Acute disseminated encephalomyelitis in China, Singapore and Japan: a comparison with the USA.

BACKGROUND AND PURPOSE: Ethnicity-related differences in the incidence of acute disseminated encephalomyelitis (ADEM) and other demyelinating diseases including multiple sclerosis and neuromyelitis optica spectrum disorders have been reported. Little is reported on the influence of ethnicity and geographical location in ADEM. METHODS: Medical records of patients who presented with ADEM (ICD-9 323.61 and 323.81) at large referral hospitals in China, Singapore and Japan (years 1992-2015) were retrospectively reviewed and data were collected in a centralized database. Presenting features and outcomes of ADEM were compared between this multi-country Asian cohort and a uniformly collected US cohort using risk differences and risk ratios. Both cohorts were standardized to a 35% pediatric population to facilitate the comparison. RESULTS: There were 83 Asian patients (48 male, 16 pediatric) followed for a median of 2 (25th-75th percentile 1-10) months. Asian patients exhibited a 26% higher prevalence of spinal cord involvement on magnetic resonance imaging [95% confidence interval (CI) 0-52%; P = 0.05; 63% vs. 37%], a 39% lower prevalence of preceding events (95% CI 12-65%; P < 0.01; 33% vs. 72%) and a 23% lower prevalence of corpus callosum involvement (95% CI 7-39%; P < 0.01; 8% vs. 31%). No difference was observed between the two cohorts in the probability of relapse over the first year after disease onset. CONCLUSIONS: It is hypothesized that the high proportion of Asian patients with spinal cord lesions relates to genetic vulnerability or the higher incidence of neuromyelitis optica spectrum disorders in Asia or could be a spurious association. ADEM presentations most probably vary across geographical settings or ethnicities.

Temporal course of depressive symptoms during the development of Alzheimer disease.

OBJECTIVE: To characterize change in depressive symptoms before and after the onset of dementia in Alzheimer disease (AD). METHOD: We used data from the Chicago Health and Aging Project, a longitudinal cohort study of risk factors for AD in a geographically defined population of old people. Two subsets were analyzed. In 357 individuals who developed incident AD during the study, self-report of depressive symptoms (Center for Epidemiologic Studies Depression Scale) was obtained at 3-year intervals for a mean of 8 to 9 years. In 340 individuals who agreed to annual data collection, informant report of depressive symptoms (Hamilton Depression Rating Scale) was obtained for a mean of 3 years after a diagnosis of AD (n = 107), mild cognitive impairment (n = 81), or no cognitive impairment (n = 152). RESULTS: The incident AD group reported a barely perceptible increase in depressive symptoms during 6 to 7 years of observation before the diagnosis (0.04 symptoms per year) and no change during 2 to 3 years of observation after the diagnosis except for a slight decrease in positive affect. In those with annual follow-up, neither AD nor its precursor, mild cognitive impairment, was associated with change in informant report of depressive symptoms during a mean of 3 years of observation. CONCLUSION: Depressive symptoms show little change during the development and progression of AD to a moderate level of dementia severity.

Clinical, enzymatic and molecular characterization of nine new patients with malonyl-coenzyme A decarboxylase deficiency.

We report nine new patients with malonic aciduria associated with enzyme-confirmed malonyl-CoA decarboxylase (MCD) deficiency in eight. Clinical details were available on eight, and molecular genetic characterization was obtained for nine. As for 15 previously described patients, cardinal clinical manifestations included developmental delay and cardiomyopathy; metabolic perturbations (e.g. acidosis) and seizures, however, were infrequent or not observed in our patients. For all, detection of elevated malonic acid in urine (+/- increased C3DC acylcarnitine by analysis employing tandem mass spectrometry) led to pursuit of enzyme studies. MCD activities (nmol/h PER mg protein) revealed: control (n = 22), 16.2 +/- 1.8 (SEM; range 5.7-46.2); patients (n = 8, assayed in duplicate), 1.7 +/- 0.3 (10% of parallel control; range 0.6-2.8). Molecular characterization by DNA sequence analysis and multiplex ligation-dependent probe amplification revealed nine novel mutations (c.796C>T; p.Gln266X, c.481delC; p.Leu161CysfsX18, c.1367A>C; p.Tyr456Ser, c.1319G>T; p.Ser440Ile, c.1430C>T; p.Ser477Phe, c.899G>T; p.Gly300Val, c.799-1683_949-1293del3128, and two other large genomic deletions comprising exons 1 or the complete gene) and two known mutations in the MLYCD gene. Our findings increase the number of enzyme-confirmed MCD-deficient patients by >50%, and expand our understanding of the phenotypic and molecular heterogeneity of this rare disorder.

