Quantitation of plasmatic lysosphingomyelin and lysosphingomyelin-509 for differential screening of Niemann-Pick A/B and C diseases.

Acid sphingomyelinase deficiency (ASMd, Niemann-Pick disease A/B) and Niemann-Pick type C disease (NPC) share core clinical symptoms. Initial diagnostic discrimination of these two rare lysosomal storage diseases is thus difficult. As sphingomyelin accumulates in ASMd as well as NPC, lysosphingomyelin (sphingosylphosphorylcholine) and its m/z 509 analog were suggested as biomarkers for both diseases. Herein we present results of simultaneous LC-ESI-MS/MS measurements of lysosphingomyelin and lysosphingomyelin 509 in plasma and dried blood spots (DBS) collected from ASMd and NPC patients and suggest that the plasma but not DBS levels of the two analytes allow differential biochemical screening of ASMd and NPC.

Spondyloepimetaphyseal dysplasia with neurodegeneration associated with AIFM1 mutation - a novel phenotype of the mitochondrial disease.

In 1999, based on a single family, spondyloepimetaphyseal dysplasia (SEMD) with mental retardation (MR) was described as a novel syndrome with probably X-linked recessive inheritance and unknown molecular defect (MIM 300232). Our purpose was to search for the causative defect in the originally described family and in an independently ascertained second family. All patients had slowly progressive neurodegeneration with central and peripheral involvement and identical skeletal dysplasia. Whole exome sequencing performed in two subjects showed a single plausible candidate - the p.Asp237Gly variant in AIFM1 (chr. Xq26.1). The p.Asp237Gly segregated with disease as indicated by linkage analysis [maximum logarithm of odds score (LOD) score at theta 0 for the two families was 3.359]. This variant had not been previously reported and it was predicted to be pathogenic by Polyphen2, SIFT, MutationTaster and Mutation Assessor. AIFM1 encodes mitochondria associated apoptosis-inducing factor. The AIFM1 gene has been linked with COXPD6 encephalomyopathy (MIM 300816), Cowchock syndrome (MIM 310490) and X-linked deafness with neuropathy (DFNX5, MIM 300614), none of which are similar to SEMD-MR. Our results place SEMD as the third instance of a skeletal phenotype associated with a mitochondrial disease (the others being EVEN-PLUS syndrome caused by mutations of HSPA9 and CODAS syndrome due to LONP1 mutations).

Late onset GM2 gangliosidosis mimicking spinal muscular atrophy.

A case of late onset GM2 gangliosidodis with spinal muscular atrophy phenotype followed by cerebellar and extrapyramidal symptoms is presented. Genetic analysis revealed compound heterozygous mutation in exon 10 of the HEXA gene. Patient has normal intelligence and emotional reactivity. Neuroimaging tests of the brain showed only cerebellar atrophy consistent with MR spectroscopy (MRS) abnormalities. (18)F-fluorodeoxyglucose positron emission tomography (18)F-FDG PET/CT of the brain revealed glucose hypometabolism in cerebellum and in temporal and occipital lobes bilaterally.

Molecular and clinical consequences of novel mutations in the arylsulfatase A gene.

Metachromatic leukodystrophy (MLD), a severe neurodegenerative metabolic disorder, is caused by deficient activity of arylsulfatase A (ARSA; EC 3.1.6.8), which leads to a progressive demyelinating process in central and peripheral nervous systems. In this study, a DNA sequence analysis was performed on six Polish patients with different types of MLD. Six novel mutations were identified: one nonsense (p.R114X), three missense (p.G122C, p.G293C, p.C493F) and two frameshift mutations (g.445_446dupG and g.2590_2591dupC). Substitutions p.G293C and p.C493F and duplication g.445_446dupG caused a severe reduction of enzyme activity in transient transfection experiments on mammalian cells (less than 1% of wild-type (WT) ARSA activity). Duplication 2590_2591dupC preserved low-residual ARSA activity (10% of WT ARSA). In summary, the novel MLD-causing mutations in the exons 2, 5 and even in 8 of the ARSA gene described here can be classified as severe type 0, leading in homozygosity to the late infantile form MLD. Growth retardation, delayed motor development, gait disturbances, tonic-clonic seizures and non-epileptic muscle spasms were the first onset symptoms in patients with late infantile form of MLD. In individual with juvenile type MLD gait disturbances evidenced the onset of the disease, while in a patient with late juvenile MLD, difficulties at school were displayed.

