Mutation frequencies for glycogen storage disease IA in the Ashkenazi Jewish population

Dor Yeshorim, The Committee for the Prevention of Jewish Genetic Diseases, Brooklyn, New York, USA.
American Journal of Medical Genetics Part A (Impact Factor: 2.16). 08/2004; 129A(2):162-4. DOI: 10.1002/ajmg.a.30232
Source: PubMed


Glycogen storage disease type Ia (GSDIa) is a severe autosomal recessive disorder caused by deficiency of the enzyme D-glucose-6-phosphatase (G6Pase). While numerous mutations have been found in cosmopolitan European populations, Ashkenazi Jewish (AJ) patients appear to primarily carry the R83C mutation, but possibly also the Q347X mutation found generally in Caucasians. To determine the frequency for both these mutations in the AJ population, we tested 20,719 AJ subjects for the R83C mutation and 4,290 subjects for the Q347X mutation. We also evaluated the mutation status of 30 AJ GSDIa affected subjects. From the carrier screening, we found 290 subjects with R83C, for a carrier frequency for this mutation of 1.4%. This carrier frequency translates into a predicted disease prevalence of 1 in 20,000, five times higher than for the general Caucasian population, confirming a founder effect and elevated frequency of GSDIa in the AJ population. We observed no carriers of the Q347X mutation. Among the 30 GSDIa affected AJ subjects, all were homozygous for R83C. These results indicate that R83C is the only prevalent mutation for GSDIa in the Ashkenazi population.