Phenylketonuria in adulthood: a collaborative study.

During 1967-1983, the Maternal and Child Health Division of the Public Health Services funded a collaborative study of 211 newborn infants identified on newborn screening as having phenylketonuria (PKU). Subsequently, financial support was provided by the National Institute of Child Health and Human Development (NICHD). The infants were treated with a phenylalanine (Phe)-restricted diet to age 6 years and then randomized either to continue the diet or to discontinue dietary treatment altogether. One hundred and twenty-five of the 211 children were then followed until 10 years of age. In 1998, NICHD scheduled a Consensus Development Conference on Phenylketonuria and initiated a study to follow up the participants from the original Collaborative Study to evaluate their present medical, nutritional, psychological, and socioeconomic status. Fourteen of the original clinics (1967-1983) participated in the Follow-up Study effort. Each clinic director was provided with a list of PKU subjects who had completed the original study (1967-1983), and was asked to evaluate as many as possible using a uniform protocol and data collection forms. In a subset of cases, magnetic resonance imaging and spectroscopy (MRI/MRS) were performed to study brain Phe concentrations. The medical evaluations revealed that the subjects who maintained a phenylalanine-restricted diet reported fewer problems than the diet discontinuers, who had an increased rate of eczema, asthma, mental disorders, headache, hyperactivity and hypoactivity. Psychological data showed that lower intellectual and achievement test scores were associated with dietary discontinuation and with higher childhood and adult blood Phe concentrations. Abnormal MRI results were associated with higher brain Phe concentrations. Early dietary discontinuation for subjects with PKU is associated with poorer outcomes not only in intellectual ability, but also in achievement test scores and increased rates of medical and behavioural problems.

Recombinant human acid alpha-glucosidase enzyme therapy for infantile glycogen storage disease type II: results of a phase I/II clinical trial.

PURPOSE: Infantile glycogen storage disease type II (GSD-II) is a fatal genetic muscle disorder caused by deficiency of acid alpha-glucosidase (GAA). The purpose of this study was to investigate the safety and efficacy of recombinant human GAA (rhGAA) enzyme therapy for this fatal disorder. METHODS: The study was designed as a phase I/II, open-label, single-dose study of rhGAA infused intravenously twice weekly in three infants with infantile GSD-II. rhGAA used in this study was purified from genetically engineered Chinese hamster ovary (CHO) cells overproducing GAA. Adverse effects and efficacy of rhGAA upon cardiac, pulmonary, neurologic, and motor functions were evaluated during 1 year of the trial period. The primary end point assessed was heart failure-free survival at 1 year of age. This was based on historical control data that virtually all patients died of cardiac failure by 1 year of age. RESULTS: The results of more than 250 infusions showed that rhGAA was generally well tolerated. Steady decreases in heart size and maintenance of normal cardiac function for more than 1 year were observed in all three infants. These infants have well passed the critical age of 1 year (currently 16, 18, and 22 months old) and continue to have normal cardiac function. Improvements of skeletal muscle functions were also noted; one patient showed marked improvement and currently has normal muscle tone and strength as well as normal neurologic and Denver developmental evaluations. Muscle biopsies confirmed that dramatic reductions in glycogen accumulation had occurred after rhGAA treatment in this patient. CONCLUSIONS: This phase I/II first study of recombinant human GAA derived from CHO cells showed that rhGAA is capable of improving cardiac and skeletal muscle functions in infantile GSD-II patients. Further study will be needed to assess the overall potential of this therapy.

Canine heparan sulfate sulfamidase and the molecular pathology underlying Sanfilippo syndrome type A in Dachshunds.

