p.L1795F LRRK2 variant is a common cause of Parkinson's disease in Central Europe.

Pathogenic variants in LRRK2 are one of the most common genetic risk factors for Parkinson's disease (PD). Recently, the lesser-known p.L1795F variant was proposed as a strong genetic risk factor for PD, however, further families are currently lacking in literature. A multicentre young onset and familial PD cohort (n = 220) from 9 movement disorder centres across Central Europe within the CEGEMOD consortium was screened for rare LRRK2 variants using whole exome sequencing data. We identified 4 PD cases with heterozygous p.L1795F variant. All 4 cases were characterised by akinetic-rigid PD phenotype with early onset of severe motor fluctuations, 2 receiving LCIG therapy and 2 implanted with STN DBS; all 4 cases showed unsatisfactory effect of advanced therapies on motor fluctuations. Our data also suggest that p.L1795F may represent the most common currently known pathogenic LRRK2 variant in Central Europe compared to the more studied p.G2019S, being present in 1.81% of PD cases within the Central European cohort and 3.23% of familial PD cases. Together with the ongoing clinical trials for LRRK2 inhibitors, this finding emphasises the urgent need for more ethnic diversity in PD genetic research.

[Transthyretin familial amyloid polyneuropathy - three Hungarian cases with rare mutations (His88Arg and Phe33Leu)]. / Transthyretin familiáris amyloid polyneuropathia - három magyarországi eset ritka mutációkkal (His88Arg és Phe33Leu).

Introduction - Transthyretin familial amyloid polyneuropathy is a rare autosomal dominant progressive systemic disesase of adults caused by endoneural amyloid deposition due to point mutations of the transthyretin gene. It is the most severe form among hereditary polyneuropathies, being fatal within 10 years if left untreated. The disease is underdiagnosed, the late onset forms (above the age of 50) being probably more widespread than previously thought. Early diagnosis is essential as the early introduction of causal therapy (tafamidis) slows progression and prolongs survival. Patients - We report here three non-related Hungarian cases of transthyretin familial amyloid polyneuropathy with non-Val30Met mutations (His88Arg in two cases, Phe33Leu in one case). They were all characterized by late-onset, progressive, length-dependent, axonal, sensorimotor polyneuropathy and the simultaneous presentation of severe restrictive cardiomyopathy. In all three cases, clinical and electrophysiological signs of myopathy were also present, suggesting the involvement of skeletal muscles as well. In two cases, high resolution ultrasound of the peripheral nerves was also performed, which showed segmental structural alterations (change or loss of fascicular structure) and some increase of echogenicity of the interfascicular epineurium, without substantial enlargement of the nerves. Conclusion - In Hungary, mainly the rare, non-Val30Met mutation forms of transthyretin familial amyloid polyneuropathy are encountered, as in our cases. As opposed to the Val30Met forms, these mutations are characterized by late onset and simultaneous presentation of severe cardiomyopathy. Our report highlights the importance of considering transthyretin familial amyloid polyneuropathy in the differential diagnosis of late-onset, progressive, axonal polyneuropathies of unknown etiology, particularly if associated with cardiac disease.

Gaucher disease type I complicated with Parkinson's syndrome.

Gaucher disease type I is the so-called non-neuronal adult form of the autosomally inherited lysosomal storage disease. The simultaneous occurrence of Gaucher disease with Parkinson's syndrome has been reported to aggravate both disorders, leading to an unusually early onset and therapy resistance. Neurological alterations in Gaucher disease type I are mostly related to CNS bleeding and skeletal complications. The patient presented here was sensitive to combination therapy for 5 years.