Skip Navigation
Skip to contents

JMD : Journal of Movement Disorders

OPEN ACCESS
SEARCH
Search

Articles

Page Path
HOME > J Mov Disord > Volume 2(1); 2009 > Article
Case Report
Novel Compound Heterozygous Mutations in the Pantothenate Kinase 2 Gene in a Korean Patient with Atypical Pantothenate Kinase Associated Neurodegeneration
Sung-Hyouk Kima, Young-Hee Sunga, Kee-Hyung Parka, Yeung-Bae Leea, Hyeon-Mi Parka, Dong Jin Shina, Gu-Hwan Kimb
Journal of Movement Disorders 2009;2(1):45-47.
DOI: https://doi.org/10.14802/jmd.09012
Published online: April 30, 2009

aDepartment of Neurology, Gachon University Gil Hospital, Incheon, Korea

bMedical Genetics Clinic, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea

Corresponding author: Young-Hee Sung, MD, Department of Neurology, Gachon University Gil Hospital, 1198 Guwol-dong, Namdong-gu, Incheon 405-760, Korea, Tel +82-32-460-3346, Fax +82-32-460-3344, E-mail atmann02@gilhospital.com
• Received: March 16, 2009   • Revised: March 28, 2009   • Accepted: March 20, 2009

Copyright © 2009 The Korean Movement Disorder Society

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

prev next
  • 22,134 Views
  • 80 Download
  • 2 Crossref
  • Pantothenate kinase-associated neurodegeneration (PKAN) is an autosomal recessive disorder that is characterized by mutations in the pantothenate kinase 2 gene (PANK2) and typical magnetic resonance imaging findings. We report a case of atypical PKAN presenting with generalized dystonia. Our patient had compound heterozygous mutations in the PANK2 gene, including mutation in exon 3 (p.D268G) and exon 4 (p.R330P). To our knowledge, this patient is the first to have the p.R330P mutation and the second to have the p.D268G mutation.
Pantothenate kinase-associated neurodegeneration (PKAN), the major form of neurodegeneration with brain iron accumulation (NBIA), is an autosomal recessive disorder that is characterized by mutations in the pantothenate kinase 2 gene (PANK2) and typical magnetic resonance imaging (MRI) findings.1 PKAN is classified into the classic form and an atypical form based on age at onset and rate of disease progression. The classic form usually presents in first decade of life and progresses rapidly to loss of ambulation within 10–15 years after onset. The clinical features of atypical PKAN are heterogeneous, but patients with this form commonly present in the second or third decade of life, and loss of ambulation occurs within 15–40 years after onset.2 We report the case of a patient with late-onset generalized dystonia who has a novel compound heterozygous mutations in the PANK2 gene.
A 40-year-old man presented with involuntary movement of his right hand and left foot. The symptom started when he was approximately 35 years of age and had slowly worsened. Initially, his gait became unsteady. His disability progressed over the following years and was restricted to his right hand and left foot. The patient had been working as stonemason for the last 20 years. He had no significant medical history and no history of exposure to neuroleptic drugs, hypoxic environments, or toxic metabolites, except for the intermittent inhalation of silica dust at his workplace. There was no family history of neurological disorders.
On examination, the patient had dystonic posture of his right hand, which caused alternating dorsiflexion and neutralization with supination of the forearm and flexion of the metacarpophalangeal joint. He had fixed plantar flexion and intermittent inversion dystonia of his left foot. His gait was markedly spastic. The results of neuropsychological tests showed normal cognitive function. An ophthalmologic evaluation showed no Kayser-Fleischer rings, optic atrophy, or pigmentary retinopathy. The results of a nerve conduction study were normal. Serum ferritin and copper levels were normal, and a blood smear was negative for acanthocytes. The results of other laboratory tests, including serum electrolytes, erythrocyte sedimentation rate, thyroid function test, liver function test, autoimmune antibodies, ferritin, copper, ceruloplasmin, and a blood smear were normal, except for borderline-low 24-hour urine copper (10.2 μg/dL, normal 15–30 μg/dL).
A T1-weighted brain MRI study showed hyperintensity bilateral anteromedial globus pallidi (Figure 1A). A T2-weighted MRI showed hypointensity in the bilateral globus pallidi with hyperintense core, the typical “eye-of-the-tiger” sign (Figure 1B).
Genomic DNA was extracted from peripheral blood, and polymerase chain reactions (PCR) were preformed. The DYT1 GAG deletion (delE302/303) was not found. Seven exons in the PANK2 gene were analyzed by PCR (Figure 2). Automated DNA sequence analyses revealed two single-base variants in exon 3 and exon 4. Both pathological variants result in changes to conserved amino acids in the PANK2 protein: Asp268→ Gly (p.D268G) and Arg330→Prp (p.R330P). To our knowledge, this is the first patient identified with the mutation p. R330P and the second patient with the mutation p.D268G.
The dystonia of the patient’s right hand and left foot did not respond to levodopa/carbidopa (100/25 mg t.i.d). Treatment with diazepam (5 mg t.i.d) and trihexyphenidyl (2 mg t.i.d) slightly improved the dystonia. However, his dystonia worsened after one year, and he could not walk without a cane.
Our patient had an atypical phenotype of the PANK2 gene: compound heterozygous mutations in exon 3 (p.D268G) and exon 4 (p.R330P). To our knowledge, our patient is the first to be identified with mutation p.R330P and the second to be identified with mutation p.D268G.