Heparan sulfate sulfamidase (HSS) is a lysosomal exohydrolase that, when deficient, results in intralysosomal accumulation of heparan sulfate and the clinical phenotype of Sanfilippo syndrome type A. The first animal disease homolog of human Sanfilippo syndrome type A has been recently indentified in Dachshund littermates. To identify the molecular defect, the nucleotide sequences of the normal canine HSS gene and cDNA were determined using PCR-based approaches. The coding region showed 87% nucleotide homology, and 89% amino acid sequence homology, with human HSS. All exon-intron borders were conserved. Sequence analysis of the entire coding region with exon-intron boundaries was performed in the propositus, a healthy littermate, and six unrelated normal dogs. Comparison revealed a 3-bp deletion, 737-739delCCA, resulting in the loss of threonine at position 246 in both alleles of the propositus and in one allele of a healthy littermate. Prediction of the three-dimensional structure of canine HSS, based on homology with human arylsulfatases A and B, suggested the pathogenic effect of this deletion. Six other sequence variations in exons, and 10 in introns, appear to be benign polymorphisms. This study supports the potential development of a canine model of Sanfilippo syndrome type A to evaluate gene therapy for this disorder.

Estrogens control aggressive behavior in some patients with Sanfilippo syndrome.

We report two women with Sanfilippo syndrome. Both had characteristic aggressiveness that was refractory to treatment with conventional agents. Both women improved on oral estrogen therapy and showed diminished aggressiveness.

Laminin alpha2 muscular dystrophy: genotype/phenotype studies of 22 patients.

OBJECTIVE: To determine the number of primary laminin alpha2 gene mutations and to conduct genotype/phenotype correlation in a cohort of laminin alpha2-deficient congenital muscular dystrophy patients. BACKGROUND: Congenital muscular dystrophies (CMD) are a heterogeneous group of muscle disorders characterized by early onset muscular dystrophy and a variable involvement of the CNS. Laminin alpha2 deficiency has been reported in about 40 to 50% of cases of the occidental, classic type of CMD. Laminin alpha2 is a muscle specific isoform of laminin localized to the basal lamina of muscle fibers, where it is thought to interact with myofiber membrane receptor, such as integrins, and possibly dystrophin-associated glycoproteins. METHODS: Seventy-five CMD patients were tested for laminin alpha2 expression by immunofluorescence and immunoblot. The entire 10 kb laminin alpha2 coding sequence of 22 completely laminin alpha2-deficient patients was screened for causative mutations by reverse transcription (RT)-PCR/single strand conformational polymorphisms (SSCP) analysis and protein truncation test (PTT) analysis followed by automatic sequencing of patient cDNA. Clinical data from the laminin alpha2-deficient patients were collected. RESULTS: Thirty laminin alpha2-negative patients were identified (40% of CMD patients tested) and 22 of them were screened for laminin alpha2 mutations. Clinical features of laminin alpha2-deficient patients were similar, with severe floppiness at birth, delay in achievement of motor milestones, and MRI findings of white matter changes with normal intelligence. Loss-of-function mutations were identified in 95% (21/22) of the patients studied. SSCP analysis detected laminin alpha2 gene mutations in about 50% of the mutant chromosomes; PTT successfully identified 75% of the mutations. A two base pair deletion mutation at position 2,096-2,097 bp was present in 23% of the patients analyzed. CONCLUSIONS: Our data suggest that the large majority of laminin alpha2-deficient patients show laminin alpha2 gene mutations.

Very-long-chain acyl-CoA dehydrogenase subunit assembles to the dimer form on mitochondrial inner membrane.

This paper describes the process of dimer assembly of mitochondrial very-long-chain acyl-CoA dehydrogenase (VLCAD) subunit. Mature VLCAD is a homodimer of a 70-kDa protein associated with the mitochondrial membrane. Newly synthesized VLCAD was present as a monomer and the major fraction was associated with the mitochondrial inner membrane. The association of VLCAD subunit with the mitochondrial membrane was observed early during dimer formation. In contrast, a VLCAD monomeric mutant S583W, a novel mutation identified from a patient with VLCAD deficiency, did not associate with the mitochondrial membrane after import and the major fraction remained in the mitochondrial matrix. These results suggest that association of VLCAD protein with mitochondrial inner membrane is necessary for dimer assembly and formation of mature VLCAD.

Genotype-phenotype correlation for nucleotide substitutions in the IgII-IgIII linker of FGFR2.

