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Alghamdi MA, O'Donnell‐Luria A, Almontashiri NA, AlAali WY, Ali HH, Levy HL. Classical phenylketonuria presenting as maternal PKU syndrome in the offspring of an intellectually normal woman. JIMD Rep 2023; 64:312-316. [PMID: 37701331 PMCID: PMC10494492 DOI: 10.1002/jmd2.12384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 07/06/2023] [Accepted: 07/11/2023] [Indexed: 09/14/2023] Open
Abstract
Phenylketonuria (PKU) is an autosomal recessive inborn error of metabolism resulting from a deficiency of phenylalanine hydroxylase (PAH). If untreated by dietary restriction of phenylalanine intake, impaired postnatal cognitive development results from the neurotoxic effects of excessive phenylalanine (Phe). Signs and symptoms include severe intellectual disability and behavior problems with a high frequency of seizures and variable microcephaly. Maternal PKU syndrome refers to fetal damage resulting in congenital abnormalities when the mother has untreated PKU during pregnancy. Here, we report an intellectually normal 32-year-old female who presented with recurrent pregnancy loss and two neonatal deaths with congenital heart disease, microcephaly, intrauterine growth restriction, and respiratory distress. She was diagnosed with PKU through exome sequencing performed for carrier testing with a homozygous pathogenic variant in the PAH gene, c.169_171del, p.(Glu57del) that is associated with classical PKU. Consistent with the genetic finding, she had a markedly increased plasma phenylalanine concentration of 1642 μmol/L (normal <100). This case demonstrates that recurrent pregnancy loss due to untreated maternal PKU may present as an initial finding in otherwise unsuspected classical PKU and illustrates that extreme degrees of variable expressivity may occur in classical PKU. Moreover, this case illustrates the value of genomic sequencing of women who experience recurrent pregnancy loss or neonatal anomalies.
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Affiliation(s)
- Malak Ali Alghamdi
- Harvard Medical SchoolBostonMassachusettsUSA
- Medical Genetic Division, Pediatric DepartmentCollege of Medicine, King Saud UniversityRiyadhSaudi Arabia
- Program in Medical and Population GeneticsBroad Institute of MIT and HarvardCambridgeMassachusettsUSA
| | - Anne O'Donnell‐Luria
- Harvard Medical SchoolBostonMassachusettsUSA
- Program in Medical and Population GeneticsBroad Institute of MIT and HarvardCambridgeMassachusettsUSA
- Division of Genetics and GenomicsBoston Children's HospitalBostonMassachusettsUSA
| | - Naif A. Almontashiri
- Center for Genetics and Inherited Diseases (CGID)Taibah UniversityMadinahSaudi Arabia
| | - Wajeih Y. AlAali
- Dr. Sulaiman Al Habib Medical GroupArryan HospitalRiyadhSaudi Arabia
| | - Hebatallah H. Ali
- Research Center, College of MedicineKing Saud UniversityRiyadhSaudi Arabia
| | - Harvey L. Levy
- Harvard Medical SchoolBostonMassachusettsUSA
- Program in Medical and Population GeneticsBroad Institute of MIT and HarvardCambridgeMassachusettsUSA
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Qiu X, Zhao P, Luo J, Li G, Deng L, Zeng Y, Xu L, Zhou J. Biochemical and molecular features of tetrahydrobiopterin deficiency in Fujian Province, southeastern China. Front Genet 2023; 14:1250568. [PMID: 37636258 PMCID: PMC10451069 DOI: 10.3389/fgene.2023.1250568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 08/04/2023] [Indexed: 08/29/2023] Open
Abstract
