal recessive disorder that causes neurologic, behavioral, and dermatological findings. PKU could be divided clinically into three types based on the blood Phe levels: classic phenylketonuria (cPKU), mild-moderate phenylketonuria (mPKU), and mild hyperphenylalaninemia (MHP). This study aimed to determine the phenotypic and genotypic characteristics of Turkish PKU patients in the eastern region of Türkiye. METHODS Demographic characteristics, serum Phe levels, treatments, and PAH variants of 163 patients with PKU and hyperphenylalaninemia (HPA) were retrospectively evaluated. Blood Phe levels of the patients were analyzed with the high-performance liquid chromatography method. For PAH gene analysis, next-generation sequencing was performed. RESULTS Of the 163 patients included in the study, 38 (23.3 %) had cPKU, 16 (9.8 %) had mPKU, and 109 (66.9 %) had MHP. Homozygous variants in the PAH gene were detected in 66 (40.5 %) of the patients, while compound heterozygous variants were detected in 97 (59.5 %) patients. Two novel and 35 recurrent variants in the PAH gene were detected. Of the two novel variants, one was missense (p.Phe351Leu) and the other was frameshift (p.Met276Cysfs*65). The most frequently detected variants were p.Thr380Met (18 %), p.Arg261Gln (16.8 %), and p.Ala300Ser (12.8 %). All patients with the homozygous c.1066-11G>A variant exhibited cPKU phenotype. The c.898G>T (p.Ala300Ser), c.1139C>T (p.Thr380Met), and c.1208C>T (p.Ala403Val) variants were statistically related to mild phenotype. On the other hand, c.592_613del (p.Tyr198Serfs*136), c.1028A>G (p.Tyr343Cys), and c.782G>A (p.Arg261Gln) variants were more frequently detected in the cPKU group. CONCLUSIONS Our study, conducted with patients from the eastern region of Türkiye, demonstrates the genetic heterogeneity in the Turkish population. Simultaneously, our research contributes to genotype-phenotype correlation and expands the genotypic spectrum by identifying novel variants.
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Affiliation(s)
- Ceren Alavanda
- Department of Medical Genetics, Van Research and Training Hospital, Van, Türkiye
| | - Emine İpek Ceylan
- Department of Medical Genetics, Van Research and Training Hospital, Van, Türkiye
- Department of Medical Genetics, Dr Abdurrahman Yurtaslan Ankara Oncology Education and Research Hospital, Ankara, Türkiye
| | - Sebile Kılavuz
- Division of Child Nutrition and Metabolism, Department of Pediatrics, School of Medicine, Marmara University, İstanbul, Türkiye
- Division of Child Nutrition and Metabolism, Department of Pediatrics, Van Research and Training Hospital, Van, Türkiye
| | - Kısmet Çıkı
- Division of Child Nutrition and Metabolism, Department of Pediatrics, Van Research and Training Hospital, Van, Türkiye
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Multiplex Snapshot minisequencing for the detection of common PAH gene mutations in Iranian patients with Phenylketonuria. IRANIAN BIOMEDICAL JOURNAL 2023; 27:46-57. [PMID: 36624928 PMCID: PMC9971712 DOI: 10.52547/ibj.3856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Background Phenylketonuria is a common inborn defect of amino acid metabolism in the world. This failure is caused by an autosomal recessive insufficiency of the hepatic enzyme hyperphenylalaninemia (PAH), which catalyzes the irreversible hydroxylation of phenylalanine to tyrosine. More than 1,040 different disease-causing mutations have already been identified in the PAH gene. The most prominent complication of Phenylketonuria, if not diagnosed and treated, is severe mental retardation. Hence, early diagnosis and initiation of nutritional therapy are the most significant measures in preventing this mental disorder. Given these data, we developed a simple and rapid molecular test to detect the most frequent PAH mutations. Methods Multiplex assay was developed based on the SNaPshot minisequencing approach to simultaneously perform genotyping of the 10 mutations at the PAH gene. We optimized detection of these mutations in one multiplex PCR, followed by 10 single-nucleotide extension reactions. DNA sequencing assay was also used to verify genotyping results obtained by SNaPshot minisequencing. Result All 10 genotypes were determined based on the position and the fluorescent color of the peaks in a single electropherogram. Sequencing results of these frequent mutations showed that by using this method, a 100% detection rate could be achieved in the Iranian population. Conclusion SNaPshot minisequencing can be useful as a secondary test in neonatal screening for HPA in neonates with a positive screening test, and it is also suitable for carrier screening. The assay can be easily applied for accurate and time- and cost-efficient genotyping of the selected SNPs in various population.
