Pantothenate kinase-associated neurodegeneration: Clinical aspects, diagnosis and treatments

Diagnosis and Treatment of Pantothenate Kinase-Associated Neurodegeneration (PKAN): A Systematic Review

A specific type of neurodegeneration with brain iron accumulation (NBIA) falls under the omit phenotypic continuum-early childhood development of progressive pantothenate kinase-associated neurodegeneration (PKAN). Classic PKAN is distinguished from atypical PKAN by stiffness, dystonia, dysarthria, and choreoathetosis. Pigmentary retinal degeneration is a widespread cause of classic PKAN. Atypical PKAN is distinguished by a later onset (>10 years), noticeable speech abnormalities, psychological disorders, and slower disease development. Studies designed to support various PKAN therapeutic strategies have highlighted the intricacy of coenzyme A (CoA) metabolism and the limitations of our present understanding of disease causation. Therefore, improvements in our knowledge of the causes and therapy of PKAN may have ramifications for our comprehension of other, more prevalent diseases. They may also shed fresh light on the physiological significance of CoA, a cofactor essential for the operation of several cellular metabolic processes. The existence of low but considerable PANK2 expression, which can be elevated in some mutations, provides necessary information that can justify using a hefty dose of pantothenate as a treatment. A more effective therapeutic approach can be achieved by comparing the effects of various currently available pharmacological alternatives on the pathophysiological alterations in fibroblasts and neuronal cells obtained from PKAN patients. The objective of this study is to educate and inform people about PKAN disease conditions such as treatment, diagnosis, and complications. These cell models will also help evaluate the effectiveness of future medicinal innovations. This review discusses the neurodegeneration generated by pantothenate kinase in cellular models, iron/lipofuscin in pantothenate kinase-related neurodegeneration, and treatment and diagnosis of PKAN.

Beta-propeller protein-associated neurodegeneration: A clinical update with a case report

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An Updated Overview of the Magnetic Resonance Imaging of Brain Iron in Movement Disorders

Brain iron load is one of the most important neuropathological hallmarks in movement disorders. Specifically, the iron provides most of the paramagnetic metal signals in the brain and its accumulation seems to play a key role, although not completely explained, in the degeneration of the basal ganglia, as well as other brain structures. Moreover, iron distribution patterns have been implicated in depicting different movement disorders. This work reviewed current literature on Magnetic Resonance Imaging for Brain Iron Detection and Quantification (MRI-BIDQ) in neurodegenerative processes underlying movement disorders.

Proton magnetic resonance spectroscopy detects cerebral metabolic derangement in a mouse model of brain coenzyme a deficiency

Background

Pantothenate kinase (PANK) is the first and rate-controlling enzymatic step in the only pathway for cellular coenzyme A (CoA) biosynthesis. PANK-associated neurodegeneration (PKAN), formerly known as Hallervorden–Spatz disease, is a rare, life-threatening neurologic disorder that affects the CNS and arises from mutations in the human PANK2 gene. Pantazines, a class of small molecules containing the pantazine moiety, yield promising therapeutic effects in an animal model of brain CoA deficiency. A reliable technique to identify the neurometabolic effects of PANK dysfunction and to monitor therapeutic responses is needed.

Methods

We applied ¹H magnetic resonance spectroscopy as a noninvasive technique to evaluate the therapeutic effects of the newly developed Pantazine BBP-671.

Results

¹H MRS reliably quantified changes in cerebral metabolites, including glutamate/glutamine, lactate, and N-acetyl aspartate in a neuronal Pank1 and Pank2 double-knockout (SynCre⁺Pank1,2 dKO) mouse model of brain CoA deficiency. The neuronal SynCre⁺Pank1,2 dKO mice had distinct decreases in Glx/tCr, NAA/tCr, and lactate/tCr ratios compared to the wildtype matched control mice that increased in response to BBP-671 treatment.

Conclusions

BBP-671 treatment completely restored glutamate/glutamine levels in the brains of the mouse model, suggesting that these metabolites are promising clinically translatable biomarkers for future therapeutic trials.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-022-03304-y.

Pilot trial on the efficacy and safety of pantethine in children with pantothenate kinase-associated neurodegeneration: a single-arm, open-label study

Objective

This study aimed to explore the efficacy and safety of pantethine in children with pantothenate kinase-associated neurodegeneration (PKAN).

Methods

A single-arm, open-label study was conducted. All subjects received pantethine during the 24-week period of treatment. The primary endpoints were change of the Unified Parkinson’s Disease Rating Scale (UPDRS) I–III and Fahn–Marsden (FM) score from baseline to week 24 after treatment.

