The Association Between Lysosomal Storage Disorder Genes and Parkinson’s Disease: A Large Cohort Study in Chinese Mainland Population

Background: Recent years have witnessed an increasing number of studies indicating an essential role of the lysosomal dysfunction in Parkinson’s disease (PD) at the genetic, biochemical, and cellular pathway levels. In this study, we investigated the association between rare variants in lysosomal storage disorder (LSD) genes and Chinese mainland PD.Methods: We explored the association between rare variants of 69 LSD genes and PD in 3,879 patients and 2,931 controls from Parkinson’s Disease & Movement Disorders Multicenter Database and Collaborative Network in China (PD-MDCNC) using next-generation sequencing, which were analyzed by using the optimized sequence kernel association test.Results: We identified the significant burden of rare putative LSD gene variants in Chinese mainland patients with PD. This association was robust in familial or sporadic early-onset patients after excluding the GBA variants but not in sporadic late-onset patients. The burden analysis of variant sets in genes of LSD subgroups revealed a suggestive significant association between variant sets in genes of sphingolipidosis deficiency disorders and familial or sporadic early-onset patients. In contrast, variant sets in genes of sphingolipidoses, mucopolysaccharidoses, and post-translational modification defect disorders were suggestively associated with sporadic late-onset patients. Then, SMPD1 and other four novel genes (i.e., GUSB, CLN6, PPT1, and SCARB2) were suggestively associated with sporadic early-onset or familial patients, whereas GALNS and NAGA were suggestively associated with late-onset patients.Conclusion: Our findings supported the association between LSD genes and PD and revealed several novel risk genes in Chinese mainland patients with PD, which confirmed the importance of lysosomal mechanisms in PD pathogenesis. Moreover, we identified the genetic heterogeneity in early-onset and late-onset of patients with PD, which may provide valuable suggestions for the treatment.

Hyo-Mental Angle and Distance: An Important Adjunct in Airway Assessment of Adult Mucopolysaccharidosis

Background: Mucopolysaccharidosis (MPS) is a rare congenital lysosomal storage disorder with complex airways. High anterior larynx is assessed by thyromental distance (TMD) nasendoscopy. A simpler method to assess this hyoid bone is described. The distance between the central-hyoid and symphysis of the mandible (hyo-mental distance; HMD) and inclination of this line to the horizontal axis (hyo-mental angle; HMA) in neutrally positioned patients is investigated. Methods: HMA, HMD in MPS, and non-MPS were compared, and their correlation with height and weight were assessed. Results: 50 adult MPS patients (M = 32, F = 18, age range = 19–66 years; mean BMI = 26.8 kg/m2) of MPS I, II, III, IV, and VI were compared with 50 non-MPS (M = 25, F = 25; age range = 22–84 years; mean BMI = 26.5 kg/m2). Mean HMA in MPS was 25.72° (−10 to +50) versus 2.42° (−35 to +28) in non-MPS. Mean HMD was 46.5 (25.7–66) millimeters in MPS versus 41.8 (27–60.3) in non-MPS. HMA versus height and weight showed a moderate correlation (r = −0.4, p < 0.05) in MPS and no significant correlation (r < 0.4, p > 0.05) in non-MPS. HMD versus height and weight showed no correlation (r < 0.4, p > 0.05) in both groups. Conclusions: HMA seems more acute in MPS despite nearly the same HMD as non-MPS, signifying a high larynx, which may be missed by TMD.

Formation of multinucleated globoid cells in Krabbe iPSC-derived microglia cultures: a preliminary investigation

Globoid cell leukodystrophy (Krabbe disease) is a severe demyelinating, neurodegenerative lysosomal storage disorder caused by deficiency in glycosphingolipid catabolic enzyme galactosylceramidase (GALC). Histologically, Krabbe disease is characterized by the appearance of large multinucleated globoid cells that express classical macrophage markers (both of brain-resident microglia and peripheral monocyte-derived). Globoid cells reside near areas of degeneration; however, their functional significance in disease progression remains unclear. In the current study, we differentiated microglia-like cells from iPSCs from a donor with infantile Krabbe disease and compared them to microglia generated from two healthy controls and two donors with the lysosomal storage disorder metachromatic leukodystrophy (MLD), which is genetically distinct from Krabbe disease but presents similarly in terms of severity of demyelination and neurodegeneration. We report the novel finding of prominent formation of giant multinucleated globoid cells from the microglia derived from the Krabbe donor, but not from healthy control or MLD donors. The Krabbe microglia displayed reduced IL-6 protein expression upon stimulation with lipopolysaccharide, and the multinucleated globoid cells themselves appeared deficient in phagocytosis of both disease-relevant myelin debris and E. coli, together hinting at an impairment of normal function. The formation of the globoid cells could be attenuated by fully replacing the medium following passaging, suggesting that yet-to-be determined secreted factors are influencing cell fusion in our culture system. While preliminary, our results imply that globoid cells may be detrimental in Krabbe disease by hindering the normal function of brain-residing macrophages.

Anaesthetic implications for splenectomy in a child with Gaucher’s disease

Gaucher’s disease, a lysosomal storage disorder, is caused by an inherited deficiency of beta glucocerebrosidase enzyme leading to the accumulation of glucocerebroside in the reticuloendothelial system. Patients with this disease often manifest coagulation abnormalities and multi-organ complications. These factors present a challenge to the anaesthesiologist, in deciding the type as well as the conduct of anaesthesia. We aim to report the anaesthetic management in a 3-years old child with Gaucher’s disease posted for splenectomy.

Carlos II of Spain, ‘The Bewitched’: cursed by aspartylglucosaminuria?

Carlos II of Spain (1661–1700), last of the Spanish Habsburgs, was known as The ‘Bewitched’ due to his multiple medical issues and feeble nature. He suffered from a range of ailments extending beyond the well-known Habsburg jaw, including developmental delay, intellectual disability, dysarthria, skeletal deformity, recurrent infections, epilepsy and infertility, among others. The Habsburg dynasty of Spain was characterised by marked inbreeding, and the male line died out with Carlos II. Various diagnoses have been proffered to explain Carlos II’s infirmity, though none have been full satisfactory to explain the full breadth of his ailments. As illustrated here, it may be that aspartylglucosaminuria, an autosomal recessively inherited lysosomal storage disorder, can account for both the characteristic facial features and the wide variety of other features exhibited by Carlos II.

Infantile Galactosialidosis with Novel Mutation: An Early Presentation

Galactosialidosis (GS) is a rare lysosomal storage disorder. We reported here, the case of a 29-day-old boy who had increased body swelling, difficulty breathing, and petechiae on the trunk since birth. The antenatal history was unremarkable. Clinical laboratory findings included coarse facies, hepatosplenomegaly, gross ascites, thrombocytopenia, nephrotic range proteinuria, and bilateral hydronephrosis. The diagnostic challenge was resolved after genetic testing, which revealed GS with a novel homozygous c.1158dupA mutation.