Metachromatic leukodystrophy (MLD) is the rare neurometabolic disease caused by the deficiency of the enzyme arylsulfatase A resulting in a deficiency of sulfatide degradation and the target gene is ARSA gene. We report a case of the late infantile form of MLD that was confirmed by means of enzyme assay and gene analysis with typical brain MRI and MR spectroscopy finding.
Brain ; Cerebroside-Sulfatase ; Enzyme Assays ; Leukodystrophy, Metachromatic ; Magnetic Resonance Spectroscopy ; Molecular Biology

Metachromatic leukodystrophy (MLD) is an autosomal recessive disease caused by a deficiency in arylsulfatase A (ARSA). However, decreased ARSA activity is also observed in pseudodeficiency (PD). To distinguish between MLD and PD, we performed gene mutation and sulfatide analyses by using dried blood spots (DBSs) from seven Korean individuals who underwent an analysis of ARSA activity. DNA was extracted from DBSs, and PCR-direct sequencing of ARSA was performed. The cDNA obtained was analyzed to confirm a novel mutation. Of the seven subjects, three were confirmed as having MLD, one was confirmed as having MLD-PD, one was confirmed as having PD, and the remaining two were obligate heterozygotes. We verified the novel pathogenic variant c.1107+1delG by performing familial and cDNA analyses. Sulfatide concentrations in DBSs were analyzed and were quantified by using ultra-performance liquid chromatography and tandem mass spectrometry, respectively. Total sulfatide concentration was inversely correlated with ARSA activity (Spearman's coefficient of rank correlation, P=0.929, P=0.0025). The results of this mutational and biochemical study on MLD will increase our understanding of the genetic characteristics of MLD in Koreans.
Cerebroside-Sulfatase ; Chromatography, Liquid ; DNA ; DNA, Complementary ; Heterozygote ; Leukodystrophy, Metachromatic* ; Tandem Mass Spectrometry

OBJECTIVE: To explore the genetic basis for a child with metachromatic leukodystrophy (MLD). METHODS: Clinical data of the patient was collected. Genomic DNA was extracted from peripheral blood samples of the child and his family members. Potential variant was screened by whole exome sequencing (WES), and candidate variant was verified by Sanger sequencing. The pathogenicity the variant was analyzed by multiple sequence alignment of the amino acid sequence and three-dimensional model prediction of its protein product. RESULTS: The child was found to harbor compound heterozygous variants c.257G>A (p.R86Q) and c.467del (p.G156Afs*6) of the ARSA gene, among which the c.467del (p.G156Afs*6) frameshift variation was unreported previously. Multiple sequence alignment showed that the site of the c.257G>A (p.R86Q) missense variant is highly conserved. Three-dimensional structure modeling analysis showed that the partial deletion due to the p.G156Afs*6 variant may cause significant alteration of the structure of ARSA protein. CONCLUSION The discovery of novel variant in ARSA has enriched the mutational spectrum of MLD and may facilitate the understanding of the genotype-phenotype correlation of MLD.
Cerebroside-Sulfatase/genetics* ; DNA ; Genetic Association Studies ; Humans ; Leukodystrophy, Metachromatic/genetics* ; Mutation

The deletion 22q13 syndrome (Phelan-McDermid syndrome) is a rare microdeletion syndrome characterized by prominent neurobehavioral deficits including neonatal hypotonia, developmental delay, language delay, autism, and minor dysmorphic features. Due to nonspecific facial features and difficulties in detection in routine chromosome analysis, this chromosome deletion syndrome has gone under-diagnosed. Fluorescence in situ hybridization (FISH) is required to confirm the presence of this deletion. Here we report the first case of 22q13 deletion syndrome in Korea. An 18-month-old girl was admitted to a pediatric clinic due to severe developmental delay and hypotonia from the neonatal period. She was diagnosed as 22q13 deletion syndrome through a chromosomal analysis and FISH using arylsulfatase A probe.
Autistic Disorder ; Cerebroside-Sulfatase ; Chromosome Deletion ; Developmental Disabilities ; Fluorescence ; Humans ; In Situ Hybridization ; Infant ; Korea ; Language Development Disorders ; Muscle Hypotonia