Results

Fifteen children with PKAN were enrolled, and all patients completed the study. After 24 weeks of treatment with pantethine at 60 mg/kg per day, there was no difference in either UPDRS I–III (t = 0.516, P = 0.614) or FM score (t = 0.353, P = 0.729) between the baseline and W24. Whereas the rates of increase in UPDRS I-III (Z = 2.614, p = 0.009) and FM scores (Z = 2.643, p = 0.008) were slowed. Four patients (26.7%) were evaluated as “slightly improved” by doctors through blinded video assessment. Patients with lower baseline UPDRS I–III or FM scores were more likely to be improved. The quality of life of family members improved after pantethine treatment, evaluated by PedsQL TM 2.0 FIM scores, whereas the quality of life of the patients was unchanged at W24, evaluated by PedsQL TM 4.0 and PedsQL TM 3.0 NMM. Serum level of CoA was comparable between baseline and W24. There was no drug related adverse event during the study.

Conclusions

Pantethine could not significantly improve motor function in children with PKAN after 24 weeks treatment, but it may delay the progression of motor dysfunction in our study. Pantethine was well-tolerated at 60 mg/kg per day.

Trial registration

Clinical trial registration number at www.chictr.org.cn:ChiCTR1900021076, Registered 27 January2019, the first participant was enrolled 30 September 2018, and other 14 participants were enrolled after the trial was registered.

The roles of iron and HFE genotype in neurological diseases

Iron accumulation is a recurring pathological phenomenon in many neurological diseases including Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and others. Iron is essential for normal development and functions of the brain; however, excess redox-active iron can also lead to oxidative damage and cell death. Especially for terminally differentiated cells like neurons, regulation of reactive oxygen species is critical for cell viability. As a result, cellular iron level is tightly regulated. Although iron accumulation related to neurological diseases has been well documented, the pathoetiological contributions of the homeostatic iron regulator (HFE), which controls cellular iron uptake, is less understood. Furthermore, a common HFE variant, H63D HFE, has been identified as a modifier of multiple neurological diseases. This review will discuss the roles of iron and HFE in the brain as well as their impact on various disease processes.

Natural history and genotype-phenotype correlation of pantothenate kinase-associated neurodegeneration

Aims

To investigate the natural history and genotype‐phenotype correlation of pantothenate kinase‐associated neurodegeneration.

Methods

We collected data of patients with PKAN by searching from available publications in English and Chinese. Patients diagnosed in our center (Peking University First Hospital) were also included. The difference in natural history and genotype between early‐onset (<10 year of age at onset) and late‐onset patients (≥10 year of age at onset) with PKAN was compared.

Results

A total of 248 patients were included. The median age at onset was 3.0 years in the early‐onset group and 18.0 years in the late‐onset group. Dystonia in lower limbs was the most common initial symptom in both groups. In the early‐onset group, the median interval between the disease onset and occurrence of oromandibular dystonia, generalized dystonia, loss of independent ambulance was 6.0 years, 5.0 years, and 5.0 years. The corresponding values in late‐onset group were 1.0 year, 4.0 years, and 6.0 years. About 20.0% died at median age of 12.5 years and 9.5 years after the onset in early‐onset group. About 2.0% of the late‐onset patients died during the follow‐up. A total of 176 mutations were identified. Patients carrying two null alleles in PANK2 showed significantly earlier age of disease onset and progressed more rapidly to loss of independent ambulance.

Conclusions

This study provided a comprehensive review on the natural history and genotype of 248 patients with PKAN. The results will serve as a historical control data for future clinical trial on PKAN.

A novel homozygous variation in the PANK2 gene in two Persian siblings with atypical pantothenate kinase associated neurodegeneration

Pantothenate Kinase-associated Neurodegeneration (PKAN) is an autosomal recessive disorder that is caused by variation in pantothenate kinase-2 gene (PANK2) gene on chromosome 20. The common presentation of this disease includes progressive dystonia, Parkinsonism, retinopathy, cognitive impairment, and spasticity. The typical magnetic resonance imaging finding is eye of the tiger sign in globus pallidus and not pathogenic and not found in all patients. In the present study, we describe two siblings who have a novel variation of the PANK2 gene. These patients with the same genotype, have different ages at the onset of disease and also the various severity of the disease. The description of these cases helps to understand this disease, its symptoms, pathogenesis, and its treatment.