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Ozturk FN, Akin Duman T. An update of the mutation spectrum of phenylalanine hydroxylase (PAH) gene in the population of Turkey. J Pediatr Endocrinol Metab 2022; 35:663-668. [PMID: 35405047 DOI: 10.1515/jpem-2021-0556] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Accepted: 03/09/2022] [Indexed: 11/15/2022]
Abstract
Phenylketonuria (PKU) is an autosomal recessive disorder of phenylalanine metabolism, mostly caused by PAH gene variants. The aim of this study was to identify the frequency of PAH gene variants in Turkish population with PKU. In 433 patients with PKU, PAH gene was examined using next generation sequencing (NGS) method. IVS10- 11G>A, p.R261Q, p.A300S, p.A403V, and p.T380 variants, which are the most common variants in this study, constituted 45,9% of the variants in our study. Nine novel variants p.A34V, K73Qfs*4, R157H, R261S, p.T266I, p.S310P, T328A, p.F351I, and K363N were identified. This study determines the most common PAH variants in Turkey and shows that PKU can be screened before marriage with the screening kits. Identification of the PAH gene variant spectrum is important for early diagnosis, understanding molecular mechanisms, clinical follow-up, treatment, and genetic counseling. And the novel variants found this study are important for further studies.
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Affiliation(s)
- Fatma Nihal Ozturk
- Department of Medical Genetics, Istanbul Haseki Training and Research Hospital, Istanbul, Turkey
| | - Tugba Akin Duman
- Department of Medical Genetics, Istanbul Haseki Training and Research Hospital, Istanbul, Turkey
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Moradi K, Alibakhshi R, Shafieenia S, Azimi A. Problem of borderline hemoglobin A2 levels in an Iranian population with a high prevalence of α- and β-thalassemia carriers. EGYPTIAN JOURNAL OF MEDICAL HUMAN GENETICS 2022. [DOI: 10.1186/s43042-022-00279-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
It is difficult to classify a small fraction of α- and β-thalassemia (α- and β-thal) carriers based on their Hb A2 levels. Here, we report the results of a molecular investigation in a cohort of thalassemia carriers with borderline Hb A2 levels originated from western Iran.
Results
The documents of 5956 α- or β-thal carriers were reviewed. The frequency of individuals with borderline Hb A2 levels in this cohort was 436 (7.32%). A total of 12 different α-thal and 27 different β-thal variants were identified in this study.
Conclusions
Our data showed that individuals with borderline Hb A2 are not uncommon in our population. Moreover, preselection of α- and β-thal carriers with borderline Hb A2 levels based on Hb A2, mean corpuscular volume (MCV), and mean cell hemoglobin (MCH) is not advisable in our population. Therefore, it is necessary to investigate both α- and β-globin genes in cases with borderline Hb A2 levels, especially if the partner is a carrier of β-thal or α0-thal.
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Zeinab Khazaei Koohpar, Qasemiyan Y, Ardakani HH, Hashemi M, Kimiajou M, Mohammadian S, Zaeri H. Mutation Spectrum of the Phenylalanine Hydroxylase Gene in Phenylketonuria Patients in Golestan Province, Iran. BIOL BULL+ 2021. [DOI: 10.1134/s1062359020060084] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Alibakhshi R, Moradi K, Ghadiri K. The status of PAH gene-VNTR alleles and mini-haplotypes associations with PAH gene mutations in Iranian Kurdish PKU patients. Med J Islam Repub Iran 2019; 33:88. [PMID: 31696082 PMCID: PMC6825400 DOI: 10.34171/mjiri.33.88] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Indexed: 11/17/2022] Open
Abstract
Background: The analysis of haplotypes/mini-haplotypes in the PAH gene has been used as an informative tool in several genetic anthropology studies. Considering the notion that Iranian population is one of the most heterogeneous i the world, this study was conducted to evaluate the association of VNTR-STR mini-haplotypes with the PAH gene mutations in PKU patients in Kermanshah province. Methods: A total of 24 unrelated Kurdish PKU patients with the known PAH gene causing mutations and 72 healthy controls were selected. The DNA fragments containing VNTR and STR systems were amplified by polymerase chain reaction (PCR). For VNTR system, PCR products were separated using electrophoresis on 2.5% agarose gel. For STR system, the samples were analyzed using DNA sequencing analysis version 5.2 software. Results: Overall, 5 PAH-VNTR-alleles, including VNTR3, 7, 8, 9, 12, and 3 PAH-STR-alleles, including STR238, 242, and 250, were detected in this study. VNTR3 and 8 alleles had the most frequency among healthy controls. Also, 6 different mini-haplotype alleles were found to be associated with PKU chromosomes. The 2 most prevalent mutations in Kermanshah province, IVS2+5G>C and IVS9+5G>A, were strongly linked to mini-haplotypes 9/242 and 8/238, respectively. Conclusion: The distributions and frequencies of VNTR alleles in Kurdish population have the most similarity to alleles previously described in European Caucasian families. Moreover, since the most common mutations in Kermanshah PKU chromosomes are rare and this was the first study on mini-haplotypes VNTR/STR among Iranian Kurdish PKU patients, given that this study was the first of its kind, it was not possible to compare its results with that of other studies on Iranian and non-Iranian populations.
