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To simplify the process of transfection of human fibroblasts and to acquire a suitable number of transformants, we investigated experimental conditions of electric pulse-induced transfection of human fibroblasts using origin-defective simian virus 40 DNA (SV40 (ori-) DNA). Voltage, pulse duration, number of pulses and the concentration of SV40 (ori-) DNA led to the formation of 10 to 30 foci/25 cm2 6 weeks after transfection, using 2 to 3 x 10(6) cells and a square wave pulse generator. Optimal condition was determined to be 2 or 3 pulses at a voltage of 1500 to 2000 V/0.4 cm with 30 microseconds pulse width, using 2 micrograms of linearized SV40 (ori-) DNA. With this approach we developed human transformed fibroblasts cell lines with all types of mucopolysaccharidoses. The transformed fibroblasts grew rapidly and the saturation density exceeded that of the parental cells. All the transformed cell clones expressed T antigen, and deficiency in specific enzymes was conserved. A point mutation which occurred in the human beta-glucuronidase gene in a patient with mucopolysaccharidosis type VII was also conserved.

Four cases of mucopolysaccharidosis or mucolipidosis and carpal tunnel syndrome in children are presented. Carpal tunnel release achieved clinical and electrical improvement in all cases.

A sensitive and specific, monoclonal antibody-based immunoquantification assay has facilitated determination of the N-acetylgalactosamine-4-sulfatase (4-sulfatase) protein content in cultured fibroblasts from normal controls and mucopolysaccharidosis type VI (MPS VI) patients. The assay enabled the quantification of 4-sulfatase protein by using a panel of seven monoclonal antibodies and has shown that fibroblasts from 16 MPS VI patients contained less than or equal to 5% of the level determined for normal controls. Fibroblasts from the most severely affected patients contained the lowest levels of 4-sulfatase protein, usually with few epitopes detected, while fibroblasts from mildly affected patients had higher levels of 4-sulfatase protein, with all seven epitopes detected. The pattern of epitope expression is proposed to reflect the conformational changes in the 4-sulfatase protein that arise from different mutations in the 4-sulfatase gene. Immunoquantification in combination with a specific and highly sensitive 4-sulfated trisaccharide-based assay of enzyme activity in these MPS VI patient fibroblasts enabled the determination of residual 4-sulfatase catalytic efficiency (kcat/Km). The capacity of fibroblasts to degrade substrate (catalytic capacity) was calculated as the product of 4-sulfatase catalytic efficiency and the content of 4-sulfatase in fibroblasts. One patient, 2357, with no clinical signs of MPS VI but with reduced 4-sulfatase activity and protein (both 5% of normal) and dermatansulfaturia, had 5% of normal catalytic capacity. The other 15 MPS VI patient fibroblasts had 0%-1.4% of the catalytic capacity of fibroblasts from normal controls and were representative of the spectrum of MPS VI clinical phenotypes, from severe to mild.(ABSTRACT TRUNCATED AT 250 WORDS)

The mucopolysaccharidoses represent a group of lysosomal storage disorders characterized by coarse facies, skeletal deformities, and often mental deterioration. Recent clinical and biochemical studies have revealed a broad genetic heterogeneity of these metabolic diseases: An identical enzyme defect may lead to a mild form with normal adult height and normal life expectancy or to a severe hydrops fetalis that does not survive the first days of life. Conversely, Sanfilippo disease is an example that identical phenotypes may result from mutations of different genes. From clinical observations it became clear, that not only the skin, brain and skeletal system are involved in the storage process, but also the lungs and the cardiovascular system. Until recently, no more than palliative treatment could be offered. This consists of corneal transplantation, cervical fusion to prevent atlantoaxial subluxation, especially in Morquio's disease, and shunt operation to relieve hydrocephalus. In the last decade bone marrow transplantation became available; this may have beneficial effects in selected cases, especially in mucopolysaccharidosis I. Since the genes of several lysosomal enzymes have been identified, many efforts to introduce the normal gene into the affected cells were done. This method was successfully applied in an animal model. But many efforts in several laboratories are still necessary until this therapeutic regimen will become available for patients with mucopolysaccharidosis.

