Advertisement

Journal of Inherited Metabolic Disease

, Volume 41, Issue 6, pp 1159–1167 | Cite as

Molecular genetics of a cohort of 635 cases of phenylketonuria in a consanguineous population

  • Tina Shirzadeh
  • Amir Hossein Saeidian
  • Hamideh Bagherian
  • Shadab Salehpour
  • Aria Setoodeh
  • Mohammad Reza Alaei
  • Leila Youssefian
  • Ashraf Samavat
  • Andrew Touati
  • Mohammad-Sadegh Fallah
  • Hassan Vahidnezhad
  • Morteza Karimipoor
  • Sarah Azadmehr
  • Marzieh Raeisi
  • Ameneh Bandehi Sarhadi
  • Fatemeh Zafarghandi Motlagh
  • Mojdeh Jamali
  • Zahra Zeinali
  • Maryam Abiri
  • Sirous Zeinali
  • Additional individual contributors
Original Article

Abstract

Phenylketonuria (PKU) is an inborn error of amino acid metabolism caused by mutations in the phenylalanine hydroxylase (PAH) gene, characterized by intellectual deficit and neuropsychiatric complications in untreated patients with estimated frequency of about one in 10,000 to 15,000 live births. PAH deficiency can be detected by neonatal screening in nearly all cases with hyperphenylalaninemia on a heel prick blood spot. Molecular testing of the PAH gene can then be performed in affected family members. Herein, we report molecular study of 635 patients genetically diagnosed with PKU from all ethnicities in Iran. The disease-causing mutations were found in 611 (96.22%) of cases. To the best of our knowledge, this is the most comprehensive molecular genetics study of PKU in Iran, identifying 100 distinct mutations in the PAH gene, including 15 previously unreported mutations. Interestingly, we found unique cases of PKU with uniparental disomy, germline mosaicism, and coinheritance with another Mendelian single-gene disorder that provides new insights for improving the genetic counseling, prenatal diagnosis (PND), and/or pre-implantation genetic diagnosis (PGD) for the inborn error of metabolism group of disorders.

Keywords

Phenylketonuria Metabolism Consanguinity Genetic counseling 

Notes

Acknowledgements

We would like to thank our colleagues at the National Health Centers throughout the country. Without their referrals this would be incomplete. Our thanks also go to our other colleagues at Dr. Zeinali’s Medical Genetics Lab, KHGRC for doing most of the lab works. We also would like to thank our colleagues at the Genetics Office, Ministry of Health for their advice and support. Last but not least we would like to thank the patients and their families for their sacrifices and giving us their precious blood samples and clinical information. This work was supported financially by KHGRC for which we are grateful.

Additional individual contributors Fatemeh Valizadeh8, Zohreh Sharifi1, Fatemeh Golnabi1, Mehdi Shafaat1.

1Kawsar Human Genetics Research Center, Tehran, Iran.

8Genetics Office, CDC, Ministry of Health of Iran, Tehran, Iran.

Funding

Funding was obtained through the Kawsar Human Genetics Research Center in Tehran, Iran.

Compliance with ethical standards

Conflict of interest

T. Shirzad, A. H. Saeidian, H. Bagherian, S. Salehpour, A. Setoodeh, M. R. Alaei, L. Youssefian, A. Samavat, A. Touati, M-S. Fallah, H. Vahidnezhad, M. Karimipoor, S. Azadmehr, M. Raeisi, A. B. Sarhadi1, F. Zafarghandi, M. Jamali, Z. Zeinali1, M. Abiri, and S. Zeinali declare that they have no conflict of interest.