Methods for a prompt and reliable laboratory diagnosis of Pompe disease: report from an international consensus meeting.

Pompe disease is an autosomal recessive disorder of glycogen metabolism caused by a deficiency of the lysosomal enzyme acid alpha-glucosidase (GAA). It presents at any age, with variable rates of progression ranging from a rapidly progressive course, often fatal by one-year of age, to a more slowly, but nevertheless relentlessly progressive course, resulting in significant morbidity and premature mortality. In infants, early initiation of enzyme replacement therapy is needed to gain the maximum therapeutic benefit, underscoring the need for early diagnosis. Several new methods for measuring GAA activity have been developed. The Pompe Disease Diagnostic Working Group met to review data generated using the new methods, and to establish a consensus regarding the application of the methods for the laboratory diagnosis of Pompe disease. Skin fibroblasts and muscle biopsy have traditionally been the samples of choice for measuring GAA activity. However, new methods using blood samples are rapidly becoming adopted because of their speed and convenience. Measuring GAA activity in blood samples should be performed under acidic conditions (pH 3.8-4.0), using up to 2 mM of the synthetic substrate 4-methylumbelliferyl-alpha-D-glucoside or glycogen (50 mg/mL), in the presence of acarbose (3-9 microM) to inhibit the isoenzyme maltase-glucoamylase. The activity of a reference enzyme should also be measured to confirm the quality of the sample. A second test should be done to support the diagnosis of Pompe disease until a program for external quality assurance and proficiency testing of the enzymatic diagnosis in blood is established.

Non-neuronopathic Gaucher disease due to saposin C deficiency.

Gaucher disease is generally caused by a deficiency of the lysosomal enzyme glucocerebrosidase. The degradation of glycosphingolipids requires also the participation of sphingolipid activator proteins. The prosaposin PSAP gene codes for a single protein which undergoes post-translational cleavage to yield four proteins named saposins A, B, C and D. Saposin (SAP-) C is required for glucosylceramide degradation, and its deficiency results in a variant form of Gaucher disease. In this report, we present clinical, biochemical, and molecular findings in a 36-year-old man and his 30-year-old sister with non-neuronopathic Gaucher disease due to SAP-C deficiency. Very high levels of chitotriosidase activity, chemokine CCL18, and increased concentration of glucosylceramide in plasma and normal beta-glucosidase activity in skin fibroblasts were observed in the patients. A molecular genetics study of the PSAP gene enabled the identification of one missense mutation, p.L349P, located in the SAP-C domain and another mutation, p.M1L, located in the initiation codon of the prosaposin precursor protein. The presented findings describe the first cases where the non-neuronopathic Gaucher disease has been definitely demonstrated to be a consequence of SAP-C deficiency. Three previously described cases in the literature displayed a Gaucher type 3 phenotype.

Assessment of relations between clinical outcome of ischemic stroke and activity of inflammatory processes in the acute phase based on examination of selected parameters.