The estimated prevalence of tetrahydrobiopterin deficiency (BH4D) and the mutational spectrum of the causal 6-pyruvoyl-tetrahydropterin synthase (PTS) gene vary widely according to race and region. This study assessed the prevalence and genetic characteristics of BH4D in Fujian Province, southeastern China. A total of 3,204,067 newborns were screened between 2012 and 2022 based on the phenylalanine level and the phenylalanine/tyrosine ratio in dried blood spots. Differential diagnosis was determined by the urine purine spectrum, dihydropteridine reductase activity in red blood cells, and genetic testing. The PTS mutation spectrum and genotypes were determined by next-generation sequencing. A total of 189 newborns were diagnosed with hyperphenylalaninemia (HPA) over the study period, including 159 with phenylalanine hydroxylase deficiency and 30 with BH4D. Therefore, the prevalence of BH4D in Fujian was 9.36 per 1,000,000 live births (30/3,204,067) and the proportion of BH4D among patients with HPA was 15.87% (30/189). A total of 58 PTS alleles were identified in the 29 patients with PTS deficiency (PTPSD), and those alleles were composed of 10 different variants, including eight missense variants and two splice-site variants. The most prevalent variants were c.155A>G, p.Asn52Ser (44.83%); c.259C>T, p.Pro87Ser (39.66%); and c.84-291A>G, p.Tyr27Argfs*8 (3.45%). The predominant genotype was c [155A>G]; [259C>T] (11/29, 37.93%). The prevalence of BH4D and the spectrum of associated PTS mutations were successfully determined for the first time in Fujian Province, southeastern China. Since the mutation spectrum of PTS is region-specific, such data will facilitate molecular diagnosis and genetic counseling in PTPSD cases.
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Affiliation(s)
- Xiaolong Qiu
- Genetic Diagnosis and Therapy Center, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Peiran Zhao
- Genetic Diagnosis and Therapy Center, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Jinying Luo
- Obstetrics and Gynecology Department, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Guilin Li
- Department of Preventive Medicine, School of Public Health, Fujian Medical University, Fuzhou, China
| | - Lin Deng
- Obstetrics and Gynecology Department, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Yinglin Zeng
- Genetic Diagnosis and Therapy Center, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Liangpu Xu
- Genetic Diagnosis and Therapy Center, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
| | - Jinfu Zhou
- Genetic Diagnosis and Therapy Center, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Maternity and Child Hospital, College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Medical University, Fuzhou, China
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Sur LM, Mager MA, Bolunduţ AC, Trifa AP, Anton-Păduraru DT. Two Cases of 6-Pyruvoyl Tetrahydropterin Synthase Deficiency: Case Report and Literature Review. CHILDREN (BASEL, SWITZERLAND) 2023; 10:children10040727. [PMID: 37189976 DOI: 10.3390/children10040727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 03/26/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023]
Abstract
6-pyruvoyl tetrahydropterin synthase deficiency (PTPSD) is a rare neurometabolic disease that can be diagnosed in newborn screening (NBS) and is part of the family of tetrahydrobiopterin deficiency disorders (BH4Ds). It is essential to diagnose and treat this disease early to prevent permanent neurological damage secondary to this neurotransmitter disorder. We present the first two cases of PTPSD in Romania that were genetically confirmed and treated late. Improving the diagnosis and monitoring procedures in Romania with correct metabolic management will prevent severe neurological impairment from PTPSD or other BH4Ds.