Supplementary material

10545_2018_228_MOESM1_ESM.xlsx (21 kb)
ESM 1 (XLSX 20 kb)
10545_2018_228_MOESM2_ESM.xlsx (37 kb)
ESM 2 (XLSX 37 kb)
10545_2018_228_MOESM3_ESM.xlsx (11 kb)
ESM 3 (XLSX 11 kb)
10545_2018_228_MOESM4_ESM.xlsx (11 kb)
ESM 4 (XLSX 11 kb)
10545_2018_228_MOESM5_ESM.jpg (3.9 mb)
Supplementary Fig. 1 Correlation between mutation type and neonatal phenylalanine levels. Neonatal phenylalanine levels in cases in this cohort involved in the newborn screening program were organized by the type of mutation (missense, splicing, nonsense) alleles in this cohort for recurrent mutations. The number of phenylalanine levels represents the number of alleles associated with each phenylalanine level in this cohort. Two-sample T-tests between each mutation type showed a significant difference between alleles associated with missense and splicing mutations (p = .005) and missense and nonsense mutations (p = 0.014). No significant difference was present between splicing and nonsense mutations. Recurrent mutations included in this analysis were mutations 2, 6, 19, 30, 45, 48, 49, 54, 55, 62, 63, 70, and 82 numbered as per Fig. 2. (JPG 3953 kb)
10545_2018_228_MOESM6_ESM.jpg (2 mb)
Supplementary Fig. 2 The most common mutations in PAH in this cohort are shown for each ethnic group included in this study. Up to five most common mutations are shown for each ethnic group if present. (JPG 2375 kb)

