BackgroundGaucher disease (GD) is a genetic disease caused by mutations in the GBA1 gene which result in reduced enzymatic activity of β-glucocerebrosidase (GCase). This study identified the progranulin (PGRN) gene (GRN) as another gene associated with GD.MethodsSerum levels of PGRN were measured from 115 GD patients and 99 healthy controls, whole GRN gene from 40 GD patients was sequenced, and the genotyping of 4 SNPs identified in GD patients was performed in 161 GD and 142 healthy control samples. Development of GD in PGRN-deficient mice was characterized, and the therapeutic effect of rPGRN on GD analyzed.FindingsSerum PGRN levels were significantly lower in GD patients (96.65 ± 53.45 ng/ml) than those in healthy controls of the general population (164.99 ± 43.16 ng/ml, p < 0.0001) and of Ashkenazi Jews (150.64 ± 33.99 ng/ml, p < 0.0001). Four GRN gene SNPs, including rs4792937, rs78403836, rs850713, and rs5848, and three point mutations, were identified in a full-length GRN gene sequencing in 40 GD patients. Large scale SNP genotyping in 161 GD and 142 healthy controls was conducted and the four SNP sites have significantly higher frequency in GD patients. In addition, “aged” and challenged adult PGRN null mice develop GD-like phenotypes, including typical Gaucher-like cells in lung, spleen, and bone marrow. Moreover, lysosomes in PGRN KO mice exhibit a tubular-like appearance. PGRN is required for the lysosomal appearance of GCase and its deficiency leads to GCase accumulation in the cytoplasm. More importantly, recombinant PGRN is therapeutic in various animal models of GD and human fibroblasts from GD patients.InterpretationOur data demonstrates an unknown association between PGRN and GD and identifies PGRN as an essential factor for GCase's lysosomal localization. These findings not only provide new insight into the pathogenesis of GD, but may also have implications for diagnosis and alternative targeted therapies for GD.

ObjectiveVariants in GBA are associated with Lewy Body (LB) pathology. We investigated whether variants in other lysosomal storage disorder (LSD) genes also contribute to disease pathogenesis.MethodsWe performed a genetic analysis of four LSD genes including GBA, HEXA, SMPD1, and MCOLN1 in 231 brain autopsies. Brain autopsies included neuropathologically defined LBD without Alzheimer Disease (AD) changes (n = 59), AD without significant LB pathology (n = 71), Alzheimer disease and lewy body variant (ADLBV) (n = 68), and control brains without LB or AD neuropathology (n = 33). Sequencing of HEXA, SMPD1, MCOLN1 and GBA followed by ‘gene wise’ genetic association analysis was performed. To determine the functional effect, a biochemical analysis of GBA in a subset of brains was also performed. GCase activity was measured in a subset of brain samples (n = 64) that included LBD brains, with or without GBA mutations, and control brains. A lipidomic analysis was also performed in brain autopsies (n = 67) which included LBD (n = 34), ADLBV (n = 3), AD (n = 4), PD (n = 9) and control brains (n = 17), comparing GBA mutation carriers to non-carriers.ResultsIn a ‘gene-wise’ analysis, variants in GBA, SMPD1 and MCOLN1 were significantly associated with LB pathology (p range: 0.03–4.14 x10-5). Overall, the mean levels of GCase activity were significantly lower in GBA mutation carriers compared to non-carriers (p<0.001). A significant increase and accumulation of several species for the lipid classes, ceramides and sphingolipids, was observed in LBD brains carrying GBA mutations compared to controls (p range: p<0.05-p<0.01).InterpretationOur study indicates that variants in GBA, SMPD1 and MCOLN1 are associated with LB pathology. Biochemical data comparing GBA mutation carrier to non-carriers support these findings, which have important implications for biomarker development and therapeutic strategies.

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Canavan disease, an inherited leukodystrophy, is caused by mutations in the aspartoacylase (ASPA) gene. It is most common among children of Ashkenazi Jewish descent but has been diagnosed in many diverse ethnic groups. Two mutations comprise the majority of mutant alleles in Jewish patients, while mutations in the ASPA gene among non-Jewish patients are different and more diverse. In the present study, the ASPA gene was analysed in 22 unrelated non-Jewish patients with Canavan disease, and 24 different mutations werefound.Ofthese,14arenovel,including¢vemissensemutations(E24G,D68A, D249V, C152W, H244R), two nonsense mutations (Q184X, E214X), three deletions (923delT, 33del13, 244delA), one insertion mutation (698insC), two sequence variations in one allele ([10T>G; 11insG]), an elimination of the stop codon (941A>G, TAG!TGG, X314W), and one splice acceptor site mutation (IVS1 À 2A>T). The E24G mutation resulted in substitution of an invariable amino acid residue (Glu) in the ¢rst esterase catalytic domain consensus sequence. The IVS1 À 2A>T mutation caused the retention of 40 nucleotides of intron 1 upstream of exon 2. The results of transient expression of the mutant ASPA cDNA containing these mutations in COS-7 cells and assays for ASPA activity of patient ¢broblasts indicated that these mutations were responsible for the enzyme de¢ciency. In addition, patients with the novel D249V mutation manifested clinically at birth and died early. Also, patients with certain other novel mutations, includingC152W,E214X,X314W,andframeshiftmutationsinbothalleles,developed clinical manifestations at an earlier age than in classical Canavan disease.

We describe two sisters with a mild-onset variant of Canavan's disease who presented at age 50 and 19 months with developmental delay but without macrocephaly, hypotonia, spasticity, or seizures. Remarkably, both patients had age-appropriate head control, gross motor development, and muscle tone. There were very mild deficits in fine motor skills, coordination, and gait. Both sisters had a history of strabismus, but otherwise vision was normal. The older child showed evidence of mild cognitive and social impairment, whereas language and behavior were normal for age in the infant. Both patients were found to be compound heterozygotes for C914A (A305E) and G212A (R71H) mutations in ASPA. Like all other known ASPA mutations, this previously unknown G212A mutation appears to have low absolute enzyme activity. Nevertheless, it is associated in these patients with an extremely benign phenotype that is highly atypical of Canavan's disease. Biochemical and clinical data were evaluated using a generalized linear mixed model generated from 25 other subjects with Canavan's disease. There were statistically significant differences in brain chemistry and clinical evaluations, supporting a distinct variant of Canavan's disease. Future studies of ASPA enzyme structure and gene regulation in these subjects could lead to a better understanding of Canavan's pathophysiology and improvements in ASPA gene therapy.