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    • "GSDI has an estimated annual incidence of around 1/100,000 births, representing approximately 30% of hepatic GSD and with GSDIa being the most frequent type (about 80% of the GSDI patients)[1]. GSDIa is particularly common in the Ashkenazi Jewish population, in which the carrier frequency for the p.R83C allele was found to be 1.4%, predicting a prevalence five times higher than in the general Caucasian population [5]. "
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    ABSTRACT: Glucose-6-phosphatase deficiency (G6P deficiency), or glycogen storage disease type I (GSDI), is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, between the ages of 3 to 4 months by symptoms of hypoglycemia (tremors, seizures, cyanosis, apnea). Patients have poor tolerance to fasting, marked hepatomegaly, growth retardation (small stature and delayed puberty), generally improved by an appropriate diet, osteopenia and sometimes osteoporosis, full-cheeked round face, enlarged kydneys and platelet dysfunctions leading to frequent epistaxis. In addition, in GSDIb, neutropenia and neutrophil dysfunction are responsible for tendency towards infections, relapsing aphtous gingivostomatitis, and inflammatory bowel disease. Late complications are hepatic (adenomas with rare but possible transformation into hepatocarcinoma) and renal (glomerular hyperfiltration leading to proteinuria and sometimes to renal insufficiency). GSDI is caused by a dysfunction in the G6P system, a key step in the regulation of glycemia. The deficit concerns the catalytic subunit G6P-alpha (type Ia) which is restricted to expression in the liver, kidney and intestine, or the ubiquitously expressed G6P transporter (type Ib). Mutations in the genes G6PC (17q21) and SLC37A4 (11q23) respectively cause GSDIa and Ib. Many mutations have been identified in both genes,. Transmission is autosomal recessive. Diagnosis is based on clinical presentation, on abnormal basal values and absence of hyperglycemic response to glucagon. It can be confirmed by demonstrating a deficient activity of a G6P system component in a liver biopsy. To date, the diagnosis is most commonly confirmed by G6PC (GSDIa) or SLC37A4 (GSDIb) gene analysis, and the indications of liver biopsy to measure G6P activity are getting rarer and rarer. Differential diagnoses include the other GSDs, in particular type III (see this term). However, in GSDIII, glycemia and lactacidemia are high after a meal and low after a fast period (often with a later occurrence than that of type I). Primary liver tumors and Pepper syndrome (hepatic metastases of neuroblastoma) may be evoked but are easily ruled out through clinical and ultrasound data. Antenatal diagnosis is possible through molecular analysis of amniocytes or chorionic villous cells. Pre-implantatory genetic diagnosis may also be discussed. Genetic counseling should be offered to patients and their families. The dietary treatment aims at avoiding hypoglycemia (frequent meals, nocturnal enteral feeding through a nasogastric tube, and later oral addition of uncooked starch) and acidosis (restricted fructose and galactose intake). Liver transplantation, performed on the basis of poor metabolic control and/or hepatocarcinoma, corrects hypoglycemia, but renal involvement may continue to progress and neutropenia is not always corrected in type Ib. Kidney transplantation can be performed in case of severe renal insufficiency. Combined liver-kidney grafts have been performed in a few cases. Prognosis is usually good: late hepatic and renal complications may occur, however, with adapted management, patients have almost normal life span. Disease name and synonyms Glucose-6-phosphatase deficiency or G6P deficiency or glycogen storage disease type I or GSDI or type I glycogenosis or Von Gierke disease or Hepatorenal glycogenosis.
    Full-text · Article · May 2011 · Orphanet Journal of Rare Diseases
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    • "Out of 94 Jewish alleles characterized, all but two are p.R83C, with p.Q347X making up the balance. Indeed, GSD-Ia is particularly common in the Ashkenazi Jewish population where the carrier frequency for the p.R83C mutation is 1.4% [Ekstein et al., 2004]. "
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    ABSTRACT: Glucose-6-phosphatase-alpha (G6PC) is a key enzyme in glucose homeostasis that catalyzes the hydrolysis of glucose-6-phosphate to glucose and phosphate in the terminal step of gluconeogenesis and glycogenolysis. Mutations in the G6PC gene, located on chromosome 17q21, result in glycogen storage disease type Ia (GSD-Ia), an autosomal recessive metabolic disorder. GSD-Ia patients manifest a disturbed glucose homeostasis, characterized by fasting hypoglycemia, hepatomegaly, nephromegaly, hyperlipidemia, hyperuricemia, lactic acidemia, and growth retardation. G6PC is a highly hydrophobic glycoprotein, anchored in the membrane of the endoplasmic reticulum with the active center facing into the lumen. To date, 54 missense, 10 nonsense, 17 insertion/deletion, and three splicing mutations in the G6PC gene have been identified in more than 550 patients. Of these, 50 missense, two nonsense, and two insertion/deletion mutations have been functionally characterized for their effects on enzymatic activity and stability. While GSD-Ia is not more prevalent in any ethnic group, mutations unique to Caucasian, Oriental, and Jewish populations have been described. Despite this, GSD-Ia patients exhibit phenotypic heterogeneity and a stringent genotype-phenotype relationship does not exist.
    Preview · Article · Jul 2008 · Human Mutation
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    ABSTRACT: Smog chamber FTIR techniques were used to study the atmospheric oxidation of methyl propionate in 740 Torr of air in the presence of NOx at 296 ± 2K. Relative rate techniques were used to measure k(OH + CH3CH2C(O)OCH3) = (9.29 ± 1.13) × 10-13, k(Cl + CH3CH2C(O)OCH3) = (1.51 ± 0.22) × 10-11, k(Cl + CH3CH2C(O)OC(O)H) = (2.89 ± 0.35) × 10-12, k(Cl + CH3CH2C(O)OH) = (4.72 ± 0.62) × 10-12, and k(Cl + CH3C(O)C(O)OCH3) = (4.99 ± 0.96) × 10-13 cm3 molecule-1 s-1. The products (and molar yields) formed in the Cl-atom initiated oxidation of methyl propionate were as follows:  propionic formic anhydride (CH3CH2C(O)OC(O)H), 0.099 ± 0.019; propionic acid (CH3CH2C(O)OH), 0.139 ± 0.027; carbon monoxide, 0.132 ± 0.026; methyl pyruvate (CH3C(O)C(O)OCH3), 0.289 ± 0.057; acetaldehyde, 0.077 ± 0.015; methoxy formylperoxynitrate (CH3OC(O)O2NO2), 0.083 ± 0.016; methyl glyoxylate (H(O)CC(O)OCH3), 0.111 ± 0.022; organic nitrates, 0.07 ± 0.02; and formaldehyde. These products account for 79 ± 16% of the loss of methyl propionate. The atmospheric oxidation mechanism of methyl propionate is presented and discussed.
    No preview · Article · Nov 2000 · The Journal of Physical Chemistry A
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