Three successful pregnancies through dietary management of fructose-1,6-bisphosphatase deficiency.

Fructose-1,6-bisphosphatase (FBPase) deficiency (OMIM 229700) has been characterized as the cause of life-threatening hypoglycaemia and lactic acidaemia following prolonged fasting. The patient, an adult African-American woman, presented during the second trimester of her first pregnancy with recurrent episodes of lactic acidaemia and hypoglycaemia. She had recently been admitted to a nearby intensive care unit after presentation with profound hypoglycaemia and lactic acidosis, and was found to be pregnant. The history was remarkable for approximately 30 hospitalizations for hypoglycaemia and acidosis. She had previously undergone liver biopsy at another centre and was diagnosed with a 'glycogen storage disease', although no enzyme testing had been done for confirmation. Based on clinical symptoms, a diagnosis of FBPase deficiency was accomplished through gene sequencing, which revealed homozygosity for a panethnic, common mutation, 960/961insG in exon 7. The availability of mutation testing facilitated the confirmation of FBPase deficiency in this patient, obviating liver biopsy for enzyme activity confirmation. The patient underwent three successful pregnancies by strict compliance with dietary management, including nocturnal uncooked cornstarch to manage hypoglycaemia. The pregnancies were complicated by mild gestational diabetes, increased cornstarch requirements, and hypoglycaemia at the time of discharge from the hospital. The three infants had normal birth weights and experienced no complications during the neonatal period. The patient subsequently developed sensorineural hearing loss and early-onset cognitive impairment, despite compliance with the monitoring and treatment of hypoglycaemia. The experience with multiple pregnancies in this FBPase-deficient patient provides insight into the management of hypoglycaemia in inherited disorders of gluconeogenesis.

Hepatocellular carcinoma in glycogen storage disease type Ia: a case series.

We present a series of 8 patients (6 males, 2 females) with hepatocellular carcinoma (HCC) and glycogen storage disease type Ia (GSD Ia). In this group, the age at which treatment was initiated ranged from birth to 39 years (mean 9.9 years). All patients but one were noncompliant with treatment. Hepatic masses were first detected at an age range of 13-45 years (mean 28.1 years). Age at diagnosis of HCC ranged from 19 to 49 years (mean 36.9 years). Duration between the diagnosis of liver adenomas and the diagnosis of HCC ranged from 0 to 28 years (mean 8.8 years, SD = 11.5). Two patients had positive hepatitis serologies (one hepatitis B, one hepatitis C). Alpha-fetoprotein (AFP) was normal in 6 of the 8 patients. Carcinoembryonic antigen (CEA) was normal in the 5 patients in which it was measured. Current guidelines recommend abdominal ultrasonography with AFP and CEA levels every 3 months once patients develop hepatic lesions. Abdominal CT or MRI is advised when the lesions are large or poorly defined or are growing larger. We question the reliability of AFP and CEA as markers for HCC in GSD Ia. Aggressive interventional management of masses with rapid growth or poorly defined margins may be necessary to prevent the development of HCC in this patient population.

Evaluation of 3-methylcrotonyl-CoA carboxylase deficiency detected by tandem mass spectrometry newborn screening.

Since the addition of tandem mass spectrometry (MS/MS) to the North Carolina Newborn Screening Program, 20 infants with two consecutive elevated 3-hydroxyisovalerylcarnitine (C5OH) levels have been evaluated for evidence of inborn errors of metabolism associated with this metabolite. Ten of these 20 infants had significant concentrations of both 3-hydroxyisovaleric acid and 3-methylcrotonylglycine in their urine, suggestive of 3-methylcrotonyl-CoA carboxylase (3-MCC) deficiency. Four of these 10 were infants whose abnormal metabolites were found to be of maternal origin. Of 8 patients with probable 3-MCC deficiency, 7 have been tested and found to have the enzyme deficiency confirmed in lymphoblasts or cultured fibroblasts; one of these 7 infants had only marginally decreased 3-MCC activity in lymphocytes but deficient 3-MCC in fibroblasts. We estimate the incidence of 3-MCC deficiency at 1:64000 live births in North Carolina. We conclude that MS/MS newborn screening will detect additional inborn errors of metabolism, such as 3-MCC deficiency, not traditionally associated with newborn screening. The evaluation of newborns with two abnormally elevated C5OH levels on MS/MS newborn screening should include, at least, urine organic acid analysis by capillary GC-MS and a plasma acylcarnitine profile by MS/MS. Long-term follow-up is needed to determine the outcome of presymptomatically diagnosed patients with 3-MCC deficiency by MS/MS newborn screening.

Delivery of glucose-6-phosphatase in a canine model for glycogen storage disease, type Ia, with adeno-associated virus (AAV) vectors.

