Late infantile neuronal ceroid lipofuscinosis: quantitative description of the clinical course in patients with CLN2 mutations

We examined 26 individuals with clinical and electron microscopic signs of late infantile neuronal ceroid lipofuscinosis (LINCL). In 22 cases, we found both pathogenic alleles. Sixteen patients exclusively carried either one or a combination of the two common mutations R208X and IVS5-1G > C. In the remaining cases, four missense mutations could be detected, of which R127Q, N286S, and T353P represent novel, previously not described alleles. A clinical performance score was developed by rating motor, visual, and verbal functions and the incidence of cerebral seizures in 3-month intervals during the course of the disease. A Total Disability Score was derived by summing up the single scores for motor, visual, and verbal functions. The 16 individuals with the two common mutations were grouped together (referred to as standard patients), and the 5th, 50th, and 95th centiles were calculated and graphically depicted over time. The scores for motor function and language ability dropped earliest and progressed very similarly in the standard patients. The performance curves of two children with the N286S mutation slightly diverged from the 95th centile. However, the performance curves of one patient with atypical LINCL carrying the R127Q mutation fell far beyond the 95th centile. The presented performance rating clearly and quantitatively delineates the disease course of the LINCL patients and hence offers a useful tool for clinical evaluation of future therapeutic interventions. In addition, the described performance score system can be applied to other types of neuronal ceroid lipofuscinoses and could be adapted to various other neurodegenerative diseases of childhood.     

The spectrum of aldolase B (ALDOB) mutations and the prevalence of hereditary fructose intolerance in Central Europe

We investigated the molecular basis of hereditary fructose intolerance (HFI) in 80 patients from 72 families by means of a PCR-based mutation screening strategy, consisting of heteroduplex analysis, restriction enzyme digest, DNA single strand electrophoresis, and direct sequencing. For a subset of patients mutation screening with DHPLC was established which turned out to be as fast and as sensitive as the more conventional methods. Fifteen different mutations of the aldolase B (ALDOB) gene were identified in HFI patients. As in smaller previous studies, p.A150P (65%), p.A175D (11%) and p.N335K (8%) were the most common mutated alleles, followed by c.360_363delCAAA, p.R60X, p.Y204X, and c.865delC. Eight novel mutations were identified in eight families with HFI: a small indel mutation (c.1044_1049delTTCTGGinsACACT), two small deletions (c.345_372del28; c.841_842delAC), two splice site mutations (c.113-1G>A, c.799+2T>A), one nonsense mutation (c.612T>G (p.Y204X)), and two missense mutations (c.532T>C (p.C178R), c.851T>C (p.L284P)). By mutation screening for the three most common ALDOB mutations by DHPLC in 2,000 randomly selected newborns we detected 21 heterozygotes. Based on these data and after correction for less common and private ALDOB mutations, HFI prevalence in central Europe is estimated to be 1:26,100 (95% confidence interval 1: 12,600-79,000).     

Methylamine accumulation in cultured cells as a measure of the aqueous storage compartment in the laboratory diagnosis of genetic lysosomal diseases

Intracellular accumulation of the lysosomotropic compound [¹⁴C]methylamine was used to estimate the size of the lysosomal compartment in fibroblasts cultured from patients with a variety of lysosomal storage diseases. In previous work from our laboratory, it was shown that methylamine accumulation was significantly increased in diseases with infantile or juvenile onset and storage of predominantly water-soluble material such as in the mucopolysaccharidoses, mucolipidoses, and oligosaccharidoses. In the present study, methylamine incorporation was abnormally increased in cells from patients with glycogenosis type II and with Niemann-Pick type C disease, whereas it was normal in other sphingolipidoses and in the late-infantile and juvenile forms of neuronal ceroid lipofuscinoses. The methylamine test was also checked regarding its potential use for prenatal diagnostic testing. In model systems with cultured amniotic or chorionic villus cells, lysosomal storage was experimentally induced by the cathepsin inhibitor leupeptin and was readily detected when compared to untreated controls. Cultured amniotic cells from a fetus with mucopolysaccharidosis II were found to incorporate significantly higher amounts of [¹⁴C]methylamine than the normal controls. The results indicate that the methylamine accumulation method is an additional tool in the diagnosis and prenatal diagnosis of lysosomal diseases with abnormal storage of water-soluble material. © 1996 Wiley-Liss, Inc.     