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Affiliation(s)
- Lucia Maria Sur
- Faculty of General Medicine, University of Medicine and Pharmacy Iuliu Haţieganu Cluj-Napoca, 400015 Cluj-Napoca, Romania
- Children's Emergency Hospital, Motilor Street No 68, 400015 Cluj-Napoca, Romania
| | - Monica Alina Mager
- Faculty of General Medicine, University of Medicine and Pharmacy Iuliu Haţieganu Cluj-Napoca, 400015 Cluj-Napoca, Romania
- Children's Emergency Hospital, Motilor Street No 68, 400015 Cluj-Napoca, Romania
| | - Alexandru-Cristian Bolunduţ
- Faculty of General Medicine, University of Medicine and Pharmacy Iuliu Haţieganu Cluj-Napoca, 400015 Cluj-Napoca, Romania
- Children's Emergency Hospital, Motilor Street No 68, 400015 Cluj-Napoca, Romania
| | - Adrian-Pavel Trifa
- Faculty of Medicine, Medical Genetics, University of Medicine and Pharmacy Victor Babes Timisoara, 400349 Cluj-Napoca, Romania
| | - Dana Teodora Anton-Păduraru
- Faculty of Medicine, Mother and Child Discipline, Department of Pediatrics, University of Medicine and Pharmacy Grigore T. Popa Iasi, 700115 Iasi, Romania
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Xie K, Zeng B, Zhang L, Chen S, Zou Y, Yuan H, Huang S, Wang F, Lu Q, Liu Y, Yang B. Mutation spectrum of PTS gene in patients with tetrahydrobiopterin deficiency from jiangxi province. Front Genet 2022; 13:1077729. [PMID: 36583021 PMCID: PMC9792861 DOI: 10.3389/fgene.2022.1077729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 11/29/2022] [Indexed: 12/15/2022] Open
Abstract
Background: Hyperphenylalaninemia (HPA) is the most common inborn error in amino acid metabolism. It can be primarily classified into phenylalanine hydroxylase (PAH) deficiency and tetrahydrobiopterin (BH4) deficiency. BH4 deficiency (BH4D) is caused by genetic defects in enzymes involved in the biosynthesis and regeneration of BH4. 6-pyruvoyl-tetrahydropterin synthase (PTPS/PTS), which is encoded by the PTS gene, participates in the biosynthesis of BH4. PTPS deficiency (PTPSD) is the major cause of BH4D. In this study, we investigated that the prevalence of BH4D in Jiangxi province was approximately 12.5 per 1,000,000 live births (69/5,541,627). Furthermore, the frequency of BH4D was estimated to be 28.8% (69/240) in the HPA population of Jiangxi. In this study, we aimed to characterize the mutational spectrum of the PTS gene in patients with PTPSD from Jiangxi province. Method: Newborn screening data of Jiangxi province from 1997 to 2021 were analyzed and 53 families with PTPSD were enrolled for the analysis of the PTS gene variants by Sanger sequencing. Results: 106 variants were identified in 106 alleles of 53 patients with PTPSD, including 13 types of variants reported previously, and two novel variants (c.164-36A>G and c.146_147insTG). The predominant variant was c.259C>T (47.2%), followed by c.84-291A>G (19.8%), c.155A>G (8.5%), c.286G>A (6.6%) and c.379C>T (4.7%). Conclusion: The results of this study can not only provide guidance for the molecular diagnosis and genetic counseling in cases of PTPS deficiency but also enrich the PTS mutation database.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Qing Lu
- *Correspondence: Qing Lu, ; Yanqiu Liu, ; Bicheng Yang,
| | - Yanqiu Liu
- *Correspondence: Qing Lu, ; Yanqiu Liu, ; Bicheng Yang,
| | - Bicheng Yang
- *Correspondence: Qing Lu, ; Yanqiu Liu, ; Bicheng Yang,
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Vela-Amieva M, Alcántara-Ortigoza MA, Ibarra-González I, González-del Angel A, Fernández-Hernández L, Guillén-López S, López-Mejía L, Carrillo-Nieto RI, Fiesco-Roa MO, Fernández-Lainez C. Genotypic spectrum underlying tetrahydrobiopterin metabolism defects: Experience in a single Mexican reference center. Front Genet 2022; 13:993612. [PMID: 36313470 PMCID: PMC9597361 DOI: 10.3389/fgene.2022.993612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/30/2022] [Indexed: 11/29/2022] Open
Abstract
Background: Pterin profiles or molecular analyses of hyperphenylalaninemia (HPA) caused by phenylalanine hydroxylase (PAH) deficiency or tetrahydrobiopterin deficiency (BH4D) are not always available in low- or middle-income countries, including Mexico, limiting information regarding the phenotypic and genotypic characteristics of patients exhibiting BH4D. Objective: To report the genotypes underlying BH4D and the clinical presentation in unrelated Mexican HPA pediatric patients with normal PAH genotypes who attended a single metabolic reference center in Mexico. Methods: Automated Sanger sequencing of the PTS, QDPR, and PCBD1 genes of 14 HPA patients was performed. Predicted effects on protein structure caused by missense variants were assessed by in silico protein modeling. Results and discussion: A high prevalence of BH4D was noted in our HPA cohort (9.8%, N = 14/142). Clinically relevant biallelic genotypes were identified in the PTS (N = 7/14 patients), QDPR (N = 6/14 patients), and PCBD1 (N = 1/14 patients) genes. Four novel QDPR variants [c.714dup or p.