BACKGROUND AND PURPOSES: Inflammatory factors play an important role in the pathogenesis of ischemic stroke. They may influence circulation during the acute phase of stroke and enhance the ischemic region. MATERIALS AND METHODS: We examined 51 patients--36 patients in the early stage of stroke, i.e. the first 24 h after onset. Of these, 15 patients had infection and 21 had no infection during the week preceding stroke. There were 15 patients with noninflammatory diseases in the control group. We analyzed parameters of inflammation such as: activity of serum chitotriosidase by fluorimetric assay, C-reactive proteins (CRP), number of white body cells (WBCs), IgG and fibrinogen. We also assessed the neurological stage according to the Scandinavian Stroke Scale (SSS). RESULTS: In our study, we observed a statistically significant difference (p < 0.05) in the activity of most parameters of inflammation. This difference could be seen in the levels of CRP, number of WBCs and the activity of chitotriosidase, apart from IgG and fibrinogen, between the control group and groups with versus without infection. A significantly increased level of CRP (p < 0.0005) and fibrinogen (p > 0.01) was found on the first day in the stroke group as compared to the control group. The neurological stage on day 4 after stroke, assessed according to the SSS, was significantly worse in the group of patients with infection before stroke than in stroke patients without infection (p < 0.008). CONCLUSION: These results suggest the importance of active inflammatory processes in the pathogenesis of stroke. We observed increased activity of chitotioridase, a parameter of the inflammatory process, in stroke. This study is one more proof that inflammatory processes caused by infection may influence the occurrence of stroke and worsen its outcome. It could be another step towards understanding immunological processes during the acute phase of stroke. The study may also help establish new diagnostic and therapeutic strategies and could be a useful tool for prophylaxis.

Molecular and phenotypic characteristics of metachromatic leukodystrophy patients from Poland.

The occurrence and genotype-phenotype correlations of the eight most common mutations in the arylsulfatase A (ARSA) gene were studied in 43 unrelated Polish patients suffering from different types of metachromatic leukodystrophy (MLD). Screening for mutations p.R84Q, p.S96F, c.459+1G>A, p.I179S, p.A212V, c.1204+1G>A, p.P426L, and c.1401-1411del allowed the identification of 53.5% of the mutant alleles. In the whole investigated group of patients, mutations c.459+1G>A and p.P426L were the most frequent, 19 and 17%, respectively. The prevalence of the third most frequent mutation, i.e. p.I179S (13%), seems to be higher than that in other populations. The incidence of c.1204+1G>A was 5%, which is higher than reported earlier (2%). It seems that p.I179S and c.1204+1G>A are more prevalent in MLD patients from Poland than from other countries. In the group examined by us, mutations p.R84Q, p.S96F, p.A212V, and c.1401-1411del were not detected; thus, 46.5% of MLD alleles remained unidentified. This indicates that other, novel or already described, but rare, mutations exist in Polish population. In late infantile homozygotes for c.459+1G>A and one homozygote for c.1204+1G>A, first clinical symptom was motor deterioration. In adult homozygotes for p.P426L, the disease onset manifested as gait disturbances, followed by choreoathetotic movements, difficulties in swallowing, dysarthria, tremor, and nystagmus. In the carriers of the p.I179S mutation, the hallmark of the clinical picture was psychotic disturbances.

Prevalence of arylsulfatase A pseudodeficiency allele in metachromatic leukodystrophy patients from Poland.

Arylsulfatase A (ASA) pseudodeficiency (PD) allele was searched for in 22 patients originating from Poland and suffering from different types of metachromatic leukodystrophy (MLD). Four of them carried the PD allele in a heterozygous state. The prevalence of the PD allele among investigated MLD patients was revealed to be 9%, while the frequency of the PD allele in healthy controls was estimated at 6-7%. One of the examined MLD patients was additionally a carrier of an isolated mutation leading to the loss of the N-glycosylation site. The question arises whether and how MLD mutations create a convenient milieu for PD mutations to occur (or inversely).

Practical suggestions in diagnosing metachromatic leukodystrophy in probands and in testing family members.

Metachromatic leukodystrophy (MLD) is one of the most severe genetically determined demyelination diseases. It is caused by a deficit in the activity of sulfatide sulfatase. The diagnosis is made by demonstrating a deficiency of arylsulfatase A (ASA) activity in leukocytes or cultured skin fibroblasts. Diagnosis based only on the activity of ASA is complicated by the fact that there exists a condition of ASA pseudodeficiency (Pd). Due to the relatively high risk of the MLD/Pd and MLDPd/Pd genotypes among families of patients, it is possible to make an erroneous diagnosis on the basis of only ASA activity. Nonetheless, it seems necessary to develop a reliable and simple diagnostic procedure so as to enable diagnosis and genetic counseling for carriers. We present two diagnostic flow charts entailing determination of ASA activity, identification of the pseudodeficit mutation and detection of sulfatides in a 24-hour urine collection.

