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High-risk screening trial of Gaucher disease for patients with neurological symptoms
Abstracts / Molecular Genetics and Metabolism 120 (2016) S17–S145
volume/PC [V(Inc/PC)] (r =-0.69, p = 0.0001), but not with GL-3 volume fraction [Vv(Inc/PC)] or foot process width (FPW). Using piecewise linear regression analysis, 88% of Nv(PC/glom) variability was explained by VPC and V(Inc/PC), p = 0.000001, with the V(Inc/PC) breakpoint at 1965 um3 . While patients with V(Inc/PC) b 1965 um3 did not show any relationship between Nv(PC/glom) and age, or V(Inc/PC) and UPCR; for those with V(Inc/PC) N 1965 um3, Nv(PC/glom) declined with age (r =-0.61, p = 0.03) and V(Inc/PC) strongly correlated with UPCR (r = 0.74, p = 0.004). Patients with V(Inc/PC) b 1965 um3 were younger, had smaller podocytes, greater Nv(PC/glom) and a trend towards lesser UPCR compared to those with V(Inc/PC) b 1965 um3. Conclusion: Podocytes enlargement and total GL-3 accumulation are important determinants of podocytes loss in Fabry disease. The observed V(Inc/PC) breakpoint suggest a threshold beyond which podocytes GL-3 accumulation leads to progressive podocytes loss with age and proteinuria. Such threshold may potentially be used as a treatment target for Fabry nephropathy.
doi:10.1016/j.ymgme.2016.11.252
244 High-risk screening trial of Gaucher disease for patients with neurological symptoms Kimitoshi Nakamura, Ken Momosaki, Shinichiro Yoshida, Fumio Endo, Kumamoto University, Kumamoto, Japan Gaucher disease is a lysosome disease, characterized by accumulation of the substrate glucocerebroside in reticuloendothelial cells due to reduced enzyme activity of glucocerebrosidase. Gaucher disease is classified into 3 types: type 1 with a chief complaint of splenohepatomegaly, anemia, and bone symptoms; type 2 with rapidly progressing neurological symptoms; and type 3 with slowly progressing myoclonus, abnormal eye movement and other symptoms. Recently, enzyme replacement therapy has become available, prompting establishment of early treatment of Gaucher disease. This has increased the importance of early diagnosis using clinical symptoms as clue. The objective of this study is to develop effective screening method and verify the system in order to establish screening for Gaucher disease with enzyme assay among patients with early-onset seizures. After obtaining informed consent from subjects, screening test for Gaucher disease was conducted at medical institutions. The study population consisted of patients with early-onset seizures. Blood will be sampled on filter paper and sent to the Department of Pediatrics, Kumamoto University Hospital to measure glucocerebrosidase activity. If measurement detects abnormally low enzyme activity, suggestive of Gaucher disease, in a patient, the patient was examined for splenohepatomegaly, neurological symptoms, or bone symptoms and undergo bone marrow test as well as blood acid phosphatase (ACP) and angiotensin-converting enzyme (ACE) measurement at the medical institution. Glucocerebrosidase genetic analysis was also be performed with separate consent from the patient. Based on our study, we found one neurological type Gaucher patient with seizure, collodion skin and hepatosplenomegaly. An efficient diagnostic system for high-risk patients could be established to develop an algorithm for early diagnosis and treatment of Gaucher disease.