References

  1. Abiri M, Talebi S, Uitto J et al (2016) Co-existence of phenylketonuria either with maple syrup urine disease or Sandhoff disease in two patients from Iran: emphasizing the role of consanguinity. J Pediat Endocrinol Metab 29:1215–1219Google Scholar
  2. Ajami N, Kazeminezhad SR, Foroughmand AM, Hasanpour M, Aminzadeh M (2013) A preliminary mutation analysis of phenylketonuria in Southwest Iran. Genet Mol Res 12:4958–4966Google Scholar
  3. Amara A, Adala L, Ben Charfeddine I et al (2012) Correlation of SMN2, NAIP, p44, H4F5 and Occludin genes copy number with spinal muscular atrophy phenotype in Tunisian patients. Eur J Paediat Neurol 16:167–174Google Scholar
  4. Ashraf-Samavat FV (2016) Reporting the outcome of national screening and control of phenylketonuria in IranGoogle Scholar
  5. Aulehla-Scholz C, Heilbronner H (2003) Mutational spectrum in German patients with phenylalanine hydroxylase deficiency. Hum Mutat 21:399–400CrossRefGoogle Scholar
  6. Benson G (1999) Tandem repeats finder: a program to analyze DNA sequences. Nucleic Acids Res 27:573–580CrossRefGoogle Scholar
  7. Blau N, Shen N, Carducci C (2014) Molecular genetics and diagnosis of phenylketonuria: state of the art. Expert Rev Mol Diagn 14:655–671CrossRefGoogle Scholar
  8. Bonyadi M, Omrani O, Moghanjoghi SM, Shiva S (2010) Mutations of the phenylalanine hydroxylase gene in Iranian Azeri Turkish patients with phenylketonuria. Genet Test Mol Biomark 14:233–235CrossRefGoogle Scholar
  9. Burgard P, Bremer HJ, Buhrdel P et al (1999) Rationale for the German recommendations for phenylalanine level control in phenylketonuria 1997. Eur J Pediatr 158:46–54CrossRefGoogle Scholar
  10. Chace DH, Millington DS, Terada N, Kahler SG, Roe CR, Hofman LF (1993) Rapid diagnosis of phenylketonuria by quantitative analysis for phenylalanine and tyrosine in neonatal blood spots by tandem mass spectrometry. Clin Chem 39:66–71Google Scholar
  11. Desviat LR, Perez B, Ugarte M (2006) Identification of exonic deletions in the PAH gene causing phenylketonuria by MLPA analysis. Clin Chim Acta 373:164–167CrossRefGoogle Scholar
  12. Gu XF, Zhang M, Chen RG (1995) Phenylketonuria mutations in southern Chinese detected by denaturing gradient gel electrophoresis in exon 7 of PAH gene. J Inherit Metab Dis 18:753–754CrossRefGoogle Scholar
  13. Guldberg P, Levy HL, Hanley WB et al (1996) Phenylalanine hydroxylase gene mutations in the United States: report from the maternal PKU collaborative study. Am J Hum Genet 59:84–94Google Scholar
  14. Habib A, Fallahzadeh MH, Kazeroni HR, Ganjkarimi AH (2010) Incidence of phenylketonuria in southern Iran. Iran J Med Sci 35:3Google Scholar
  15. Hamzehloei T, Hosseini SA, Vakili R, Mojarad M (2012) Mutation spectrum of the PAH gene in the PKU patients from Khorasan Razavi province of Iran. Gene 506:230–232CrossRefGoogle Scholar
  16. Kayaalp E, Treacy E, Waters PJ, Byck S, Nowacki P, Scriver CR (1997) Human phenylalanine hydroxylase mutations and hyperphenylalaninemia phenotypes: a metanalysis of genotype-phenotype correlations. Am J Hum Genet 61:1309–1317CrossRefGoogle Scholar
  17. Kure S, Hou DC, Ohura T et al (1999) Tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency. J Pediatr 135:375–378CrossRefGoogle Scholar
  18. Legendre M, Pochet N, Pak T, Verstrepen KJ (2007) Sequence-based estimation of minisatellite and microsatellite repeat variability. Genome Res 17:1787–1796CrossRefGoogle Scholar
  19. Miller SA, Dykes DD, Polesky HF (1988) A simple salting out procedure for extracting DNA from human nucleated cells. Nucleic Acids Res 16:1215CrossRefGoogle Scholar
  20. den Dunnen JT, Antonarakis SE (2000) Mutation nomenclature extensions and suggestions to describe complex mutations: a discussion. Hum Mutat 15:7–12CrossRefGoogle Scholar
  21. National Institutes of Health Consensus Development Panel (2001) National Institutes of Health consensus development conference statement: phenylketonuria: screening and management, 16–18 October 2000. Pediatrics 108:972–982Google Scholar
  22. Newton CR, Graham A, Heptinstall LE et al (1989) Analysis of any point mutation in DNA. The amplification refractory mutation system (ARMS). Nucleic Acids Res 17:2503–2516CrossRefGoogle Scholar
  23. Saadat M, Ansari-Lari M, Farhud DD (2004) Consanguineous marriage in Iran. Ann Hum Biol 31:263–269CrossRefGoogle Scholar
  24. Schouten JP, McElgunn CJ, Waaijer R, Zwijnenburg D, Diepvens F, Pals G (2002) Relative quantification of 40 nucleic acid sequences by multiplex ligation-dependent probe amplification. Nucleic Acids Res 30:e57CrossRefGoogle Scholar
  25. Setoodeh A, Yarali B, Rabbani A, Khatami S, Shams S (2015) Tetrahydrobiopterin responsiveness in a series of 53 cases of phenylketonuria and hyperphenylalaninemia in Iran. Mol Genet Metab Rep 2:77–79CrossRefGoogle Scholar
  26. Song F, Qu YJ, Zhang T, Jin YW, Wang H, Zheng XY (2005) Phenylketonuria mutations in northern China. Mol Genet Metab 86(Suppl 1):S107–S118CrossRefGoogle Scholar
  27. Szabo RM, Gelberman RH (1985) Operative treatment of cerebral palsy. Hand Clin 1:525–543Google Scholar
  28. Tighe O, Dunican D, O'Neill C et al (2003) Genetic diversity within the R408W phenylketonuria mutation lineages in Europe. Hum Mutat 21:387–393CrossRefGoogle Scholar
  29. Vahidnezhad H, Youssefian L, Zeinali S et al (2017) Dystrophic epidermolysis bullosa: COL7A1 mutation landscape in a multi-ethnic cohort of 152 extended families with high degree of customary consanguineous marriages. J Invest Dermatol 137:660–669CrossRefGoogle Scholar
  30. Vahidnezhad H, Youssefian L, Saeidian AH, et al (2018) Genome-wide single nucleotide polymorphism-based autozygosity mapping facilitates identification of mutations in consanguineous families with epidermolysis bullosa. Exp DermatolGoogle Scholar
  31. Vockley J, Andersson HC, Antshel KM et al (2014) Phenylalanine hydroxylase deficiency: diagnosis and management guideline. Genet Med 16:188–200CrossRefGoogle Scholar
  32. Waters PJ (2003) How PAH gene mutations cause hyper-phenylalaninemia and why mechanism matters: insights from in vitro expression. Hum Mutat 21:357–369CrossRefGoogle Scholar
  33. Weglage J, Wiedermann D, Denecke J et al (2001) Individual blood-brain barrier phenylalanine transport determines clinical outcome in phenylketonuria. Ann Neurol 50:463–467CrossRefGoogle Scholar
  34. Williams RA, Mamotte CD, Burnett JR (2008) Phenylketonuria: an inborn error of phenylalanine metabolism. Clin Biochem Rev 29:31–41Google Scholar
  35. Yilmaz E, Cali F, Roman V et al (2000) Molecular basis of mild hyperphenylalaninaemia in Turkey. J Inherit Metab Dis 23:523–525CrossRefGoogle Scholar
  36. Youssefian L, Vahidnezhad H, Saeidian AH et al (2017) Autosomal recessive congenital ichthyosis: CERS3 mutations identified by a next generation sequencing panel targeting ichthyosis genes. Eur J Human Genet 25:1282–1285Google Scholar
  37. Zare-Karizi S, Hosseini-Mazinani SM, Khazaei-Koohpar Z et al (2011) Mutation spectrum of phenylketonuria in Iranian population. Mol Genet Metab 102:29–32CrossRefGoogle Scholar
  38. Zschocke J (2003) Phenylketonuria mutations in Europe. Hum Mutat 21:345–356CrossRefGoogle Scholar
  39. Zurfluh MR, Zschocke J, Lindner M et al (2008) Molecular genetics of tetrahydrobiopterin-responsive phenylalanine hydroxylase deficiency. Hum Mutat 29:167–175CrossRefGoogle Scholar