Elevated sulfatide excretion in compound heterozygotes of metachromatic leukodystrophy and ASA-pseudodeficiency allele.

OBJECTIVE: Use of sulfatide excretion in differentiating MLD/PD-heterozygotes from MLD-patients and PD/PD-homozygotes. DESIGN AND METHODS: Sulfatide was extracted from urine sediment with chlorotom/methanol (2:1, v/v). The quantity of sulfatide was measured densitometrically (lambda = 580 nm) after thin-layer chromatography. ASA and beta-galactosidase activities were assayed enzymatically. RESULTS: MLD/PD-heterozygotes excreted sulfatide in the range of 4.8-36.3 nmol/mg lipid (mean +/- SD = 17.8 +/- 10.7), whereas sulfatide in MLD-patients ranged from 74.3-411.6 nmol/mg lipid (mean +/- SD = 184.5 +/- 130.8) and in PD/PD-hormozygotes sulfatide excretion remained in normal range of 0.0-5.9 nmol/mg lipid (mean +/- SD = 1.64 +/- 2.12). ASA activities in these groups were very low or lowered. CONCLUSIONS: The quantitative measurement of sulfatide in urine allows differentiation between MLD/PD-heterozygotes and MLD-heterozygotes, as well as between MLD/PD-heterozygotes with very low ASA activity and MLD-patients or PD/PD-hormozygotes. The quantitative measurement of sulfatide in urine differs between MLD-carriers and controls.

Occurrence, distribution, and phenotype of arylsulfatase A mutations in patients with metachromatic leukodystrophy.

Occurrence, distribution, and phenotype of arylsulfatase A (ASA) mutations were investigated in 27 patients with metachromatic leukodystrophy (MLD) from Central Europe, mainly from Austria (n = 15) and Poland (n = 9). Genomic DNA from leukocytes, fibroblasts, or paraffin-embedded, formalin-fixed brain or nerve tissue, respectively, was tested by natural or mutated primer-modulated PCR restriction, fragment length polymorphism for the eight most common European mutations: R84Q, S96F, 459+1G > A, I179S, A212V, 1204+1G > A, P426L, and 1401del11bp. The overall identification rate of unrelated MLD alleles was the highest, in adult (90%), medium in juvenile (50%), and lowest in late infantile (36%) MLD patients. The two common alleles, 459+1G > A and P426L, together accounted for 42% of all 50 unrelated MLD alleles investigated; I179S was observed in 6 of 50 MLD alleles (12%). Thus, I179S was far more frequent than hitherto thought and appears to be a third common mutation in Europe. Moreover, a different allelic distribution between Austrian and Polish juvenile patients was disclosed, indicating genetic heterogeneity of MLD even within Central Europe. The genotype-phenotype correlation suggested by Polten et al. [N Engl J Med 324:18-22, 1991] was not followed by all of our MLD patients. Moreover, some MLD patients with identical ASA mutations presented with different phenotypes. This may be due, at least in some cases, to the presence of an additional mutation on individual mutant alleles. Therefore, prediction of the clinical course from single mutation analysis is not possible.

Clinical, biochemical and histological analysis of seven patients with cholesteryl ester storage disease.

Lysosomal acid lipase (LAL) deficiency leads to two phenotypically different diseases: cholesteryl ester storage disease (CESD) and Wolman's disease. Lysosomal acid lipase hydrolyzes cholesteryl esters and triglycerides. Deficiency of LAL results in intralysosomal storage of cholesteryl esters and triglycerides. CESD has a chronic and benign course and is characterized by hepatomegaly and mild hypercholesterolemia. It leads to fibrosis (cirrhosis) and early atherosclerosis. This report presents the clinical, biochemical and microscopic data of seven patients with CESD followed up over 10 years. The physical development of all the study children remained within the normal range; 7 patients had hepatomegaly and 6 also had splenomegaly. Three patients had normal cholesterol, triglycerides and transaminases values; the other four had slightly elevated levels for these parameters. The activity of LAL in all patients was reduced to below 30% of the lower normal value. Histologically, cholesteryl crystals and lipid storage vacuoles in Kupffer cells were present in all examined patients except one. Accumulation of cholesteryl esters was visible on thin-layer chromatography of lipid extracts obtained from liver biopsies.