doi:10.1016/j.ymgme.2016.11.253
S101
245 14 novel mutations of GLA gene as a result of selective Fabry disease screening in Russian Federation Leyla Namazova-Baranova, Kirill Savostyanov, Alexey Sukhozhenko, Alexander Pushkov, Nataliya Mazanova, Alexander Pakhomov, Alexander Baranov, FSAI Scientific Center of Children's Health, Moscow, Russian Federation Fabry disease is a rare X-linked inherited disorder that results from the buildup of a particular type of fat, called globotriaosylceramide, in the body's cells. Fabry disease is caused by mutations in the GLA gene, encoding alpha-galactosidase A. We investigated more than 9000 patients for the period of 18 months from more than 20 regions aged from 14 to 67 years with renal failure disease and early stroke. Alpha-galactosidase A activity and lyso-Gb3 concentration was measured in DBS using MS/MS. For mutations detection, each exon with flanking intronic sequences was sequenced. We found 32 patients from 29 families with reduced alpha-galactosidase A activity and GLA gene mutations, while 14 mutations was novel. Ten novel missense mutations: c.166TNA, c.187TNC, c.521GNA, c.818TNC, c.847CNA, c.889TNC, c.902GNT, c.981ANC, c.1163TNA, c.1211GNA, three novel small deletions: c.834del, c.1085_1098del, c.1121_1123del, and one novel splicing mutation c.548-2ANG. The silico analysis together with the lyso-Gb3 level were useful methods to prove the pathogenicity of previously undescribed mutations in GLA gene. Lyso-Gb3 level was not increased in patients with nucleotide substitution c.427GNA and c.376A NG, which have conflicting interpretation of pathogenicity according literature. The highest level of lyso-Gb3 and lowest of alpha-galactosidase A activity was indicated in patients with nonsense mutations and deletions. For females carriers of GLA mutations the range of lyso-Gb3 concentration was significantly higher instead of alpha-galactosidase A activity, that which in most cases was around cut-off levels. The incidence of Fabry disease in high-risk groups was estimated around 3,6 in 1,000 while the frequency of novel mutations was 48,3% among undocumented earlier unrelated patients may indicate insufficient examination patients inhabiting the territory of Russia. The DBS lyso-Gb3 level was consistent with the phenotype of Fabry disease, reflected the severity of the disease and may be an additional criterion for the start of enzyme replacement therapy.
doi:10.1016/j.ymgme.2016.11.254
246 Multiple lysosomal diseases - newborn screening in a Mexican cohort of patients Juana I Navarrete, Hospital Central Sur PEMEX, Mexico City, Mexico Lysosomal diseases are a diverse group of over 50 inherited metabolic disorders, that result in cellular disfunction and multiple organ damage due to a progressive accumulation of metabolic precursors within the lysosomes, secondary to reduced or lack of a lysosomal enzyme. The prevalence of these conditions had revealed unexpected higher frequencies of lysosomal diseases. Petroleos Mexicanos is a big governmental institution with approximately ten thousand workers and their families. Since 2005 a larger screening test has been done to all newborns in this institution through all the country. We test for most aminoacidopathies including acidurias, hemoglobinopathies, G6PD deficiency, adrenal hyperplasia, cystic fibrosis and biotinidase deficiency. Since August 2012 we included in ou newborn screening program one immunodeficiency and six
volume/PC [V(Inc/PC)] (r =-0.69, p = 0.0001), but not with GL-3 volume fraction [Vv(Inc/PC)] or foot process width (FPW). Using piecewise linear regression analysis, 88% of Nv(PC/glom) variability was explained by VPC and V(Inc/PC), p = 0.000001, with the V(Inc/PC) breakpoint at 1965 um3 . While patients with V(Inc/PC) b 1965 um3 did not show any relationship between Nv(PC/glom) and age, or V(Inc/PC) and UPCR; for those with V(Inc/PC) N 1965 um3, Nv(PC/glom) declined with age (r =-0.61, p = 0.03) and V(Inc/PC) strongly correlated with UPCR (r = 0.74, p = 0.004). Patients with V(Inc/PC) b 1965 um3 were younger, had smaller podocytes, greater Nv(PC/glom) and a trend towards lesser UPCR compared to those with V(Inc/PC) b 1965 um3. Conclusion: Podocytes enlargement and total GL-3 accumulation are important determinants of podocytes loss in Fabry disease. The observed V(Inc/PC) breakpoint suggest a threshold beyond which podocytes GL-3 accumulation leads to progressive podocytes loss with age and proteinuria. Such threshold may potentially be used as a treatment target for Fabry nephropathy.