Dominantly acting, allelic mutations of the fibroblast growth factor receptor 2 (FGFR2) gene have been described in five craniosynostosis syndromes. In Apert syndrome, characterised by syndactyly of the hands and feet, recurrent mutations of a serine-proline dipeptide (either Ser252Trp or Pro253Arg) in the linker between the IgII and IgIII extracellular immunoglobulin-like domains, have been documented in more than 160 unrelated individuals. We have identified three novel mutations of this dipeptide, associated with distinct phenotypes. A C-->T mutation that predicts a Ser252Leu substitution, ascertained in a boy with mild Crouzon syndrome (craniosynostosis with normal limbs) is also present in three clinically normal members of his family. A CG-->TT mutation that predicts a Ser252Phe substitution results in a phenotype consistent with Apert syndrome. Finally, a CGC-->TCT mutation that predicts a double amino acid substitution (Ser252Phe and Pro253Ser) causes a Pfeiffer syndrome variant with mild craniosynostosis, broad thumbs and big toes, fixed extension of several digits, and only minimal cutaneous syndactyly. The observation that the Ser252Phe mutation causes Apert syndrome, whereas the other single or double substitutions are associated with milder or normal phenotypes, highlights the exquisitely specific molecular pathogenesis of the limb and craniofacial abnormalities associated with Apert syndrome. Ser252Phe is the first noncanonical mutation to be identified in this disorder, its rarity being explained by the requirement for two residues of the serine codon to be mutated. The description of independent, complex nucleotide substitutions involving identical nucleotides is unprecedented, and we speculate that this may result from functional selection of FGFR mutations in sperm.

Fetal hemoglobin expression in transplant recipients of placental blood hematopoietic progenitor cells.

Patients who achieved bone marrow engraftment of cord blood-derived progenitor cells provided an opportunity to examine the expression of fetal Hb by neonatal hematopoietic progenitors in a postneonatal host. Cord blood cells from histocompatible siblings were successfully transplanted in two children with the Fanconi anemia syndrome. One of the transplant donors had heterocellular hereditary persistence of fetal Hb, apparently due to gamma-globin gene triplication; the other donor was hematologically normal. The G gamma/A gamma ratio of the patient who received his transplant from the donor with hereditary persistence of fetal Hb was markedly elevated, similar to that of the transplant donor's cord blood, and this ratio remained elevated in subsequent months. In the other child, the G gamma/A gamma ratio immediately after her transplant was typical of the normal newborn, and over the next several months it reverted to the adult pattern. Globin synthesis studies performed shortly after engraftment demonstrated ratios of fetal Hb/adult Hb synthesis in both patients that were typical of those of normal newborns. Over the next several months, both patients converted to the adult pattern. Fetal Hb to adult Hb switching in these patients seemed to follow a temporal sequence intrinsic to the transplanted neonatal progenitor cells, without discernible influence of postneonatal environmental factors. The program for Hb switching seems to be an inherent feature of neonatal hematopoietic progenitor cells.

Clinical and pathologic findings in 2 siblings with congenital nephrotic syndrome.

We report the clinical and pathologic findings of 2 siblings affected with congenital nephrotic syndrome (CNS). The parents were a nonconsanguineous Mexican couple. The first sibling was born at term and developed proteinuria, hypoproteinemia, edema and ascites by its second month of life; he died septic at 6 months of age. The second sibling was diagnosed with congenital nephrosis during the second trimester of pregnancy. Prenatal demonstration of reno-placentomegaly can help in making the presumptive diagnosis of CNS in patients with high maternal serum and amniotic fluid AFP, normal acetylcholinesterase and normal karyotype. The pathologic findings of the kidneys of these siblings demonstrate that tubular microcysts are not critical to the disease process and are only the manifestation of a progressive disease in which the primary renal defect probably resides in a lack of integrity of the glomerular epithelial cells serving as filter.

Identification of a novel exonic mutation at -13 from 5' splice site causing exon skipping in a girl with mitochondrial acetoacetyl-coenzyme A thiolase deficiency.

