Cognitive and behavioral profile of Perry syndrome in two families

Perry Disease: Current Outlook and Advances in Drug Discovery Approach to Symptomatic Treatment

Perry disease (PeD) is a rare, neurodegenerative, genetic disorder inherited in an autosomal dominant manner. The disease manifests as parkinsonism, with psychiatric symptoms on top, such as depression or sleep disorders, accompanied by unexpected weight loss, central hypoventilation, and aggregation of DNA-binding protein (TDP-43) in the brain. Due to the genetic cause, no causal treatment for PeD is currently available. The only way to improve the quality of life of patients is through symptomatic therapy. This work aims to review the latest data on potential PeD treatment, specifically from the medicinal chemistry and computer-aided drug design (CADD) points of view. We select proteins that might represent therapeutic targets for symptomatic treatment of the disease: monoamine oxidase B (MAO-B), serotonin transporter (SERT), dopamine D2 (D2R), and serotonin 5-HT1A (5-HT1AR) receptors. We report on compounds that may be potential hits to develop symptomatic therapies for PeD and related neurodegenerative diseases and relieve its symptoms. We use Phase pharmacophore modeling software (version 2023.08) implemented in Schrödinger Maestro as a ligand selection tool. For each of the chosen targets, based on the resolved protein-ligand structures deposited in the Protein Data Bank (PDB) database, pharmacophore models are proposed. We review novel, active compounds that might serve as either hits for further optimization or candidates for further phases of studies, leading to potential use in the treatment of PeD.

ALS-plus related clinical and genetic study from China

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder. An increasing number of researchers have found extra motor features in ALS, which are also called ALS-plus syndromes. Besides, a great majority of ALS patients also have cognitive impairment. However, clinical surveys of the frequency and genetic background of ALS-plus syndromes are rare, especially in China.

METHODS

We investigated a large cohort of 1015 patients with ALS, classifying them into six groups according to different extramotor symptoms and documenting their clinical manifestations. Meanwhile, based on their cognitive function, we divided these patients into two groups and compared demographic characteristics. Genetic screening for rare damage variants (RDVs) was also performed on 847 patients.

RESULTS

As a result, 16.75% of patients were identified with ALS-plus syndrome, and 49.5% of patients suffered cognitive impairment. ALS-plus group had lower ALSFRS-R scores, longer diagnostic delay time, and longer survival times, compared to ALS pure group. RDVs occurred less frequently in ALS-plus patients than in ALS-pure patients (P = 0.042) but showed no difference between ALS-cognitive impairment patients and ALS-cognitive normal patients. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus symptoms than ALS-cognitive normal group (P = 0.001).

CONCLUSION

In summary, ALS-plus patients in China are not rare and show multiple differences from ALS-pure patients in clinical and genetic features. Besides, ALS-cognitive impairment group tends to harbour more ALS-plus syndrome than ALS-cognitive normal group. Our observations correspond with the theory that ALS involves several diseases with different mechanisms and provide clinical validation.

Perry Disease: Expanding the Genetic Basis

Background

Perry disease (or Perry syndrome [PS]) is a hereditary neurodegenerative disorder inevitably leading to death within few years from onset. All previous cases with pathological confirmation were caused by mutations within the cytoskeleton-associated protein glycine-rich (CAP-Gly) domain of the DCTN1 gene.

Objectives

This paper presents the first clinicopathological report of PS due to a novel DCTN1 mutation outside the CAP-Gly domain.

Methods

Clinical and pathological features of the new variant carrier are compared with another recently deceased PS case with a well-known pathogenic DCTN1 mutation and other reported cases.

Results and Conclusions

We report a novel DCTN1 mutation outside the CAP-Gly domain that we demonstrated to be pathogenic based on clinical and autopsy findings.

Perry syndrome: Novel DCTN1 mutation in a large kindred and first observation of prodromal disease

INTRODUCTION

Perry syndrome (PS) is a hereditary neurodegenerative disorder caused by mutations in the DCTN1 gene and characterized by TDP-43 pathology. As the diagnosis is usually made at the advanced stages of the disease, there are no studies on the asymptomatic mutation carriers and their conversion to overt disease.

METHODS

We personally examined 27 members of the large kindred of 104 individuals with familial parkinsonism. We evaluated each case with clinical (neurological examination; motor and non-motor scales), genetic testing (whole-exome or Sanger sequencing), and laboratory (neurofilament light, NFL; glial fibrillary acidic protein, GFAP) measures. Autopsy study was done on two individuals.