doi:10.1016/j.ymgme.2016.11.252
244 High-risk screening trial of Gaucher disease for patients with neurological symptoms Kimitoshi Nakamura, Ken Momosaki, Shinichiro Yoshida, Fumio Endo, Kumamoto University, Kumamoto, Japan Gaucher disease is a lysosome disease, characterized by accumulation of the substrate glucocerebroside in reticuloendothelial cells due to reduced enzyme activity of glucocerebrosidase. Gaucher disease is classified into 3 types: type 1 with a chief complaint of splenohepatomegaly, anemia, and bone symptoms; type 2 with rapidly progressing neurological symptoms; and type 3 with slowly progressing myoclonus, abnormal eye movement and other symptoms. Recently, enzyme replacement therapy has become available, prompting establishment of early treatment of Gaucher disease. This has increased the importance of early diagnosis using clinical symptoms as clue. The objective of this study is to develop effective screening method and verify the system in order to establish screening for Gaucher disease with enzyme assay among patients with early-onset seizures. After obtaining informed consent from subjects, screening test for Gaucher disease was conducted at medical institutions. The study population consisted of patients with early-onset seizures. Blood will be sampled on filter paper and sent to the Department of Pediatrics, Kumamoto University Hospital to measure glucocerebrosidase activity. If measurement detects abnormally low enzyme activity, suggestive of Gaucher disease, in a patient, the patient was examined for splenohepatomegaly, neurological symptoms, or bone symptoms and undergo bone marrow test as well as blood acid phosphatase (ACP) and angiotensin-converting enzyme (ACE) measurement at the medical institution. Glucocerebrosidase genetic analysis was also be performed with separate consent from the patient. Based on our study, we found one neurological type Gaucher patient with seizure, collodion skin and hepatosplenomegaly. An efficient diagnostic system for high-risk patients could be established to develop an algorithm for early diagnosis and treatment of Gaucher disease.
doi:10.1016/j.ymgme.2016.11.253
S101
245 14 novel mutations of GLA gene as a result of selective Fabry disease screening in Russian Federation Leyla Namazova-Baranova, Kirill Savostyanov, Alexey Sukhozhenko, Alexander Pushkov, Nataliya Mazanova, Alexander Pakhomov, Alexander Baranov, FSAI Scientific Center of Children's Health, Moscow, Russian Federation Fabry disease is a rare X-linked inherited disorder that results from the buildup of a particular type of fat, called globotriaosylceramide, in the body's cells. Fabry disease is caused by mutations in the GLA gene, encoding alpha-galactosidase A. We investigated more than 9000 patients for the period of 18 months from more than 20 regions aged from 14 to 67 years with renal failure disease and early stroke. Alpha-galactosidase A activity and lyso-Gb3 concentration was measured in DBS using MS/MS. For mutations detection, each exon with flanking intronic sequences was sequenced. We found 32 patients from 29 families with reduced alpha-galactosidase A activity and GLA gene mutations, while 14 mutations was novel. Ten novel missense mutations: c.166TNA, c.187TNC, c.521GNA, c.818TNC, c.847CNA, c.889TNC, c.902GNT, c.981ANC, c.1163TNA, c.1211GNA, three novel small deletions: c.834del, c.1085_1098del, c.1121_1123del, and one novel splicing mutation c.548-2ANG. The silico analysis together with the lyso-Gb3 level were useful methods to prove the pathogenicity of previously undescribed mutations in GLA gene. Lyso-Gb3 level was not increased in patients with nucleotide substitution c.427GNA and c.376A NG, which have conflicting interpretation of pathogenicity according literature. The highest level of lyso-Gb3 and lowest of alpha-galactosidase A activity was indicated in patients with nonsense mutations and deletions. For females carriers of GLA mutations the range of lyso-Gb3 concentration was significantly higher instead of alpha-galactosidase A activity, that which in most cases was around cut-off levels. The incidence of Fabry disease in high-risk groups was estimated around 3,6 in 1,000 while the frequency of novel mutations was 48,3% among undocumented earlier unrelated patients may indicate insufficient examination patients inhabiting the territory of Russia. The DBS lyso-Gb3 level was consistent with the phenotype of Fabry disease, reflected the severity of the disease and may be an additional criterion for the start of enzyme replacement therapy.
doi:10.1016/j.ymgme.2016.11.254
246 Multiple lysosomal diseases - newborn screening in a Mexican cohort of patients Juana I Navarrete, Hospital Central Sur PEMEX, Mexico City, Mexico Lysosomal diseases are a diverse group of over 50 inherited metabolic disorders, that result in cellular disfunction and multiple organ damage due to a progressive accumulation of metabolic precursors within the lysosomes, secondary to reduced or lack of a lysosomal enzyme. The prevalence of these conditions had revealed unexpected higher frequencies of lysosomal diseases. Petroleos Mexicanos is a big governmental institution with approximately ten thousand workers and their families. Since 2005 a larger screening test has been done to all newborns in this institution through all the country. We test for most aminoacidopathies including acidurias, hemoglobinopathies, G6PD deficiency, adrenal hyperplasia, cystic fibrosis and biotinidase deficiency. Since August 2012 we included in ou newborn screening program one immunodeficiency and six