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Affiliation(s)
- Reza Alibakhshi
- Department of Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Keivan Moradi
- Medical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Keyghobad Ghadiri
- Infectious Disease Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
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Genotypes of 2579 patients with phenylketonuria reveal a high rate of BH4 non-responders in Russia. PLoS One 2019; 14:e0211048. [PMID: 30668579 PMCID: PMC6342299 DOI: 10.1371/journal.pone.0211048] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 12/30/2018] [Indexed: 12/12/2022] Open
Abstract
Phenylalanine hydroxylase (PAH) deficiency is responsible for most cases of phenylketonuria (PKU). Furthermore, numerous studies on BH4-sensitive PAH deficiency have been conducted. To date, BH4, a cofactor of PAH, has not been used to treat PKU in Russia.Genotype data of patients with PKU can be used to predict their sensitivity to BH4 therapy. A cohort of 2579 patients with PKU from Russia was analyzed for 25 common PAH gene mutations using custom allele-specific multiplex ligation-dependent probe amplification-based technology. A mutation detection rate of 84.1% chromosomes was accomplished. Both pathogenic alleles were identified in 73.1% of patients. The most frequent pathogenic variants were p.Arg408Trp (50.9%), p.Arg261Gln (5.3%), p.Pro281Leu (3.5%), IVS12+1G>A (3.1%), IVS10-11G>A (2.6%), and p.Arg158Leu (2.4%). The exact boundaries of a PAH exon 5 deletion were defined as EX5del4154ins268 (c.442-2913_509+1173del4154ins268). Severe phenotypes prevailed in the cohort, and classical PKU was observed in 71.8% cases. Due to the genotype-based prediction, 55.9% of the probands were non-responders to the BH4-treatment, and 20.2% were potential responders. Analysis of genotype data is useful to predict BH4 response in PKU patients. The high rate of non-responders among Russian patients was due to the high allele frequency of severe PAH mutations.
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Zinchenko RA, Makaov AK, Kadyshev VV, Galkina VA, Dadali EL, Shurygina MF, El’chinova GI, Mikhailova LK, Marakhonov AV, Vasilyeva TA, Petrova NV, Gundorova P, Tanas AS, Strelnikov VV, Polyakov AV, Ginter EK. Medical Genetic Study of Hereditary Diseases in Abazins of the Karachay-Cherkess Republic. RUSS J GENET+ 2018. [DOI: 10.1134/s1022795418060170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Zamanfar D, Jalali H, Mahdavi MR, Maadanisani M, Zaeri H, Asadpoor E. Investigation of Five Common Mutations on Phenylalanine Hydroxylase Gene of Phenylketonuria Patients from Two Provinces in North of Iran. Int J Prev Med 2017; 8:89. [PMID: 29184640 PMCID: PMC5686925 DOI: 10.4103/ijpvm.ijpvm_378_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 09/09/2017] [Indexed: 11/06/2022] Open
Abstract
Background: There are more than 500 different mutations on phenylalanine hydroxylase (PAH) gene that is responsible for phenylketonuria (PKU) diseases and the spectrum of these mutations is varied in different populations. The main clinical manifestation of untreated patients is severe mental retardation. The PAH gene, that is 90 kb long, is consisted of 13 exons and 12 introns. The aim of the present study was to identify the frequency of five common mutations on PAH gene among patients with PKU in Mazandaran and Golestan provinces including c.1066-11G>A, p. R261Q, p. R252W, p. R261X, and c.1200 + 1G>C. Methods: Forty unrelated PKU patients, that 22 of them, were from Mazandaran and 18 of them from Golestan provinces were enrolled in the study. Genomic DNA was extracted from leukocytes using Qiagen DNA extraction kit and polymerase chain reaction - restriction fragment length polymorphism method was applied to detect five common mutations. Results: Three out of the 5 investigate mutations were identified among the patients. The c.1066-11G>A mutation has the highest frequency (27.5%) among the patients and the frequency of p. R261Q and p. R261X mutations were 3.75 and 1.25%, respectively. In Golestan province, only c.1066-11G>A mutation was observed in investigated alleles. Conclusions: The high frequency of c.1066-11G>A mutation in Golestan province may be related to genetic drift, founder effect, and consanguinity.