The onset of atypical PKAN is known to be 1st three decades (mean age 13.6).2 In a previous study, 23 patients with atypical PKAN were analyzed, and the mean age at onset was 13.7 years (range 1–28 years). Patients with atypical PKAN had variable clinical features, including parkinsonism, corticospinal tract involvement, speech disturbances such as palilalia, and psychiatric symptoms.3 Our patient presented with dystonia and gait disturbance, which are the predominant symptoms of classical PKAN.
The implication of the “eye-of-the-tiger” sign on a brain MRI is controversial.3,4 The “eye-of-the-tiger” sign on MRI is not pathognomic of PKAN, and some patients with PANK2 mutations do not have this sign and sometimes, it may appear only transiently. This sign has also been reported in corticobasal degeneration, progressive supranuclear palsy, anoxicischemic leukoencephalopathy, and early-onset levodopa-responsive parkinsonism.4 However, a previous study reported that all patients clinically suspected of NBIA with the “eye-of-tigersign” have mutations in PANK2 and that all patients without the typical MRI finding do not have these mutations.3 In our patient, the MRI finding and presenting symptoms were consistent with classic PKAN, while the age at onset and the absence of other features such as retinal degeneration, optic atrophy, and delayed development were consistent with atypical disease or other subtypes of NBIA.
Genetic studies identified compound heterozygous missense mutations (p.D268G, p.R330P) in exons 3 and 4 of PANK2. To our knowledge, this is the first description of the p.R330P mutation. The mutation p.D268G was reported previously in a Chinese patient with heterozygous missense mutations (p. D268G, p.I391N).5 Others have attempted to establish a correlation between the genotype and phenotype. Although the linkage between mutations and residual enzymatic activities related to the age of onset has been partially demonstrated, the phenotype is still difficult to predict based on the presence of PANK2 mutations.3,68 There were no overlapping clinical features between our patient and the Chinese patient with the p.D268G mutation, except for the typical MRI finding. The Chinese patient’s disease began at 17 years of age, and his predominant symptoms were tremor and rigidity. It is presumed that modifier effects of allelic genes and environmental factors played a roll in the phenotypic differences between these two patients.3
The PANK2 gene codes for pantothenate kinase, which is an essential regulatory enzyme in coenzyme A (CoA) biosynthesis, catalyzing the cytosolic phosphorylation of pantothenate (vitamin B5) the enzyme of the initial and rate-limiting step in CoA biosynthesis: the phosphorylation of pantothenate, N-pantothenoyl-cysteine and pantetheine.9 To compensate for the partial enzymatic deficiency in patients with PKAN, supplement of pantothenate (vitamin B5) have been tried without conclusive benefit.3 Previous case reports using pallidal deep-brain stimulation reported improvement of dystonia in patients with PKAN, but it was also restrictive effect.10 Further study is needed for early diagnosis of PKAN, correct prediction of disease progress, and rational treatment.
Figure 1.
Axial brain MRI of the patient with compound heterozygous PANK2 mutations. A: T1-weighted brain MRI showed hyperintensity bilateral anteromedial globus pallidi. B: T2-weighted MRI showed hypointensity in the bilateral globus pallidi with hyperintense core, the typical “eye-of-the-tiger” sign.
jmd-2-1-45-12f1.gif
Figure 2.
Automated DNA sequence analyses revealed two single-base variants in exon 3 and exon 4 in the PANK2 gene. Both pathological variants result in changes to conserved amino acids in the PANK2 protein: Asp268→Gly (p.D268G) and Arg330→Prp (p. R330P).
jmd-2-1-45-12f2.gif
  • 1. McNeill A, Birchall D, Hayflick SJ, Gregory A, Schenk JF, Zimmerman EA, et al. T2* and FSE MRI distinguishes four subtypes of neurodegeneration with brain iron accumulation. Neurology 2008;70:1614–1619.ArticlePubMedPMC
  • 2. Gregory AM, Hayflick SJ. Neurodegeneration with brain iron accumulation. Orphanet Encyclopedia; 2004 Sep. Available from: URL: http://www.orpha.net/data/patho/GB/uk-NBIA.pdf. Article
  • 3. Hayflick SJ, Westaway SK, Levinson B, Zhou B, Johnson MA, Ching KH, et al. Genetic, clinical, and radiographic delineation of Hallervorden-Spatz syndrome. N Engl J Med 2003;348:33–40.ArticlePubMed
  • 4. Gordon N. Pantothenate kinase-associated neurodegeneration (Hallervorden-Spatz syndrome). Eur J Paediatr Neurol 2002;6:243–247.ArticlePubMed
  • 5. Zhang YH, Tang BS, Zhao AL, Xia K, Long ZG, Guo JF, et al. Novel compound heterozygous mutations in the PANK2 gene in a Chinese patient with atypical pantothenate kinase-associated neurodegeneration. Mov Disord 2005;20:819–821.ArticlePubMedPMC
  • 6. Hartig MB, Hőrtnagel K, Garavaglia B, Zorzi G, Kmiec T, Klopstock T, et al. Genotypic and phenotypic spectrum of PANK2 mutations in patients with neurodegeneration with brain iron accumulation. Ann Neurol 2006;59:248–256.ArticlePubMed
  • 7. Matarin MM, Singleton AB, Houlden H. PANK2 gene analysis confirms genetic heterogeneity in neurodegeneration with brain iron accumulation (NBIA) but mutations are rare in other types of adult neurodegerative disease. Neurosci Lett 2006;407:162–165.ArticlePubMed
  • 8. Pellecchia MT, Valente EM, Cif L, Salvi S, Albanese A, Scarano V, et al. The diverse phenotype and genotype of pantothenate kinase-associated neurodegeneration. Neurology 2005;64:1810–1812.ArticlePubMed
  • 9. Zhou B, Westaway SK, Levinson B, Johnson MA, Gitschier J, Hayflick SJ. A novel pantothenate kinase gene (PANK2) is defective in Hallervorden-Spatz syndrome. Nat Genet 2001;28:345–349.Article
  • 10. Shields DC, Sharma N, Gale JT, Eskandar EN. Pallidal stimulation for dystonia in Pantothenate kinase-associated neurodegeneration. Pediatr Neurol 2007;37:442–445.ArticlePubMed