Therapy in glycogen storage disease type Ia (GSD Ia), an inherited disorder of carbohydrate metabolism, relies on nutritional support that postpones but fails to prevent long-term complications of GSD Ia. In the canine model for GSD Ia, we evaluated the potential of intravenously delivered adeno-associated virus (AAV) vectors for gene therapy. In three affected canines, liver glycogen was reduced following hepatic expression of canine glucose-6-phosphatase (G6Pase). Two months after AAV vector administration, one affected dog had normalization of fasting glucose, cholesterol, triglycerides, and lactic acid. Concatamerized AAV vector DNA was confirmed by Southern blot analysis of liver DNA isolated from treated dogs, as head-to-tail, head-to-head, and tail-to-tail concatamers. Six weeks after vector administration, the level of vector DNA signal in each dog varied from one to five copies per cell, consistent with variation in the efficiency of transduction within the liver. AAV vector administration in the canine model for GSD Ia resulted in sustained G6Pase expression and improvement in liver histology and in biochemical parameters.

Frequency of celiac disease in individuals with Down syndrome in the United States.

Ninety-three individuals with Down syndrome (DS) were screened to investigate the prevalence of celiac disease (CD) in the United States. Five of the 93 individuals were antiendomysial antibody (EMA) positive. Of the 5 who tested positive for EMA, 4 were biopsied, 1 refused biopsy. Three of the 4 individuals biopsied manifested changes of CD on small bowel biopsy. This gives a frequency of 3.2% of confirmed CD in our DS individuals and suggests the need for periodic screening for celiac disease in this population.

Canine model and genomic structural organization of glycogen storage disease type Ia (GSD Ia).

A canine model of glycogen storage disease Ia (GSD Ia), similar clinically, biochemically, and pathologically to the human disease, was established by crossbreeding Maltese and Beagle dogs carrying a mutated, defective glucose-6-phosphatase (G-6-Pase) gene. Ten puppies were born in three litters from these crossbreedings. Six were homozygous for the previously described M121I GSD Ia mutation. Of these six affecteds, two were stillborn, and one died at 2, 32, and 60 days of life, respectively (puppies A, B, C, D, E), while one is alive at age 15 months (puppy F). Affected puppies exhibited tremors, weakness, and neurologic signs when hypoglycemic. They had postnatal growth retardation and progressive hepatomegaly. Biochemical abnormalities included fasting hypoglycemia, hyperlactacidemia, hypercholesterolemia, hypertriglyceridemia, and hyperuricemia. Microscopic examination of tissues from affected puppies showed diffuse, marked hepatocellular vacuolation, with distended clear hepatocytes and central to marginally located rounded nuclei. In the kidneys of puppies D and E, there was segmental glomerular sclerosis and vacuolation of proximal convoluted tubular epithelium. Biochemical analysis revealed increased liver glycogen content and isolated markedly reduced G-6-Pase enzyme activity in liver and kidney. The canine G-6-Pase gene was characterized by screening a canine genomic library. It spans approximately 11.8 kb and consists of five exons with >90% amino acid sequence homology to the derived human sequence. The first 1.5 kb of the 5' region was sequenced and contains several putative response element motifs homologous to the human 5' region. Establishment of this canine colony of GSD Ia that closely resembles human disease and isolation of the canine genomic gene provides an excellent model for studying pathophysiology and long-term complications and an opportunity to develop novel therapeutic approaches such as drug and gene therapy.

Nutritional deficiencies in a patient with glycogen storage disease type Ib.

The current mainstay of treatment in glycogen storage disease type I (GSD I) is dietary management that includes providing a frequent source of glucose to prevent hypoglycaemia. To ensure compliance, routine follow-up by a health care team, including a dietitian, experienced in the treatment of GSD is necessary. We describe an adolescent patient with GSD Ib in good metabolic control who was admitted with a 3-month history of weakness, depression, vomiting, decreased appetite and a 11.4-kg weight loss. He had a recent onset of unsteady gait, inability to write, and sore mouth. After an extensive work-up, the patient was found to have vitamin B12, folate, iron and other nutritional deficiencies, which explained his symptoms. The patient improved within 72 h of initiation of total parenteral nutrition and therapeutic doses of deficient micronutrients, with a complete recovery in 2 months. Dietary restrictions, dependence on non-food products (e.g. cornstarch in GSD I), and social and developmental issues place individuals with metabolic disorders at a high risk for developing an array of nutritional deficiencies. This case highlights the importance of both close follow-up of the metabolic control and close monitoring of growth and nutritional intake in individuals with inborn errors of metabolism. This case also illustrates the importance of daily supplementation with appropriate multivitamins, calcium and other minerals needed to meet the Recommended Dietary Allowances (RDAs) in these patients.

Nutrition risk classification: a reproducible and valid tool for nurses.