Metachromatic leukodystrophy is an inherited lysosomal storage disorder caused by the deficiency of arylsulfatase A activity. The patient in this study, a 5-yr-old girl, presented with progressive psychomotor regression. An MRI image of her brain showed bilateral symmetrical demyelination. The arylsulfatase A activity in her leukocytes was decreased to 8.0 nmol/hr/mg protein (reference range, 25-80 nmol/hr/mg protein). Mutation analysis of ARSA, using PCR and direct sequencing, showed two heterozygote pathogenic variations of c.449C>T (p.Pro150Leu) and c.640G>A (p.Ala214Thr). In summary, we report a Korean patient with an early juvenile form of metachromatic leukodystrophy, who was diagnosed based on her clinical symptoms as well as by using biochemical, radiological, and molecular genetic investigations.
Brain ; Cerebroside-Sulfatase ; Demyelinating Diseases ; Female ; Heterozygote ; Humans ; Leukocytes ; Leukodystrophy, Metachromatic* ; Magnetic Resonance Imaging ; Molecular Biology* ; Polymerase Chain Reaction

Metachromatic leukodystrophy (MLD; MIM 250100), a severe neurodegenerative disorder inherited as an autosomal recessive trait, is caused by mutations in the arylsulfatase A (ARSA) gene. Although several germ line ARSA mutations have been identified in patients with MLD of various ethnic backgrounds elsewhere in the world, no genetically confirmed cases of MLD have been reported in Korea. Recently, we identified a mutation in the ARSA gene of a Korean male with MLD. A male infant with late-infantile form of MLD had been admitted to our hospital for further examination. His neuromuscular symptoms, which included inability to walk at the age of 12 months, gradually worsened, even after allograft bone marrow transplantation; he died at the age of 9 yr. His elder brother had also been diagnosed with MLD. To confirm the presence of a genetic abnormality, all the coding exons of the ARSA gene and the flanking introns were amplified by PCR. A molecular analysis of the ARSA gene revealed both a novel heterozygous splicing mutation (c.1101+1G>T) in intron 6 and a heterozygous missense mutation in exon 2 (c.296G>A; Gly99Asp). The patient's elder brother who had MLD is believed to have had the same mutation, which may be correlated with a rapidly deteriorating clinical course. This study identified a novel mutation in the ARSA gene, related to a late-infantile form of MLD with a lethal clinical course and suggested that molecular diagnosis of patients may be useful in early diagnosis and for deciding intervention measures for their family members.
Cerebroside-Sulfatase/*genetics ; Exons ; Heterozygote ; Humans ; Infant ; Introns ; Leukodystrophy, Metachromatic/diagnosis/*genetics ; Magnetic Resonance Imaging ; Male ; *Mutation ; Mutation, Missense ; *RNA Splicing ; RNA, Messenger/genetics

Adult-onset metachromatic leukodystrophy (MLD) is very rare with a combination of cognitive and behavioral symptoms and peripheral polyneuropathy. A 47-year-old man was admitted due to memory impairment, gait disturbance, dysarthria and personality changes for a period of 3 years. The arylsulfatase A level in his leukocytes was decreased. A brain MRI showed bilateral symmetrical demyelination but nerve conduction velocities (NCV) were normal. We report a very rare case of adult-onset MLD with normal NCV.
Behavioral Symptoms ; Brain ; Cerebroside-Sulfatase ; Demyelinating Diseases ; Dysarthria ; Gait ; Humans ; Leukocytes ; Leukodystrophy, Metachromatic* ; Magnetic Resonance Imaging ; Memory ; Middle Aged ; Neural Conduction* ; Polyneuropathies

OBJECTIVETo identify arylsulftase A gene (ARSA) mutations in a Chinese family with MLD.