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Affiliation(s)
- Daniel Zamanfar
- Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hossein Jalali
- Students research committee, Thalassemia Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Reza Mahdavi
- Students research committee, Thalassemia Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Morteza Maadanisani
- Diabetes Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hossein Zaeri
- Neonatal and Children Health Research Center, Geolstan University of Medical Sciences, Gorgan, Iran
| | - Eynollah Asadpoor
- Central Health Center, Mazandaran University of Medical Sciences, Sari, Iran
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Gundorova P, Zinchenko RA, Makaov AK, Polyakov AV. The spectrum of mutations in the PAH gene in patients with hyperphenylalaninemia from the Karachay-Cherkess Republic. RUSS J GENET+ 2017. [DOI: 10.1134/s1022795417070043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Molecular analysis of exon 13 of cystic fibrosis patients in Middle East: High frequency of K710X mutation. Meta Gene 2017. [DOI: 10.1016/j.mgene.2016.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Gundorova P, Stepanova AA, Makaov AK, Zinchenko RA, Abaykhanova ZM, Polyakov AV. Mutation spectrum of the PAH gene in phenylketonuria patients in the Karachay-Cherkess Republic (Russia). RUSS J GENET+ 2016. [DOI: 10.1134/s1022795416110041] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Goldar P, Givianrad MH, Shams A. Effect of ultrafiltered milk permeate and non-dairy creamer powder concentration on low phenylalanine yoghurt's physicochemical properties during storage. Journal of Food Science and Technology 2016; 53:3053-3059. [PMID: 27765976 DOI: 10.1007/s13197-016-2278-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 05/21/2016] [Accepted: 06/07/2016] [Indexed: 10/21/2022]
Abstract
Phenylketonuria (PKU) is a genetic disorder that has no cure and all patients with this disorder must adhere to a special diet to prevent the onset of symptoms and mental retardation in children. In this study, analog yoghurt with good and acceptable nutrition benefit for PKU patients was produced. Accordingly, ultrafiltered milk permeate was added at two different concentrations of 4 and 5 w/w % and non-dairy creamer at two different concentrations of 1.5 and 2 w/w %. Subsequently, pH, acidity, protein, fat, dry matter, humidity, syneresis and Phe of the yogurts were determined. Protein content, dry matter, pH, acidity and Phe in the analog yogurt with 5 % permeate and 2 % non-dairy creamer were higher than other yoghurt samples, significantly (P < 0.05). During the storage, pH and syneresis of samples reduced, while acidity significantly increased. Phe content of analog yoghurt was low (274 mg/kg).