Radical trapping in glycogen storage disease 1a

Oxidative mechanisms involving lipid peroxidation in the subendothelium of the arterial vessel wall play a key role in atherogenesis. Despite severe hyperlipidaemia, patients with glycogen storage disease type la (GSD1a) do not develop premature atherosclerosis. Therefore, we analysed parameters of antioxidative defence and oxidative stress in plasma and serum of patients with GSD1a (n=17) and compared them with those of patients with type 1 diabetes mellitus (n=17), familial hypercholesterolaemia (n=18) and healthy controls (n=20). We measured the total radical trapping ability parameter (TRAP), single plasma antioxidants (sulfhydryl-groups, uric acid, vitamin C, alpha-tocopherol, coenzyme-Q10), markers of lipid peroxidation, lipoprotein (a) and homocysteine. Patients with GSD1a showed an elevated TRAP (P<0.01) compared to the three other groups. This can mainly be attributed to elevated uric acid levels (P<0.05 versus control). Lipoprotein (a) was significantly lower in the GSD1a group compared to the three other groups (P<0.05).Conclusion: Patients with glycogen storage disease type 1a show an increased antioxidative defence in plasma which may protect them against lipid peroxidation and thus against premature atherosclerosis. Our finding of low lipoprotein (a) levels in this small group of patients warrants further investigation in a greater number of patients before assessing its role in atherogenesis in glycogen storage disease type 1a. Published online: 19 September 2002     

Occlusion of pseudoaneurysms using human or bovine thrombin using contrast-enhanced ultrasound guidance

Percutaneous thrombin occlusion of pseudoaneurysms complicating invasive coronary interventions has emerged as a useful therapeutic tool. To facilitate thrombin occlusion and make the procedure even more secure, preinjection of echo contrast medium during duplex ultrasound was tested in 132 patients. Complete and immediate occlusion of the pseudoaneurysm was achieved in 99.2% (131 of 132 patients). No complications related to the injection of thrombin were documented. Contrast-enhanced ultrasound-guided thrombin occlusion was a safe and effective therapeutic option. In aneurysms with complex morphology or multiple cavities, preinjection of contrast medium was helpful for documenting the flow pattern.     

Normal brain maturation characterized with age-related T2 relaxation times: an attempt to develop a quantitative imaging measure for clinical use

OBJECTIVES: We studied age-related changes in T2 relaxation times from the normal maturating human brain under routine clinical MR examination conditions. MATERIALS AND METHODS: In 70 healthy subjects aged between 3 weeks and 39 years, T2 maps of the brain in which the intensity of each pixel corresponded to T2 relaxation times were generated based on magnetic resonance imaging data collected with a triple spin echo sequence. T2 relaxation times in white matter (WM) and gray matter (GM) were measured in 6 distinctive regions of interest of the T2 maps. The age dependence of the T2 values was mathematically simulated using a biexponential function. RESULTS: T2 values were largest at the age of 3 weeks (maximum: approximately 400 milliseconds for WM and 200 milliseconds for GM) and decreased continuously with increasing age, faster in the first few months and slower thereafter, until values achieved between 95 and 110 milliseconds for WM and 88 and 95 milliseconds for GM in adults. The relationship between T2 values and age could be well simulated using a biexponential function (R > 0.92). CONCLUSIONS: T2 relaxation time correlates well with the progress of brain maturation. The used biexponential function reflects the dynamic development of myelination in newborns and young children as well as the maturation of myelination during adolescence and could be used to develop a "normal" reference for neuroradiological diagnoses.     

Atypical focal MRI lesions in a case of juvenile Alexander's disease

We present a juvenile case of Alexander's disease with atypical focal magnetic resonance imaging-detected lesions and elevated levels of lactate in cerebrospinal fluid. The diagnosis was based on the neuropathological finding of a diffuse accumulation of Rosenthal fibers within the brain and the spinal cord. The diagnosis was confirmed by detection of a mutation in exon 1 at nucleotide position 249 of glial fibrillary acidic protein cDNA, a finding previously reported in cases of infantile Alexander's disease.