We identified two different exonic point mutations causing beta-glucuronidase (beta G1) deficiency in two Japanese patients with mucopolysaccharidosis type VII (MPSVII). Enzyme assay of lysates of the lymphocytes and cultured fibroblasts showed little residual activity. The beta G1-specific mRNA levels were normal, as determined by northern blot analysis. Mutated cDNA clones, including the entire coding sequence, were isolated using the polymerase chain reaction (PCR) products derived from beta G1-deficient fibroblasts. Sequence analysis of the full-length mutated cDNAs showed C----T transitions, which resulted in a single Ala619----Val change (case 1, a 24-year-old male) and a Arg382----Cys change (case 2, a 7-year-old female). The former change was revealed by a loss of the cleavage site for the Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient (case 1) was a homozygote with this mutation. The mutational change in patient 2 was confirmed by direct sequencing and by demonstrating heterozygosity for the mutation in her parents. The Ala619----Val and Arg382----Cys mutations each disrupt a different domain which is highly conserved among human, rat, and Escherichia coli beta G1s. Each of these two amino acid changes reduced the beta G1 activity of the corresponding mutant beta G1 expressed following transfection of COS cells with expression vectors harboring the mutated cDNAs.

Scheie syndrome is a rare inborn error of metabolism, a mucopolysaccharidosis in which deficiency of the lysosomal enzyme alpha-L-iduronidase leads to tissue accumulation of mucopolysaccharides. Scheie syndrome is a forme fruste of Hurler syndrome (gargoylism), and some patients have the phenotype of Hurler-Scheie compound syndrome. The craniofacial abnormalities include coarse facies, mandibular condylar hypoplasia, retarded tooth eruption, and cystic jaw radiolucencies--particularly about the molars. Corneal clouding may lead to blindness but, in contrast to some other mucopolysaccharidoses, mental handicap is rare in Scheie syndrome. Cardiac valve incompetence is common, as are recurrent respiratory infections. Two brothers with Hurler-Scheie syndrome are presented and the oral and systemic complications each patient had described. The syndrome is discussed with particular reference to the orofacial features.

Clinical, ultrastructural and biochemical studies are reported in a 42-year-old woman presenting with congenital pes cavus who, at the age of 23 years, developed slowly progressive distal amyotrophies, hypesthesia, bilateral hearing loss and severe cardiopathy leading to death. There were skeletal anomalies, mild reduction of motor NCVs, but no corneal opacity, retinitis pigmentosa, organomegaly or vacuolated lymphocytes. Autopsy disclosed severe thickening of fibrous tissues (endocardium, cerebrospinal dura) with accumulation of vacuolated cells containing glycosaminoglycans in numerous membrane-bound cytoplasmic vacuoles, and/or compound multilamellar or zebra-body-like structures. The CNS, in addition to enlarged perivascular lacunes in cerebral white matter with lipid-containing macrophages, showed neuronal lipid storage in thalamus, hypothalamus, hippocampus, brain stem nuclei, spinal motor neurons and Purkinje cell dendrites. Ultrastructurally, lamellated inclusions containing gangliosides were seen in mesenchymal cells, oligodendrocytes, pericytes and Schwann cells. Neurons contained abundant ceroid but no lamellated inclusions. Neurochemistry revealed decrease of alpha-L-iduronidase activity in brain tissue to 4% of normal, normal activities of other lysosomal enzymes, and normal lipid and ganglioside patterns. While the morphology and neurochemistry data are characteristic of mucopolysaccharidosis I, the phenotype of adult alpha-L-iduronidase deficiency mimicking Friedreich's disease has not been described so far.

We have identified a mutation causing beta-glucuronidase (beta Gl) deficiency in a 6-year-old girl with mucopolysaccharidosis type VII. Enzyme assay of lysates of a girl's lymphocytes or cultured fibroblasts showed little residual activity and a normal beta Gl-specific mRNA level, as revealed by Northern-blot analysis. Sequencing of the full-length mutated cDNA revealed a C----T transition, an event causing a single Ala619----Val change (we designated this variant beta GGifu). This change is detected by loss of the cleavage site for the enzyme Fnu4HI in the mutated cDNA. On the basis of the loss of Fnu4HI restriction site, the patient was shown to be a homozygote with the beta GGifu mutation and her parents and brother were heterozygotes. This mutation disrupts a functional domain consisting of a region of sequence highly conserved among human, rat and bacterial beta Gls, and it reduces the enzyme activity, as tested by transfection of COS cells with expression vectors harboring the mutated cDNA.