Copyright information

© SSIEM 2018

Authors and Affiliations

  1. 1.Kawsar Human Genetics Research CenterTehranIran
  2. 2.Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaUSA
  3. 3.Genetic, Genomics and Cancer Biology PhD ProgramThomas Jefferson UniversityPhiladelphiaUSA
  4. 4.Department of Pediatric Endocrinology and Metabolism, Mofid Children’s HospitalShahid Beheshti University of Medical SciencesTehranIran
  5. 5.Genomic Research CenterShahid Beheshti University of Medical SciencesTehranIran
  6. 6.Growth and Development Research CenterTehran University of Medical SciencesTehranIran
  7. 7.Department of PediatricsTehran University of Medical SciencesTehranIran
  8. 8.Department of Medical Genetics, School of MedicineTehran University of Medical SciencesTehranIran
  9. 9.Genetics Office, CDCMinistry of Health of IranTehranIran
  10. 10.Drexel University College of MedicinePhiladelphiaUSA
  11. 11.Department of Molecular Medicine, Biotechnology Research CenterPasteur Institute of IranTehranIran
  12. 12.Research Institute for Endocrine ScienceShahid Beheshti University of Medical SciencesTehranIran
  13. 13.Department of cellular and molecular biologyIslamic Azad University North Tehran branchTehranIran
  14. 14.Department of Medical Genetics, School of MedicineIran University of Medical SciencesTehranIran
  15. 15.Department of Molecular Medicine, Biotech Research CenterPasteur Institute of IranTehranIran

Personalised recommendations