We identified a novel exonic mutation which causes exon skipping in the mitochondrial acetoacetyl-CoA thiolase (T2) gene from a girl with T2 deficiency (GK07). GK07 is a compound heterozygote; the maternal allele has a novel G to T transversion at position 1136 causing Gly379 to Val substitution (G379V) of the T2 precursor. In case of in vivo expression analysis, cells transfected with this mutant cDNA showed no evidence of restored T2 activity. The paternal allele was associated with exon 8 skipping at the cDNA level. At the gene level, a C to T transition causing Gln272 to termination codon (Q272STOP) was identified within exon 8, 13 bp from the 5' splice site of intron 8 in the paternal allele. The mRNA with Q272STOP could not be detected in GK07 fibroblasts, presumably because pre-mRNA with Q272STOP was unstable because of the premature termination. In vivo splicing experiments revealed that the exonic mutation caused partial skipping of exon 8. This substitution was thought to alter the secondary structure of T2 pre-mRNA around exon 8 and thus impede normal splicing. The role of exon sequences in the splicing mechanism is indicated by the exon skipping which occurred with an exonic mutation.

Role of tyrosinase as the determinant of pigmentation in cultured human melanocytes.

Variations in human pigmentation among different racial groups are due to differences in the production and deposition of melanin in the skin. Although melanin synthesis is known to be controlled by the rate-limiting enzyme tyrosinase, the role of this enzyme as the principal determinant of skin pigmentation is unclear. Results from studies with human melanocyte cultures derived from different racial skin types reveal an excellent correlation between the melanin content of melanocyte cultures and the in situ activity of tyrosinase. Melanocytes derived from black skin have up to 10 times more tyrosinase activity and produce up to 10 times more melanin than melanocytes derived from white skin. However, the higher level of tyrosinase activity in melanocytes derived from black skin is not due to a greater abundance of tyrosinase. Results from immunotitration experiments and Western immunoblots reveal that the number of tyrosinase molecules present in white-skin melanocytes may equal the number found in highly pigmented black skin types. Moreover, approximately equivalent levels of tyrosinase mRNA are present in white and black skin cell strains. In contrast, melanocytes derived from red-haired neonates with low tyrosinase activity contain low numbers of tyrosinase molecules and low levels of tyrosinase mRNA. These results show that tyrosinase activity and melanin production in most light-skinned people is controlled primarily by a post-translational regulation of pre-existing enzyme and not by regulating tyrosinase gene activity. In contrast, melanocytes from red-haired (type I) people have low levels of tyrosinase protein and mRNA, suggesting that transcriptional activity of the tyrosinase gene is suppressed.

Tentative assignment of gene for oto-palato-digital syndrome to distal Xq (Xq26-q28).

Detailed physical mapping of oto-palato-digital (OPD) syndrome gene on the X-chromosome was attempted on a family of 3 generations with 2 affected men. Although the result remains statistically non-significant, it indicates that the OPD-I gene might be located on the distal Xq.

Cloning and sequencing of the porcine kappa-casein cDNA.

cDNA clones encoding porcine kappa-casein were isolated and sequenced. The porcine kappa-casein cDNA is 851 bp in length and encodes a preprotein of 188 amino acids.

Altered phosphorylation state of branched-chain 2-oxo acid dehydrogenase in a branched-chain acyltransferase deficient human fibroblast cell line.

The abundance and phosphorylation state of the polypeptide constituents of the human branched-chain 2-oxo acid dehydrogenase complex were examined in mitochondria from normal and maple syrup urine disease (MSUD) fibroblasts. In normal fibroblast mitochondria two forms of the E1 alpha subunit were observed: non-phosphorylated (E1 alpha) and phosphorylated (E1 alpha-P). About 40-50% of E1 alpha was present as E1 alpha-P. The ability to quantitate the two forms of E1 alpha permitted examination of the association between decreased capacity of oxidize branched-chain 2-oxo acids and the phosphorylation state of E1 alpha. Changes in phosphorylation state of E1 alpha were observed in MSUD fibroblasts as compared to control cells. Of particular interest was the absence of E1 alpha-P in an MSUD fibroblast line which lacked the dihydrolipoyl acyltransferase (E2) subunit of the dehydrogenase complex. In two MSUD cell lines deficient in E1 alpha, the abundance of E1 alpha-P appeared to be preferentially reduced. A fourth MSUD cell line contained normal quantities of E3, E2 and both forms of the E1 alpha polypeptide. Our results indicate that alterations in the abundance of dehydrogenase complex polypeptides in MSUD fibroblasts may influence the phosphorylation state of the E1 alpha polypeptide. They demonstrate the potential for examining simultaneously mutations which affect both the catalytic and regulatory components of the dehydrogenase complex.