We recently described a murine model for mucopolysaccharidosis VII in mice that have an inherited deficiency of beta-glucuronidase (beta-D-glucuronoside glucuronosohydrolase, EC 3.2.1.31). Affected mice, of genotype gusmps/gusmps, present clinical manifestations similar to those of humans with mucopolysaccharidosis VII (Sly syndrome) and are shown here to have secondary elevations of other lysosomal enzymes. The mucopolysaccharidosis VII phenotype in both species includes dwarfism, skeletal deformities, and premature death. Lysosome storage is visualized within enlarge vesicles and correlates biochemically with accumulation of undegraded and partially degraded glycosaminoglycans. In this report we describe the consequences of introducing the human beta-glucuronidase gene, GUSB, into gusmps/gusmps mice that produce virtually no murine beta-glucuronidase. Transgenic mice homozygous for the mucopolysaccharidosis VII mutation expressed high levels of human beta-glucuronidase activity in all tissues examined and were phenotypically normal. Biochemically, both the intralysosomal storage of glycosaminoglycans and the secondary elevation of other acid hydrolases were corrected. These findings demonstrate that the GUSB transgene is expressed in gusmps/gusmps mice and that human beta-glucuronidase corrects the murine mucopolysaccharidosis storage disease.

Retroviral vectors were constructed containing a rat beta-glucuronidase cDNA driven by heterologous promoters. Vector-mediated gene transfer into human and canine beta-glucuronidase-deficient mucopolysaccharidosis type VII fibroblasts completely corrected the deficiency in beta-glucuronidase enzymatic activity. In primary cultures of canine mucopolysaccharidosis type VII retinal pigment epithelial cells, which contain large amounts of undegraded glycosaminoglycan substrates, vector correction restored normal processing of specific glycosaminoglycans in the lysosomal compartment. In canine mucopolysaccharidosis type VII bone marrow cells, beta-glucuronidase was expressed at high levels in transduced cells. Thus, the vector-encoded beta-glucuronidase was expressed at therapeutic levels in the appropriate organelle and corrected the metabolic defect in cells exhibiting the characteristic pathology of this lysosomal storage disorder.

Genetic screening should greatly improve the quality of life. A thorough family and medical history is the basis for identifying families at high risk for genetic traits and diseases. Recognition is enhanced by awareness of diseases associated with certain racial, ethnic or geographic groups. Effective genetic screening requires close collaboration between physicians, public health officers and medical investigators.

Serum samples from 175 individuals in six Sanfilippo syndrome type B (SFB) families and 360 White controls were assayed for serum alpha-N-acetyl-D-glucosaminidase (NAG) activity. Only minimal overlap was observed between the controls' NAG activity distribution and that of the 12 obligate heterozygotes. The distribution of NAG activity was log transformed to reduce skewness, and segregation of family members with a prior risk of being a SFB carrier was well within expected limits. However, in one consanguineous family the NAG activity of both parents of one SFB obligate heterozygote was within the normal range for NAG activity. Plausible explanations for this finding are discussed. Additionally, the serum NAG activity of one control and her mother were found to lie within one standard deviation of the obligate heterozygote mean. These individuals are most probably carriers for SFB.

Canine mucopolysaccharidosis type VII results from deficient activity of lysosomal beta-glucuronidase. Residual enzymatic activity (0.2-1.7% of normal) was detected in tissue homogenates from affected dogs. In contrast, serum and urine from affected animals had up to 15% residual activity. To further characterize the nature of the defective enzyme, hepatic beta-glucuronidase was partially purified from normal and MPS VII dogs for determination of their physical and kinetic properties. About 65% of the total beta-glucuronidase in normal canine liver required detergent for solubilization (i.e., membrane-associated), whereas only 22% of the residual activity in canine MPS VII liver was membrane-associated. Compared to the normal hepatic enzyme, the Km towards 4-methylumbelliferyl-beta-glucuronide was markedly increased in MPS VII dogs (i.e., 0.48 versus greater than 2.5 mmol/l). In contrast, the thermo-, cryo-, and pH stability properties, as well as the pH optimum (approximately 4.6), were essentially unaffected. In addition, the canine MPS VII hepatic residual activity was unresponsive to sulfhydryl reducing reagents and divalent cations, despite the fact that incubation of normal canine beta-glucuronidase with dithiothreitol and magnesium and/or calcium enhanced the activity more than 15-fold.

