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The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1998 Jul 15;102(2):361–370. doi: 10.1172/JCI3112

Molecular genetics of palmitoyl-protein thioesterase deficiency in the U.S.

A K Das 1, C H Becerra 1, W Yi 1, J Y Lu 1, A N Siakotos 1, K E Wisniewski 1, S L Hofmann 1
PMCID: PMC508894  PMID: 9664077

Abstract

Mutations in a newly described lysosomal enzyme, palmitoyl-protein thioesterase (PPT), were recently shown to be responsible for an autosomal recessive neurological disorder prevalent in Finland, infantile neuronal ceroid lipofuscinosis. The disease results in blindness, motor and cognitive deterioration, and seizures. Characteristic inclusion bodies (granular osmiophilic deposits [GROD]) are found in the brain and other tissues. The vast majority of Finnish cases are homozygous for a missense mutation (R122W) that severely affects PPT enzyme activity, and the clinical course in Finnish children is uniformly rapidly progressive and fatal. To define the clinical, biochemical, and molecular genetic characteristics of subjects with PPT deficiency in a broader population, we collected blood samples from U.S. and Canadian subjects representing 32 unrelated families with neuronal ceroid lipofuscinosis who had GROD documented morphologically. We measured PPT activity and screened the coding region of the PPT gene for mutations. In 29 of the families, PPT deficiency was found to be responsible for the neurodegenerative disorder, and mutations were identified in 57 out of 58 PPT alleles. One nonsense mutation (R151X) accounted for 40% of the alleles and was associated with severe disease in the homozygous state. A second mutation (T75P) accounted for 13% of the alleles and was associated with a late onset and protracted clinical course. A total of 19 different mutations were found, resulting in a broader spectrum of clinical presentations than previously seen in the Finnish population. Symptoms first appeared at ages ranging from 3 mo to 9 yr, and about half of the subjects have survived into the second or even third decades of life.