METHODSThere were two MLD patients in the investigated family. The proband, an 11-year-old girl, was well until the age of 5 years, when she began to experience difficult walking and mental regression. Magnetic resonance imaging (MRI) of her brain showed widespread demyelination, nerve conduction velocity reduced, and ASA activity measured in white blood cells was zero. So, the child was diagnosed having MLD. The proband's young brother also got the same phenotype except clinical symptom being milder than hers. Their parents and elder sister all had normal phenotypes. Genomic DNA samples were extracted from peripheral bloods of the proband and all her family members. All 8 exons and exon-intron boundaries of ARSA gene were amplified by polymerase chain reaction (PCR) and followed by direct DNA sequencing.

RESULTSTwo heterozygous mutations of ARSA, which were named as, G251A (R84Q) and G296T (G99V) were identified in the proband. The two mutations were located in exon 2. The same genotype was found in the proband's young brother, but these mutations were not detected in proband's elder sister. The proband's mother had the heterozygous mutations G296T (G99V), and her father had the heterozygous mutation G251A (R84Q).

CONCLUSIONThese two MLD patients are with both compound heterozygous mutations, which mean one allele with the G296T (G99V) mutation was from their mother, and the other allele with the G251A (R84Q) mutation got from their father. The parents are both carrier with normal phenotype.

Alleles ; Base Sequence ; Cerebroside-Sulfatase ; genetics ; Child ; China ; DNA Mutational Analysis ; Family Health ; Female ; Genotype ; Heterozygote ; Humans ; Leukodystrophy, Metachromatic ; genetics ; pathology ; Magnetic Resonance Imaging ; Male ; Mutation ; Pedigree

No abstract available.
Adult ; Cerebroside-Sulfatase/*metabolism ; Child, Preschool ; *Chromatography, High Pressure Liquid ; Enzyme Assays/instrumentation/*methods ; Female ; Humans ; Kinetics ; Leukocytes/*enzymology ; Leukodystrophy, Metachromatic/diagnosis/enzymology ; Male ; Middle Aged ; Reference Standards ; Substrate Specificity ; Sulfoglycosphingolipids/analysis/metabolism/standards ; *Tandem Mass Spectrometry/standards

We performed a biochemical study on the patient with mucolipidosis III (ML-III, pseudo-Hurler polydystrophy) in Korea. Confluent fibroblasts from the patient and from normal controls were cultured for 4, 12, 24, 48, and 72 hr, respectively. Lysosomal enzyme activities in culture media after different incubation times and in plasma, leukocytes, and fibroblasts were determined. Most of the leukocyte lysosomal enzymes were within normal limits or slightly lowered; however, plasma lysosomal enzyme activities such as those of hexosaminidase and arylsulfatase A were markedly increased. Numerous phase-dense inclusions were present in the cytoplasm of cultured fibroblasts. Lysosomal enzyme activities of fibroblasts were markedly decreased except for beta-glucosidase. The rates of increase of the lysosomal enzyme activities with incubation time were greater in the culture medium of the patient than in normal control, whereas no difference in the beta-glucosidase activity of the culture media of the patient and the control was found. This study describes the first case of ML-III in Korea, with its typical biochemical characteristics, i.e., a problem with targeting and transporting of lysosomal enzymes which results in a marked increase in plasma lysosomal enzyme activities and a high ratio of extracellular to intracellular lysosomal enzyme activities in cultured fibroblasts.
Cerebroside-Sulfatase/blood ; Child, Preschool ; Culture Media/metabolism ; Cytoplasm/metabolism ; Female ; Fibroblasts/metabolism ; Human ; Korea ; Lysosomes/metabolism ; Microscopy, Phase-Contrast ; Mucolipidoses/*metabolism ; Support, Non-U.S. Gov't ; Time Factors ; beta-Glucosidase/metabolism ; beta-N-Acetylhexosaminidase/blood