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Affiliation(s)
- Parisa Goldar
- Department of Food Science and Technology, Pharmaceutical Science Branch, Islamic Azad University, Tehran, Iran
| | - Mohammad Hadi Givianrad
- Department of Marine Chemistry, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Akbar Shams
- Department of Food Science and Technology, Pharmaceutical Science Branch, Islamic Azad University, Tehran, Iran
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Alibakhshi R, Moradi K, Mohebbi Z, Ghadiri K. Mutation analysis of PAH gene in patients with PKU in western Iran and its association with polymorphisms: identification of four novel mutations. Metab Brain Dis 2014; 29:131-8. [PMID: 24048906 DOI: 10.1007/s11011-013-9432-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Accepted: 08/21/2013] [Indexed: 10/26/2022]
Abstract
Phenylketonuria (PKU) is an autosomal recessive disorder characterized by a mutation in the phenylalanine hydroxylase (PAH) gene. Untreated PKU can lead to mental retardation, seizures, and other serious medical problems. This study was designed to investigate the status of molecular defects in the PAH gene and their association with polymorphisms in Kurdish patients with PKU in the Kermanshah province, western Iran. The study was conducted on 27 unrelated patients with PKU over a 2-year period (from 2010 to 2012). All 13 exons plus exon-intron boundaries of the PAH gene were analyzed and we identified 15 different mutations, including two novel mutations, in 51 of the 54 mutant alleles (diagnostic efficiency of 94.4 %). IVS4 + 1G > C (c.441 + 1G > C) and IVS7 - 5 T > C (c.843 - 5 T > C) are novel mutations that have not been reported in the academic literature or the PAH locus database ( http://www.pahdb.mcgill.ca ); therefore, they may be specific to the Kurdish population. IVS2 + 5G > C and IVS9 + 5G > A were the two most prevalent mutations in our sample, with frequencies of 26 % and 17 %, respectively. The second most common mutations were p.R261X, IVS10 - 11G > A, p.K363 > Nfs and IVS7 - 5 T > C, with each showing a relative frequency of 7.4 %. All other detected mutations, including p.F55 > Lfs, p.R176X, p.R243Q, p.V230I, p.R243X, p.R261Q, IVS8 - 7A > G and p.E390G had frequencies of less than 4 %. The present study showed that there is a distinct difference in the characteristics of PAH mutations between the Kermanshah province and other parts of Iran, suggesting that Kermanshah may have a unique population distribution of PAH gene mutations. Iran lies on the route of major ancient movements of the Caucasian people toward the Mediterranean basin, and Kermanshah has previously been called the gateway to Asia. Most of the mutations identified in this study are common in the Mediterranean region. Therefore, our findings are consistent with the historical and geographical links between the Iranian population and the populations of Mediterranean region.
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Affiliation(s)
- Reza Alibakhshi
- Department of Biochemistry, School of Medicine, Kermanshah University of Medical Sciences, Kermanshah, Iran,
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Moradi K, Alibakhshi R, Khatami S. The proportion of tetrahydrobiopterin deficiency and PAH gene deficiency variants among cases with hyperphenyalaninemia in Western Iran. INDIAN JOURNAL OF HUMAN GENETICS 2014; 19:454-8. [PMID: 24497712 PMCID: PMC3897142 DOI: 10.4103/0971-6866.124375] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Defects either in phenylalanine hydroxylase (PheOH) or in the production and recycling of its cofactor (tetrahydrobiopterin [BH4]) are the causes of primary hyperphenylalaninemia (HPA). The aim of our study was to investigate the current status of different variants of HPA Kurdish patients in Kermanshah province, Iran. MATERIALS AND METHODS From 33 cases enrolled in our study, 32 were identified as HPA patients. Reassessing of pre-treatment phenylalanine concentrations and the analysis of urinary pterins was done by high-performance liquid chromatography method. RESULTS A total of 30 patients showed PAH deficiency and two patients were diagnosed with BH4 deficiency (BH4/HPA ratio = 6.25%). Both of these two BH4-deficient patients were assigned to severe variant of dihydropteridine reductase (DHPR) deficiency. More than 75% of patients with PAH deficiency classified as classic phenylketonuria (PKU) according their levels of pre-treatment phenylalanine concentrations. CONCLUSION Based on the performed study, we think that the frequency of milder forms of PKU is higher than those was estimated before and/or our findings here. Furthermore, the frequency of DHPR deficiency seems to be relatively high in our province. Since the clinical symptoms of DHPR deficiency are confusingly similar to that of classic PKU and its prognosis are much worse than classical PKU and cannot be solely treated with the PKU regime, our pilot study support that it is crucial to set up screening for BH4 deficiency, along with PAH deficiency, among all HPA patients diagnosed with HPA.
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Affiliation(s)
- Keyvan Moradi
- Department of Genetics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Reza Alibakhshi
- Department of Biochemistry, School of Medicine, Kermanshah, Iran ; Nano Drug Delivery Research Centre, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Shohreh Khatami
- Department of Biochemistry, Pasteur Institute of Iran, Tehran, Iran
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