Routine investigations of 1568 children with severe-profound hearing loss, during a 15 years' period, revealed the following classification: Hereditary Deafness 25%, Acquired Deafness 43% (prenatally 11%, perinatally 16%, postnatally 16%), Unknown Deafness 32%. This group of unknown causes is usually large in any surgery of deafness and in many of these children deafness is believed to have a genetic basis. In the light of this premise, we performed more careful genetic and clinical investigation in 268 children coming under observation in the 3 last years. Moreover, we examined a group of 44 asymptomatic parental pairs of these children to determine if any were carriers of genes for deafness. The criteria used for identification were: pure tone audiometry, speech discrimination score, threshold of the acoustic reflex, Lüscher test, loudness discomfort level for 1-2-4 kHz, continuous Bekesy audiometry. Children follow-up enabled us to place 14 cases in the range of hereditary syndromes. Therefore, the group of unknown deafness decreased from 32% to 27%. The audiological investigation, performed on the parental pairs, pointed out an abnormal auditory function in 30.6% of subjects, who for these reasons should be considered as heterozygous carriers.

A new case of multiple sulphatase deficiency with onset at birth is described. The patient had many dysmorphic features and hydrocephalus, similar to one other case with early onset described in the literature. The new patient differed from the other case in having chondrocalcificans congenita, heart abnormalities and an abnormal fold of tissue present between the laryngeal inlet and the oesophagus. Excessive mucopolysacchariduria was present and there was profound deficiency of all sulphatases examined in plasma, leucocytes and cultured skin fibroblasts.

Although five quantitative ultrasonic methods for assessment of liver size in children have been published, there is no account in the literature of experience over the full range of clinical material. This experience, however, is available from our material of 300 cases examined by a roentgenological method, giving a notion of the results to be obtained with a quantitative method in children.

Clinical, radiological and biochemical findings are described in a male newborn with type VII mucopolysaccharidosis (betaglucuronidase deficiency). A metabolic storage disease was likely at birth, because of morphological and radiological features and granulated cells in blood and bone marrow. A study of glycosaminoglycans has been performed in urine and various organs post mortem. Enzymatic deficiency was found in serum, leucocytes, skin fibroblasts, liver, spleen and kidneys. Low activities were present in both parents.

The mucopolysaccharidoses are a group of genetic diseases characterized by storage of incompletely degraded glycosaminoglycans. Such storage causes marked distortion of many tissues with consequent severe somatic changes and mental retardation. Storage of glycosaminoglycans results from markedly diminished activity of specific hydrolases requisite for the normal degradation of glycosaminoglycans. The specific enzymic defects have been identified in nine different diseases. In some cases evidence has been obtained indicating the existence of additional allelic diseases based on the same enzyme. The knowledge obtained from these studies has made prenatal diagnosis possible and has led to the possibility that therapy may be undertaken utilizing enzyme replacement.

The present paper describes 3 out of a total of 9 siblings, aged 9, 17, and 18, with the following symptoms: gargoyle-like facial features, clouding of the cornea in both eyes, dysostosis multiplex, slightly impaired intelligence, hepatosplenomegaly, umbilical hernia, and increased secretion of mucopolysaccharides in the urine, in particular dermatan and heparan sulfate. Some of the symptoms are mid-way between those of Hurler's and Scheie's syndromes, both having the same deficiency of the enzyme alpha-1-iduronidase. McKusik developed the theory that the genes responsible for the clinical pictures of Hurler's and Scheie's syndromes are alleles and hence cases such as those described here should be considered as allelomorphic compounds.

As 40-60% of all heredity disturbances are of genetic origin, it is necessary to apply complex human genetic methods in diagnosis and prevention. Formerly clinicogenetic examinations in most cases only implied the analyses of hereditary constitution. An observation as demonstrated through the examples of several kinships with hereditary disturbances of hearing may serve as a model of complex clinicogenetic investigations. In all cases the diagnosis of hereditary disturbances of hearing must be followed by human genetic family advice.

We present five patients with alpha-L-iduronidase deficiency who do not have the typical Hurler or Scheie phenotypes; they are compared to 28 similarly atypical cases from the literature. Phenotypic differences are pointed out and intrafamilial similarities stressed. Among the various possible explanations for this situation, the existence of genetic compounds seems acceptable for some of the cases, but others seem to be caused by different mutations. The elucidation of these alternative possibilities from recent biochemical research is discussed.