Beta Thalassemia Major with Gaucher's Disease: A Rare Entity

Thalassemia is a genetic disorder due to deletion or mutation in the gene for alpha or beta chain of hemoglobin. Gaucher's disease (GD) is characterized by a deficiency of a lysosomal enzyme, glucocerebrosidase which occurs due to mutations in the GBA1 gene on chromosome 1. Thalassemia and GD have overlapping clinical manifestations and present with features such as anemia, hepatosplenomegaly, and skeletal involvement. This creates a diagnostic conundrum for physicians. We present a case of an 11-month-old female who presented with fever, increasing paleness, and labored breathing. She had a recent history of uncross-matched transfusion. The child showed signs of anemic failure. Physical exam findings strongly pointed towards hemolytic anemia due to thalassemia major. Genetic analysis confirmed homozygosity in Fr 8-9 mutation confirming beta thalassemia major. Bicytopenia along with visceromegaly indicated malaria or storage diseases. Enzyme analysis revealed low levels of beta-glucocerebrosidase with normal acid sphingomyelinase levels confirming GD. In our case, we report the association of beta thalassemia major with GD which is a rare entity. The report highlights the need for an independent assessment of disorders that have similar presentations to avoid missing an associated disorder.

The glucocerobrosidase E326K variant predisposes to Parkinson's disease, but does not cause Gaucher's disease

BACKGROUND

Heterozygous loss-of-function mutations in the acid beta-glucocerebrosidase (GBA1) gene, responsible for the recessive lysosomal storage disorder, Gaucher's disease (GD), are the strongest known risk factor for Parkinson's disease (PD). Our aim was to assess the contribution of GBA1 mutations in a series of early-onset PD.

METHODS

One hundred and eighty-five PD patients (with an onset age of ≤50) and 283 age-matched controls were screened for GBA1 mutations by Sanger sequencing.

RESULTS

We show that the frequency of GBA1 mutations is much higher in this patient series than in typical late-onset patient cohorts. Furthermore, our results reveal that the most prevalent PD-associated GBA1 mutation is E326K, a variant that does not, when homozygous, cause GD.

CONCLUSIONS

Our results confirm recent reports that the mutation, E326K, predisposes to PD and suggest that, in addition to reduced GBA1 activity, other molecular mechanisms may contribute to the development of the disease.

Gaucher's disease and cancer: a sphingolipid perspective

Gaucher's disease is a sphingolipidosis characterized by a specific deficiency in an acidic glucocerebrosidase, which results in aberrant accumulation of glucosylceramide primarily within the lysosome. Gaucher's disease has been correlated with cases of myeloma, leukemia, glioblastoma, lung cancer, and hepatocellular carcinoma, although the reasons for the correlation are currently being debated. Some suggest that the effects of Gaucher's disease may be linked to cancer, while others implicate the therapies used to treat Gaucher's disease. This debate is not entirely surprising, as the speculations linking Gaucher's disease with cancer fail to address the roles of ceramide and glucosylceramide in cancer biology. In this review, we will discuss, in the context of cancer biology, ceramide metabolism to glucosylceramide, the roles of glucosylceramide in multidrug-resistance, and the role of ceramide as an anticancer lipid. This review should reveal that it is most practical to associate elevated glucosylceramide, which accompanies Gaucher's disease, with the progression of cancer. Furthermore, this review proposes that the therapies used to treat Gaucher's disease, which augment ceramide accumulation, are likely not linked to correlations with cancer.

1-Deoxynojirimycins with dansyl capped N-substituents as probes for Morbus Gaucher affected cell lines

Cyclization by double reductive amination of d-xylo-hexos-5-ulose with methyl 6-aminohexanoate gave (methoxycarbonyl)pentyl-1-deoxynojirimycin. Reaction of the terminal carboxylic acid with N-dansyl-1,6-diaminohexane provided the corresponding chain-extended fluorescent derivative. By reaction with bis(6-dansylaminohexyl)amine, the corresponding branched di-N-dansyl compound was obtained. Both compounds are strong inhibitors of d-glucosidases and could also be shown to distinctly improve, at sub-inhibitory concentrations, the activity of beta-glucocerebrosidase in a Gaucher fibroblast (N370S) cell-line through chaperoning of the enzyme to the lysosome.

Detection of ligand binding hot spots on protein surfaces via fragment-based methods: application to DJ-1 and glucocerebrosidase

The identification of hot spots, i.e., binding regions that contribute substantially to the free energy of ligand binding, is a critical step for structure-based drug design. Here we present the application of two fragment-based methods to the detection of hot spots for DJ-1 and glucocerebrosidase (GCase), targets for the development of therapeutics for Parkinson's and Gaucher's diseases, respectively. While the structures of these two proteins are known, binding information is lacking. In this study we employ the experimental multiple solvent crystal structures (MSCS) method and computational fragment mapping (FTMap) to identify regions suitable for the development of pharmacological chaperones for DJ-1 and GCase. Comparison of data derived via MSCS and FTMap also shows that FTMap, a computational method for the identification of fragment binding hot spots, is an accurate and robust alternative to the performance of expensive and difficult crystallographic experiments.