(Leu239Thrfs*44), c.106-1G>T or p.(?), c.214G>T or p.(Gly72*), and c.187_189dup or p.(Gln63dup)] were identified. In silico protein modeling of six missense variants of PTS [p.(Thr67Met), p.(Glu81Ala), and p.(Tyr113Cys)], QDPR [p.(Cys161Phe) and p.(Pro172Leu)], and PCBD1 [p.(Glu97Lys)] supports their pathogenicity. Progressive neurological symptoms (mainly intellectual and motor impairment and even death in three patients) were noted in all patients with biallelic QDPR genotypes and in 5/7 patients bearing biallelic PTS genotypes. The single homozygous PCBD1 p.(Glu97Lys) patient remains asymptomatic. Conclusion: A higher proportion of BH4D (9.8 vs. 1%–2% worldwide), attributable to a heterogeneous mutational spectrum and wide clinical presentation, was noted in our Mexican HPA cohort, with the PTS-related HPA disorder being the most frequent. Sequencing-based assays could be a reliable approach for diagnosing BH4D in our population.
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Affiliation(s)
- M. Vela-Amieva
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - M. A. Alcántara-Ortigoza
- Laboratorio de Biología Molecular, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - I. Ibarra-González
- Unidad de Genética de la Nutrición, Instituto de Investigaciones Biomédicas, UNAM, Ciudad de México, México
| | - A. González-del Angel
- Laboratorio de Biología Molecular, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - L. Fernández-Hernández
- Laboratorio de Biología Molecular, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - S. Guillén-López
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - L. López-Mejía
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - R. I. Carrillo-Nieto
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
| | - M. O. Fiesco-Roa
- Laboratorio de Citogenética, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
- Maestría y Doctorado en Ciencias Médicas y de la Salud, UNAM, Ciudad de México, México
| | - C. Fernández-Lainez
- Laboratorio de Errores Innatos del Metabolismo y Tamiz, Instituto Nacional de Pediatría, Secretaría de Salud, Ciudad de México, México
- *Correspondence: C. Fernández-Lainez,
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Çınar M, Kılıç Yıldırım G, Kocagil S, Çilingir O. Spectrum of PAH gene mutations and genotype-phenotype correlation in patients with phenylalanine hydroxylase deficiency from Turkey. J Pediatr Endocrinol Metab 2022; 35:639-647. [PMID: 35355500 DOI: 10.1515/jpem-2022-0047] [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: 01/27/2022] [Accepted: 03/07/2022] [Indexed: 11/15/2022]
Abstract
OBJECTIVES The aim of our study was to define the genotype-phenotype correlations of mutations in the PAH gene among the Turkey's Central Anatolian region. METHODS Demographic characteristics of 108 patients with hyperphenylalaninemia (HPA) and 94 patients whose diagnosis was confirmed by PAH gene analysis (Sanger DNA Sequence Analysis and Next-Generation Sequencing) were determined retrospectively. Blood phenylalanine levels were analyzed using the high-performance liquid chromatography method. RESULTS Mild HPA-not-requiring-treatment (NT) was found in 50.9% of the patients, and a classical phenylketonuria (PKU) phenotype was found in 25.9%. Forty-seven types of variants were identified. The predominant variants were p.Ala403Val (9.9%), p.Ala300Ser (9.4%), and c.1066-11G>A (splicing) (9.4%). Missense mutations accounted for 68% of mutations and attenuated the clinical impact; splice variations were found in 14.8% of cases with severe features. The p.Thr380Met allele was specific to the mild HPA-NT group. The c.1066-11G>A (splicing) allele was associated with classical PKU, whereas the p.Arg408Trp allele was linked to severe symptoms. Three variations of unknown clinical significance were discovered: c.706+4A>T (splicing), c.843-5T>C (splicing), and p.Thr323=. Of these variants, the patient who was homozygous for the c.843-5T>C (splicing) allele related to the classical PKU phenotype. 70% of the patients who underwent tetrahydrobiopterin (BH4) test were responsive. Phenotypes that responded to BH4 treatment were mostly mild phenotypes. CONCLUSIONS The PAH genotype is the main factor that determines the phenotype of PKU. Establishing the relationship between the identified genetic mutations and phenotypic characteristics will provide very important data for each patient in terms of the specific management style.