Figure & Data

References

    Citations

    Citations to this article as recorded by  
    • Atypical pantothenate kinase-associated neurodegeneration: Clinical description of two brothers and a review of the literature
      S. Mahoui, A. Benhaddadi, W. Ameur El Khedoud, M. Abada Bendib, M. Chaouch
      Revue Neurologique.2017; 173(10): 658.     CrossRef
    • Clinical Heterogeneity of Atypical Pantothenate Kinase-Associated Neurodegeneration in Koreans
      Jae-Hyeok Lee, Jongkyu Park, Ho-Sung Ryu, Hyeyoung Park, Young Eun Kim, Jin Yong Hong, Sang Ook Nam, Young-Hee Sung, Seung-Hwan Lee, Jee-Young Lee, Myung Jun Lee, Tae-Hyoung Kim, Chul Hyoung Lyoo, Sun Ju Chung, Seong Beom Koh, Phil Hyu Lee, Jin Whan Cho,
      Journal of Movement Disorders.2016; 9(1): 20.     CrossRef

    Comments on this article

    Add a comment
    Figure
    • 0
    • 1
    Related articles
    Novel Compound Heterozygous Mutations in the Pantothenate Kinase 2 Gene in a Korean Patient with Atypical Pantothenate Kinase Associated Neurodegeneration
    Image Image
    Figure 1. Axial brain MRI of the patient with compound heterozygous PANK2 mutations. A: T1-weighted brain MRI showed hyperintensity bilateral anteromedial globus pallidi. B: T2-weighted MRI showed hypointensity in the bilateral globus pallidi with hyperintense core, the typical “eye-of-the-tiger” sign.
    Figure 2. Automated DNA sequence analyses revealed two single-base variants in exon 3 and exon 4 in the PANK2 gene. Both pathological variants result in changes to conserved amino acids in the PANK2 protein: Asp268→Gly (p.D268G) and Arg330→Prp (p. R330P).
    Novel Compound Heterozygous Mutations in the Pantothenate Kinase 2 Gene in a Korean Patient with Atypical Pantothenate Kinase Associated Neurodegeneration

    JMD : Journal of Movement Disorders Twitter
    Close layer
    TOP