BACKGROUND: Incorporating the nursing staff to assist with the screening process on admission will allow patients who are at nutritional risk to be assessed by registered dietitians earlier in their hospital stay. The goal of this study was to develop an objective, valid, reproducible nutrition screen for use by registered nurses (RNs) to allow for nutrition classifications of hospitalized patients. METHODS: The current nursing admission assessment form was modified to contain questions on weight loss history, percentage of ideal body weight, and alterations in dietary intake and gastrointestinal function. Assessments were completed within 48 hours of admission. On the basis of the answers to these questions, patients were classified as "at nutritional risk" or "low nutritional risk." In phase 1, to assess reproducibility of the form, a prospective study between staff RNs and a nutritionist was undertaken on 186 consecutive adult admissions. Nutrition screening and classification was done independently by both practitioners. In phase 2 of the study, prospective validation of the form contrasting prealbumin (PAB) levels with RN nutritional risk classification (n = 56) was investigated. RESULTS: Interobserver agreement of nutrition classification between RN and nutritionist was 97.3% (p = .95). Twenty-nine patients were classified at low nutritional risk (27 normal PAB and 2 low PAB); 27 patients were classified as at nutritional risk (16 normal PAB and 11 low PAB) (chi 2 = 8.9, p < .003, power 0.8). The sensitivity of the tool was 84.6%. CONCLUSION: To our knowledge, this is the first nutrition screening tool designed for staff RNs that has been tested for both validity and reproducibility.

Clinical and laboratory findings in four patients with the non-progressive hepatic form of type IV glycogen storage disease.

The classic clinical presentation for type IV glycogen storage disease (branching enzyme deficiency, GSD IV) is hepatosplenomegaly with failure to thrive occurring in the first 18 months of life, followed by progressive liver failure and death by age 5 years. Although there have been two patients without apparent liver progression previously reported, no long-term follow-up clinical data have been available. We present here the clinical spectrum of the non-progressive liver form of GSD IV in four patients, and long-term follow-up of the oldest identified patients (ages 13 and 20 years). None has developed progressive liver cirrhosis, skeletal muscle, cardiac or neurological involvement, and none has been transplanted. Branching enzyme activity was also measured in cultured skin fibroblasts from patients with the classic liver progressive, the early neonatal fatal, and the non-progressive hepatic presentations of GSD IV. The residual branching enzyme activity in the patients without progression was not distinguishable from the other forms and could not be used to predict the clinical course. Our data indicate that GSD IV does not always necessitate hepatic transplantation and that caution should be used when counselling patients regarding the prognosis of GSD IV. Patients should be carefully monitored for evidence of progression before recommending liver transplantation.

The effect of ionic stress on photosynthesis in Dunaliella tertiolecta : Chlorophyll fluorescence kinetics and spectral characteristics.

A comparison of the effects of ionic stress and an uncoupler on long-term fluorescence transients (the 'Kautsky effect') in the green alga Dunaliella tertiolecta indicated that the large quenching induced by ionic stress was caused by a pH gradient across the thylakoid membrane. This possiblity was given support by the increase in the slow phase of 3-(3',4'-dichlorophenyl)-1,1-dimethylurea-induced fluorescence relaxation in algae subjected to ionic stress. Low-temperature fluorescence emission spectra indicated that salt stress enhanced photosystem-I emission in the dark, and a comparison of simultaneous emissions at 695 and 720 nm at room temperature indicated a further increase in photosystem-I emission during the fluorescence transients. Taken together with the decrease in the fast phase of 3-(3',4'-dichlorophenyl)-1,1-dimethylurea-induced fluorescence relaxation in stressed algae, our results indicate that ionic stress stimulates cyclic electron flow, and that non-cyclic flow is inhibited. The effect of sucrose-induced osmotic stress was similar to, but less marked than, the effects of NaCl and KCl; the effect of decreasing the external salinity was small.

The effects of coumarin on the growth and viability of sporelings of red algae.

The growth of sporelings of the red algae Plumaria elegans, Antithamnion plumula and Polysiphonia brodiaei was markedly influenced by coumarin. Growth of Plumaria and Antithamnion was totally inhibited by immersion for 7 days in media containing 200 mg coumarin/l, and showed 46% and 41% growth inhibition respectively in 100 mg coumarin/l; a significant reduction in growth was obtained in 50 mg/l of the phytostatic agent (e.g. 15% growth inhibition with Plumaria; and 10% with Antithamnion). A noticeable stimulation of growth was observed in 10 mg coumarin/l. The viabilities of the sporelings remained high after immersion in the toxic agent. The inhibitory effects were of a similar order both with the young plants treated immediately after commencement of growth, and with sporelings grown normally for 14 days before contact with coumarin. With Plumaria sporelings the maximum inhibitory effects were observed after 3 days immersion in 200 mg coumarin/l, and after 5 days in 100 mg coumarin/l. Immersion for 7 days in 200 mg/l of the reagent induced irreversible changes in the sporelings; such effects were less marked at 100 mg/l; and at 50 mg/l there was a complete recovery from the effects of the compound when speorelings were transferred to normal culture medium. The significance of the results is discussed in terms of the possible factors involved which may influence sporeling growth.