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Affiliation(s)
- Müge Çınar
- Pediatrics, Bozüyük State Hospital, Bilecik, Turkey
| | - Gonca Kılıç Yıldırım
- Department of Paediatrics, Eskisehir Osmangazi University Faculty of Medicine, Division of Child Nutrition and Metabolism, Eskisehir, Turkey
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
| | - Sinem Kocagil
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
- Department of Genetics and Genomics Medicine, Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
| | - Oğuz Çilingir
- Eskisehir Osmangazi University Faculty of Medicine, Meselik Campuse, Odunpazari, Turkey
- Department of Genetics and Genomics Medicine, Eskisehir Osmangazi University Faculty of Medicine, Eskisehir, Turkey
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Epidemiology of Phenylketonuria Disease in Jordan: Medical and Nutritional Challenges. CHILDREN (BASEL, SWITZERLAND) 2022; 9:children9030402. [PMID: 35327772 PMCID: PMC8947754 DOI: 10.3390/children9030402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/05/2022] [Revised: 03/05/2022] [Accepted: 03/10/2022] [Indexed: 02/08/2023]
Abstract
Background: Phenylketonuria (PKU) is the most frequent inborn error in amino acid metabolism caused by a deficiency of the phenylalanine hydroxylase enzyme (PAH). If PKU is left untreated, high concentrations of phenylalanine (Phe) accumulate in the blood, leading to severe brain dysfunction, neurodevelopmental, behavioral and psychological problems. Data concerning the epidemiology of PKU in Jordan are limited. The main objectives of our study were to determine the prevalence of PKU in Jordan, analyze the PKU phenotypes, and identify major challenges in providing dietary management to PKU patients. Methods: Data were collected utilizing the medical records of PKU patients attending the PKU clinic at the Ministry of Health in Amman, Jordan, between 2008 and 2021. Results: The total number of patients diagnosed with PKU was 294. The prevalence of PKU was estimated to be 1/5263. Most patients were Jordanians (90.8%), and 9.2% were non-Jordanians. More than half of the patients (56%) were diagnosed through the national newborn screening (NBS) program. Regarding the phenotypes of PKU, 46.6% had moderate PKU, whereas 42.9% had the classic type of PKU and only 8 (2.7%) had cofactor Tetrahydrobiopterin (BH4) deficiency (atypical PKU). According to the age of diagnosis, 66% of patients were diagnosed more than 30 days post-birth. Consanguinity was found in 87.4% of patients, and the majority of patients, 218 (74.2%), had first-degree consanguinity. The most common complication was mental retardation (31%). Most patients were committed to dietary management (83%) and developed fewer complications. Conclusion: In our study, we demonstrated the importance of the NBS program in the early identification and diagnosis of new PKU cases which allows the initiation of treatment and dietary management to prevent severe complications of PKU in Jordan.
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