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Selected References

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  1. Camp L. A., Hofmann S. L. Purification and properties of a palmitoyl-protein thioesterase that cleaves palmitate from H-Ras. J Biol Chem. 1993 Oct 25;268(30):22566–22574. [PubMed] [Google Scholar]
  2. Camp L. A., Verkruyse L. A., Afendis S. J., Slaughter C. A., Hofmann S. L. Molecular cloning and expression of palmitoyl-protein thioesterase. J Biol Chem. 1994 Sep 16;269(37):23212–23219. [PubMed] [Google Scholar]
  3. Dyken P., Wisniewski K. Classification of the neuronal ceroid-lipofuscinoses: expansion of the atypical forms. Am J Med Genet. 1995 Jun 5;57(2):150–154. doi: 10.1002/ajmg.1320570208. [DOI] [PubMed] [Google Scholar]
  4. Goebel H. H. The neuronal ceroid-lipofuscinoses. J Child Neurol. 1995 Nov;10(6):424–437. doi: 10.1177/088307389501000602. [DOI] [PubMed] [Google Scholar]
  5. Hellsten E., Vesa J., Olkkonen V. M., Jalanko A., Peltonen L. Human palmitoyl protein thioesterase: evidence for lysosomal targeting of the enzyme and disturbed cellular routing in infantile neuronal ceroid lipofuscinosis. EMBO J. 1996 Oct 1;15(19):5240–5245. [PMC free article] [PubMed] [Google Scholar]
  6. Hofmann S. L., Lee L. A., Lu J. Y., Verkruyse L. A. Palmitoyl-protein thioesterase and the molecular pathogenesis of infantile neuronal ceroid lipofuscinosis. Neuropediatrics. 1997 Feb;28(1):27–30. doi: 10.1055/s-2007-973661. [DOI] [PubMed] [Google Scholar]
  7. Lu J. Y., Verkruyse L. A., Hofmann S. L. Lipid thioesters derived from acylated proteins accumulate in infantile neuronal ceroid lipofuscinosis: correction of the defect in lymphoblasts by recombinant palmitoyl-protein thioesterase. Proc Natl Acad Sci U S A. 1996 Sep 17;93(19):10046–10050. doi: 10.1073/pnas.93.19.10046. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Mitchison H. M., Hofmann S. L., Becerra C. H., Munroe P. B., Lake B. D., Crow Y. J., Stephenson J. B., Williams R. E., Hofman I. L., Taschner P. E. Mutations in the palmitoyl-protein thioesterase gene (PPT; CLN1) causing juvenile neuronal ceroid lipofuscinosis with granular osmiophilic deposits. Hum Mol Genet. 1998 Feb;7(2):291–297. doi: 10.1093/hmg/7.2.291. [DOI] [PubMed] [Google Scholar]
  9. Nevanlinna H. R. The Finnish population structure. A genetic and genealogical study. Hereditas. 1972;71(2):195–236. doi: 10.1111/j.1601-5223.1972.tb01021.x. [DOI] [PubMed] [Google Scholar]
  10. Orita M., Suzuki Y., Sekiya T., Hayashi K. Rapid and sensitive detection of point mutations and DNA polymorphisms using the polymerase chain reaction. Genomics. 1989 Nov;5(4):874–879. doi: 10.1016/0888-7543(89)90129-8. [DOI] [PubMed] [Google Scholar]
  11. Santavuori P., Haltia M., Rapola J. Infantile type of so-called neuronal ceroid-lipofuscinosis. Dev Med Child Neurol. 1974 Oct;16(5):644–653. doi: 10.1111/j.1469-8749.1974.tb04183.x. [DOI] [PubMed] [Google Scholar]
  12. Savukoski M., Kestilä M., Williams R., Järvelä I., Sharp J., Harris J., Santavuori P., Gardiner M., Peltonen L. Defined chromosomal assignment of CLN5 demonstrates that at least four genetic loci are involved in the pathogenesis of human ceroid lipofuscinoses. Am J Hum Genet. 1994 Oct;55(4):695–701. [PMC free article] [PubMed] [Google Scholar]
  13. Schriner J. E., Yi W., Hofmann S. L. cDNA and genomic cloning of human palmitoyl-protein thioesterase (PPT), the enzyme defective in infantile neuronal ceroid lipofuscinosis. Genomics. 1996 Jun 15;34(3):317–322. doi: 10.1006/geno.1996.0292. [DOI] [PubMed] [Google Scholar]
  14. Sharp J. D., Wheeler R. B., Lake B. D., Savukoski M., Järvelä I. E., Peltonen L., Gardiner R. M., Williams R. E. Loci for classical and a variant late infantile neuronal ceroid lipofuscinosis map to chromosomes 11p15 and 15q21-23. Hum Mol Genet. 1997 Apr;6(4):591–595. doi: 10.1093/hmg/6.4.591. [DOI] [PubMed] [Google Scholar]
  15. Sleat D. E., Donnelly R. J., Lackland H., Liu C. G., Sohar I., Pullarkat R. K., Lobel P. Association of mutations in a lysosomal protein with classical late-infantile neuronal ceroid lipofuscinosis. Science. 1997 Sep 19;277(5333):1802–1805. doi: 10.1126/science.277.5333.1802. [DOI] [PubMed] [Google Scholar]
  16. Verkruyse L. A., Natowicz M. R., Hofmann S. L. Palmitoyl-protein thioesterase deficiency in fibroblasts of individuals with infantile neuronal ceroid lipofuscinosis and I-cell disease. Biochim Biophys Acta. 1997 Jul 10;1361(1):1–5. doi: 10.1016/s0925-4439(97)00033-1. [DOI] [PubMed] [Google Scholar]
  17. Vesa J., Hellsten E., Verkruyse L. A., Camp L. A., Rapola J., Santavuori P., Hofmann S. L., Peltonen L. Mutations in the palmitoyl protein thioesterase gene causing infantile neuronal ceroid lipofuscinosis. Nature. 1995 Aug 17;376(6541):584–587. doi: 10.1038/376584a0. [DOI] [PubMed] [Google Scholar]
  18. Wisneiwski K. E., Kida E., Patxot O. F., Connell F. Variability in the clinical and pathological findings in the neuronal ceroid lipofuscinoses: review of data and observations. Am J Med Genet. 1992 Feb 15;42(4):525–532. doi: 10.1002/ajmg.1320420420. [DOI] [PubMed] [Google Scholar]
  19. Wisniewski K. E., Connell F., Kaczmarski W., Kaczmarski A., Siakotos A., Becerra C. R., Hofmann S. L. Palmitoyl-protein thioesterase deficiency in a novel granular variant of LINCL. Pediatr Neurol. 1998 Feb;18(2):119–123. doi: 10.1016/s0887-8994(97)00173-2. [DOI] [PubMed] [Google Scholar]

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