RESULTS

The mean age at evaluation was 49 years. Comorbidities were present in 20 cases, including sleep problems (n = 15 total, sleep apnea in 7), dysautonomia (n = 10), weight loss (n = 8), and anxiety/depression (n = 8). Neurological abnormalities were present in 18, including parkinsonism (n = 7), isolated tremor (n = 2), and varied isolated signs in individual cases. Cognition and smell were preserved. Genetic testing revealed a novel c.200G > T (Gly67Val) mutation in the DCTN1 gene in 10 individuals. The mutation, segregated with the PS phenotype (n = 4), was absent in gnomAD, and in silico predictions indicated it was pathogenic. Three young mutation carriers were monosymptomatic (prodromal), and three were asymptomatic. Plasma NFL and GFAP values were similar among the cases. Autopsy studies showed typical PS neuropathological findings.

CONCLUSIONS

We identified a novel pathogenic Gly67Val DCTN1 mutation. We report prodromal disease of PS in some mutation carriers; however, more investigation is necessary to confirm this observation.

L-Dopa response, choreic dyskinesia, and dystonia in Perry syndrome

INTRODUCTION

A marked response to L-Dopa and L-Dopa-induced dyskinesia (LID) make the diagnosis of Parkinson's disease (PD) highly likely. This paper evaluates response to L-Dopa in Perry syndrome (PS), parkinsonism with distinct molecular and neuropathologic characteristics.

METHODS

Six patients with PS with a mean follow-up of 5 years (0.5-12) were assessed by movement disorder specialists and video recorded in states off and on. Additionally, DATSCAN-SPECT was performed in 3 subjects.

RESULTS

Four patients displayed a marked and sustained response to L-Dopa and LID. Additionally, we observed a distinct pattern of off-state predominant craniocervical dystonia responsive to L-Dopa in 4 patients, truncal dystonia in one, and dystonic head tremor in another. DATSCAN-SPECT was abnormal in 3 patients.

CONCLUSIONS

Patients with PS may present PD-like parkinsonism with a marked and sustained response to L-Dopa and LID. The characteristic pattern of craniocervical dystonia may be a helpful clue to the diagnosis of PS.

Parkin beyond Parkinson’s Disease—A Functional Meaning of Parkin Downregulation in TDP-43 Proteinopathies

Parkin and PINK1 are key regulators of mitophagy, an autophagic pathway for selective elimination of dysfunctional mitochondria. To this date, parkin depletion has been associated with recessive early onset Parkinson’s disease (PD) caused by loss-of-function mutations in the PARK2 gene, while, in sporadic PD, the activity and abundance of this protein can be compromised by stress-related modifications. Intriguingly, research in recent years has shown that parkin depletion is not limited to PD but is also observed in other neurodegenerative diseases—especially those characterized by TDP-43 proteinopathies, such as amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Here, we discuss the evidence of parkin downregulation in these disease phenotypes, its emerging connections with TDP-43, and its possible functional implications.

Clinical, pathological and genetic characteristics of Perry disease-new cases and literature review

BACKGROUND AND PURPOSE

Perry disease (or Perry syndrome) is an autosomal dominant neurodegenerative disorder characterized by parkinsonism, neuropsychiatric symptoms, central hypoventilation, weight loss and distinct TDP-43 pathology. It is caused by mutations of the DCTN1 gene encoding an essential component of axonal transport. The objectives were to provide the current state of knowledge on clinical, pathological and genetic aspects of Perry disease, as well as practical suggestions for the management of the disease.

METHODS

Data on new patients from New Zealand, Poland and Colombia were collected, including autopsy report. Also all of the published papers since the original work by Perry in 1975 were gathered and analyzed.

RESULTS

Parkinsonism was symmetrical, progressed rapidly and was poorly responsive to L-Dopa; nonetheless, a trial with high doses of L-Dopa is warranted. Depression was severe, associated with suicidal ideations, and benefited from antidepressants and L-Dopa. Respiratory symptoms were the leading cause of death, and artificial ventilation or a diaphragm pacemaker prolonged survival. Weight loss occurred in most patients and was of multifactorial etiology. Autonomic dysfunction was frequent but underdiagnosed. There was a clinical overlap with other neurodegenerative disorders. An autopsy showed distinctive pallidonigral degeneration with TDP-43 pathology. Genetic testing provided evidence of a common founder for two families. There was striking phenotypic variability in DCTN1-related disorders. It is hypothesized that oligogenic or polygenic inheritance is at play.

CONCLUSIONS

Perry disease and other DCTN1-related diseases are increasingly diagnosed worldwide. Relatively effective symptomatic treatments are available. Further studies are needed to pave the way toward curative/gene therapy.