N association of D313Y with other typical FD manifestations, e.g. 15900046 peripheral neuropathy, hypertrophic cardiomyopathy, renal buy Lecirelin failure, or stroke [21?5]. However, most authors considered the D313Y mutation as non-causal. Thus, as a consequence, to date almost all D313Ycarriers are not treated with ERT [10]. Other studies support our results and found also primarily neurological organ manifestations in patients carrying GLA D313Y. In this respect, a recent prospective study including 625 patients with cerebral ischemia aged between 18 and 55 reported that GLA D313Y was associated with cryptogenic stroke [25]. Recent reports point to an association of particular mutations with a” late-onset” or “intermediate” type of FD, e.g. N215S, A143T or F113C [26?8]. In this regard, the authors concluded that mutations that were formerly assumed as non-causal but nonetheless showed variable FD symptoms might be considered as “predisposing polymorphisms” (e.g. R118C or E66Q). In view of the above mentioned studies, this could particularly be the case with the D313Y mutation causing a CNS involvement. It should, however, be noted that our findings could still represent a clinical coincidence. Thus, further studies are necessary to confirm a causal relationship between the D313Y mutation and cerebral manifestations.White Matter Lesions Due to GLA D313YFigure 4. MR images of family members that were negative for D313Y did not show any white matter changes. Upper row: Sagittal FLAIR-sequence; median and lower row: Axial T2-weighted sequences of subject III.16 and III.17. doi:10.1371/journal.pone.0055565.gThe significant difference of enzymatic 68181-17-9 web activity in leukocytes and plasma caused by the change of aspartic acid to threonine at position 313 is most likely due to a functional intolerance to blood plasma neutral pH conditions. This obviously results in a profounddecrease of enzymatic GLA activity in plasma [9]. Additionally, this effect seems to be irreversible. Once in contact with a neutral or basic pH environment D313Y remains inactive, even if transferred to optimal pH (unpublished data). The GLA substrateWhite Matter Lesions Due to GLA D313YTable 2. Summary of investigated parameters and abnormalities as typical for FD.Laboratory FD parameters Enzyme activity in CDS Age mutation 71 74 76 58 38 49 34 41 25 31 D313Y D313Y D313Y D313Y D313Y D313Y D313Y D313Y no no Plasma [nmol MU/h/ml] 2.39 5.67 0.60 3.21 4.89 5.83 n.d. 0.10 9.14 10.1 Leukocytes [nmol MU/h/mg] 78 83 161 38 55 n.d n.d. 79 57 64 Lyso-Gb3 [ng/ml] 0.83 0.41 0.82 0.61 1.26 n.d. 1.82 0.75 n.d. n.d. GLA RNA expression yes yes yes yes n.d. yes n.d. yes yes yes GLA expression in plasma yes yes yes yes yes yes n.d. yes yes yesFD typical abnormalitiesPatient Sex II.3 II.4 II.6 II.7 III.7 III.8 III.11 III.14 III.16 III.17 m f f f f f f f f fRenal Cardiac no no no no no no no no no no no no no no no no no no no noNeurologic WML WML WML WML n.d. WML WML WML no NoRenal parameters: ultrasonography, albumin/creatinine ratio, determination of eGFR. Cardiac parameters: echocardiography, cardiac magnetic resonance imaging (MRI) and electrocardiogram. Neural/cerebral parameters: MRI, neurography and neuropsychologic diagnostics. Reference values: plasma activity .8.0 nmol MU/h/ml; leukocyte activity .33 nmol MU/h/mg protein; lyso-Gb3,1.84 ng/ml. n.d.: not determined; WML: white matter lesions. Abnormal findings are highlighted in bold. doi:10.1371/journal.pone.0055565.tGb3, also known as CD77, has been s.N association of D313Y with other typical FD manifestations, e.g. 15900046 peripheral neuropathy, hypertrophic cardiomyopathy, renal failure, or stroke [21?5]. However, most authors considered the D313Y mutation as non-causal. Thus, as a consequence, to date almost all D313Ycarriers are not treated with ERT [10]. Other studies support our results and found also primarily neurological organ manifestations in patients carrying GLA D313Y. In this respect, a recent prospective study including 625 patients with cerebral ischemia aged between 18 and 55 reported that GLA D313Y was associated with cryptogenic stroke [25]. Recent reports point to an association of particular mutations with a” late-onset” or “intermediate” type of FD, e.g. N215S, A143T or F113C [26?8]. In this regard, the authors concluded that mutations that were formerly assumed as non-causal but nonetheless showed variable FD symptoms might be considered as “predisposing polymorphisms” (e.g. R118C or E66Q). In view of the above mentioned studies, this could particularly be the case with the D313Y mutation causing a CNS involvement. It should, however, be noted that our findings could still represent a clinical coincidence. Thus, further studies are necessary to confirm a causal relationship between the D313Y mutation and cerebral manifestations.White Matter Lesions Due to GLA D313YFigure 4. MR images of family members that were negative for D313Y did not show any white matter changes. Upper row: Sagittal FLAIR-sequence; median and lower row: Axial T2-weighted sequences of subject III.16 and III.17. doi:10.1371/journal.pone.0055565.gThe significant difference of enzymatic activity in leukocytes and plasma caused by the change of aspartic acid to threonine at position 313 is most likely due to a functional intolerance to blood plasma neutral pH conditions. This obviously results in a profounddecrease of enzymatic GLA activity in plasma [9]. Additionally, this effect seems to be irreversible. Once in contact with a neutral or basic pH environment D313Y remains inactive, even if transferred to optimal pH (unpublished data). The GLA substrateWhite Matter Lesions Due to GLA D313YTable 2. Summary of investigated parameters and abnormalities as typical for FD.Laboratory FD parameters Enzyme activity in CDS Age mutation 71 74 76 58 38 49 34 41 25 31 D313Y D313Y D313Y D313Y D313Y D313Y D313Y D313Y no no Plasma [nmol MU/h/ml] 2.39 5.67 0.60 3.21 4.89 5.83 n.d. 0.10 9.14 10.1 Leukocytes [nmol MU/h/mg] 78 83 161 38 55 n.d n.d. 79 57 64 Lyso-Gb3 [ng/ml] 0.83 0.41 0.82 0.61 1.26 n.d. 1.82 0.75 n.d. n.d. GLA RNA expression yes yes yes yes n.d. yes n.d. yes yes yes GLA expression in plasma yes yes yes yes yes yes n.d. yes yes yesFD typical abnormalitiesPatient Sex II.3 II.4 II.6 II.7 III.7 III.8 III.11 III.14 III.16 III.17 m f f f f f f f f fRenal Cardiac no no no no no no no no no no no no no no no no no no no noNeurologic WML WML WML WML n.d. WML WML WML no NoRenal parameters: ultrasonography, albumin/creatinine ratio, determination of eGFR. Cardiac parameters: echocardiography, cardiac magnetic resonance imaging (MRI) and electrocardiogram. Neural/cerebral parameters: MRI, neurography and neuropsychologic diagnostics. Reference values: plasma activity .8.0 nmol MU/h/ml; leukocyte activity .33 nmol MU/h/mg protein; lyso-Gb3,1.84 ng/ml. n.d.: not determined; WML: white matter lesions. Abnormal findings are highlighted in bold. doi:10.1371/journal.pone.0055565.tGb3, also known as CD77, has been s.