Fabry disease is a lysosomal disorder whose causes are mutations inthe GLA gene, mapped in the human X chromosome (Xq22). Suchmutations result either in the incapacity of the enzyme entering thelysosome or the reduction/elimination of the activity of the α-galactosidase A (α-GAL) enzyme, whose function is to metabolizeintralysosomal glycosphingolipids, e.g. globotriaosylceramide (Gb3), themajor lipid accumulated in the lysosomes in FD. The appearance of renaldisease in these patients is among the consequences of the accumulationof Gb3. Recent studies show that podocyte is the most affected renal cellin the disease and whose response is the most difficult to the enzymereplacement therapy. On the other hand, it is the cell responsible fortheprogressive loss of the renal function and is found altered even beforewe have microalbuminuria. As physiologically there is excretion ofpodocytes in the urine, determining the podocyturia in FD is aninteresting element to predict renal disease. The objective of our studywas to quantify the excretion of urinary podocytes in FD patients with aclassic Fabry genotype (V269M, n= 13) with eGFR range from normalto reduced andhealthy controls (n = 40), and to correlate themwith thevariables gender, age treatment time and albumin:creatinine ratio(ACR). Fresh urine sampled immediately after first urination in themorning was used. Urinary podocytes were stained using an immuno-fluorescence technique to podocalyxin andDAPi on laminas. The numberof podocalyxin-positive cells was counted by two medical techniciansand the mean of the number was taken (normal range 0-0.8 podocytes/mL). From the 14 samples analyzed, 7 came from males and 7 fromfemales, the age ranged from 8-74 years and the treatment time withalgasidase alpha from 0-24 months. The mean of podocytes in urine ofFD patients was significantly higher than in healthy controls(p b 0.0001). The correlation podocyturia/ACR was positive and statis-tically significant (p = 0.004). There was no correlation of podocyturiawith gender, age and time of treatment. Podocyturia is an importantparameter in the assessment of renal disease in general, and itmay serveas an additional early laboratory examination for monitoring FDnephropaty before altered ACRmodifying, thereafter, the natural historyof the disease in patients expected to have amore aggressive phenotype.This work was supported by a grant from Shire.

doi:10.1016/j.ymgme.2013.12.206

195Mutations and polymorphisms of the alpha-galactosidase A genein patients with hypertrophic cardiomyopathy

Stefan Pfaffenberger, Natalija Lajic, Martina Gaggl, Anita Jallitsch-Halper, Sabine Scherzer, Jolanta Siller-Matula, Raphael Rosenhek, TillVoigtlaender, Raute Sunder-Plassmann, Gere Sunder-Plassmann,Gerald Mundigler, Medical University Vienna, Vienna, Austria

Background: Anderson-Fabry disease (AFD) is a rare cause ofhypertrophic cardiomyopathies (HCM). Clinical signs alone do not allowdistinguishing a cardiac manifestation of AFD from sarcomeric forms ofHCM. Enzyme activity analysis and genetic testing of theα-galactosidaseA (α-GAL) gene (GLA) are therefore important for diagnosis andverification of disease causing mutations.

Design: Prospective cross-sectional single centre study.Patients: We enrolled 108 adults (76 males, 32 females) with a

referral diagnosis of HCM with a left ventricular wall thickness of≥15 mm on echocardiography. Main outcome measures Laboratoryanalyses included the measurement of α-GAL activity in leukocytesand sequencing of the GLA gene in all patients. Symptoms wereevaluated using a specified questionnaire.

Results: Mutation analyses confirmed AFD in two patients (p.G35Rand g.5092A N G; 1.9%). One female patient (0.98%) had a rarepolymorphism (p.D313Y) previously described as disease causing for

AFD. In 31 patients (28.7%) various combinations of polymorphismswere detected. The g.1170C N T polymorphism was found in 9 patients(7 males) and was associated with a significantly decreased α-GALactivity in leukocytes among male subjects compared to the wild typeGLA gene (p = 0.003). Clinically these patients showed higher frequen-cies of non-sustained ventricular tachycardias (nsVTs, p = 0.009).

Conclusions: Specific testing of the GLA gene in patients with HCMconfirmed AFD in two patients and revealed various polymorphismsin almost one third of patients. The g.1170C N T polymorphism wasfound in 8% and is associated with a reduced α-GAL activity and ahigher incidence of nsVTs in males.

doi:10.1016/j.ymgme.2013.12.207

196Hereditary spastic paraplegias types 15 and 11 are associated withlysosomal abnormalities

Tyler Mark Piersona, Benoît Renvoiséb, Jaerak Changb, Camilo Toroc,Craig Blackstoneb, aCedars-Sinai Medical Center, Los Angeles, CA, USA,bNINDS/NIH, Bethesda, MD, USA, cNHGRI/NIH, Bethesda, MD, USA

The hereditary spastic paraplegias (HSP) are among the mostgenetically diverse inherited neurological disorders with over 50 distinctdisease loci identified to date. The identification of cellular themescommon among the HSP is important for understanding diseasepathogenesis. SPG15 involves mutations in SPG15 (aka ZFYVE26)encoding spastizin (aka FYVE-CENT),while SPG11 is caused bymutationsin the SPG11 gene affecting the spatacsin protein. We investigatedSPG15-related cellular changes in patient fibroblasts, seeking to identifyshared pathogenic themes between SPG15 and SPG11. These twoclinically-similar disorders are the most common autosomal recessiveforms of HSP, and are characterized clinically by progressive spasticparaplegia along with a thin corpus callosum, white matter abnormal-ities, progressive cognitive impairment, lenticular opacities, and retinalstorage. Furthermore, both have been linked to early-onset Parkinsonism.Fibroblast cell lines prepared from different patients with SPG15had selective enlargement of lysosomal size and consistently showedabnormal lysosomal storage by electron microscopy. Lysosomal enlarge-ment was also observed in cell lines from multiple patients with SPG11,though prominent abnormal lysosomal storage was not observed. Thestability of the SPG15 protein, spastizin, and the SPG11 protein, spatacsin,were highly dependent upon one another's presence. Emerging studiesimplicating these two proteins in interactions with the late endosomal/lysosomal adaptor protein complex AP-5 are consistentwith their similarabnormalities in the sizes of lysosomes suggesting a convergingmechanism for these two disorders involving the lysosome.

doi:10.1016/j.ymgme.2013.12.208

197TNF-α levels are increased in children with mucopolysaccharidosistypes I, II, and VI treated with ERT

Lynda E. Polgreen, Richard Vehe, Kyle Rudser, Alicia Kunin-Batson,Jeanine Utz, Elsa Shapiro, Chester B. Whitley, University of Minnesota,Minneapolis, MN, USA

Despite treatment with enzyme replacement therapy (ERT), themajority of individuals with mucopolysaccharidosis (MPS) type I, II or VIreport significant decreased physical function andpain. In animalmodelsof MPS, tumor necrosis factor - alpha (TNF-α) levels are increased andtreatment with TNF-α inhibitors improve physical function. Therefore,

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