Cystinosis

Cystinuria and cystinosis are usually related to L-cystine: is this really the case for cystinosis? A physicochemical investigation at micrometre and nanometre scale

“…The physicochemistry of cystinosis seems to be quite inconsistent. The literature clearly indicates the presence of rectangular crystals made of cystine [29][30][31][71][72][73][74][75][76][77][78][79]81]. Such morphology is not expected for cystine crystals which are typically hexagonal for synthetic [47][48][49][50][51][52][53][54] as well as for biological [18][19][20][21]24,55,56,[64][65][66] samples.…”

“…The cystinosis situation is quite different from cystinuria. An analysis of the literature [29][30][31]71,72] indicates that cystine is the only compound represented in the abnormal deposits and that such crystals (Figures 5 and 6) do not exhibit a hexagonal morphology. Optical microscopy in contrast shows a rectangular crystal morphology in both the kidney (Fig- ure 5a, according to Nesterova et al [29]) and the cornea (Figure 5b, according to Elmonem et al [71]).…”

“…A small number of publications have reported physicochemical investigation of abnormal deposits in these tissues. Frazier and Wong [30] have characterised the rectangular extracellular crystalline forms observed in ocular tissue in two childhood and two adult cases by X-ray diffraction (XRD), leading to the identification of cystine crystals. More recently, Centeno et al [31] have confirmed this chemical composition based on Raman spectroscopy analysis of abnormal deposits present in liver and spleen.…”