Late juvenile metachromatic leukodystrophy (MLD) in three patients with a similar clinical course and identical mutation on one allele.

Metachromatic leukodystrophy (MLD) is an autosomal, recessively inherited, lysosomal storage disease caused by arylsulfatase A (ASA) activity deficit. Arylsulfatase A initiates the degradation of sulfatide (cerebroside sulfate), which is an essential component of myelin. The main clinical symptoms are caused by progressive demyelination. At least 34 MLD-related ASA mutations are known to date. I179S (E3P799) is a disease-related mutation, described for the first time by Fluharty in 1991. This aberration appears to substantially reduce, but not completely eliminate ASA activity, and was detected in individuals with late-onset (juvenile or adult) forms of MLD. This paper deals with the peculiar clinical course in three unrelated juveniles with late-onset MLD carrying the I179S mutations on one allele. In the three described patients with the I179S mutation, psychiatric disturbances and intellectual impairment dominated the clinical picture, while the neurological lesions progressed more slowly. Although the symptoms appeared rather early, making it possible to classify this as the juvenile type of MLD, the clinical picture was more that of the adult type. Although the mutations on the second allele in our patients are unknown, one can speculate, that the mutation I179S plays an important role in the characteristic clinical course (psychiatric impairment, slower neurological deterioration, but relatively early onset). It seems that I179S mutation on one allele with another mutation on the other allele reduces ASA activity, but the enzyme can still cope with a part of the substrate influx, leading to late-juvenile-onset MLD with such strikingly similar phenotypes remaining a little bit of the adult (psychiatric) type. This could be one more argument in favour of phenotype-genotype correlation in patients with MLD.

Neuraminidase deficiency presenting as a nephrosialidosis: the first case detected in Poland.

A defect of lysosomal neuraminidase (sialidase N-acetyl-neuramine acid hydrolase EC 3.2.1.18) leads to a wide spectrum of phenotypes, the most severe of which is nephrosialidosis. A 4-year-old boy of related parents, born at term with hydrops fetalis, is reported. Hydrocephalus was detected at 2 months of age. The child's course over 3 years was characterized by slow growth and psychomotor development. He had mild hepatosplenomegaly, joint restriction, gingival hypertrophy, lens opacities and cherry-red spot. Coarse facial features and depressed nasal bridge were discreet. At the age of 3.5 years, he developed gradual progressive edema, decreased activity and increased fatigue. A diagnosis of nephrotic syndrome was made because of massive proteinuria. Thin-layer chromatography of urinary oligosaccharides revealed the presence of several abnormal sialyloligosaccharides. The diagnosis was confirmed by measurement of neuraminidase activity in cultured skin fibroblasts.

[Thin-layer chromatography of urine oligosaccharides in diagnosis of some lysosomal storage disorders]. / Chromatografia cienkowarstwowa oligosacharydów moczu w diagnostyce niektórych chorób lizosomalnych.

Inherited lysosomal storage disorders are caused by the deficiency or importantly lowered activity of one of the lysosomal enzymes, leading to the storage in the lysosomes the not degraded high-molecular substrates, among others: mucopolysaccharides, glycolipids, oligosaccharides and glycoproteins. Thin-layer chromatography of urine oligosaccharides allows reliable and fast diagnosis of some lysosomal storage disorders e.g. alpha-mannosidosis, fucosidosis, sialidosis, galactosialidosis, Schindler disease, GM1-gangliosidosis, GM2-gangliosidosis (Sandhoff type), Pompe disease, Salla disease, mucolipidosis II and III. We are presenting a modification of the Humbel and Collart's method of TLC of urine oligosaccharides. The principle of our modification is to introduce of the preliminary desalting step of the urine on the columns containing anionit BioRad AG 1 x 8 and cationit Dowex 50 x 8-200.