High-risk screening for Anderson-Fabry disease in patients with cardiac, renal, or neurological manifestations.

Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disorder caused by abnormalities in the α-galactosidase (Gal) A gene (GLA; MIM:300644). The reduced activity of the lysosomal enzyme, α-galactosidase A (α-Gal A) leads to classic early manifestations and vascular disease of the heart, kidneys, and brain. As a high-risk screening for symptomatic AFD using an enzymatic assay on dried blood spot samples, we enrolled 2325 individuals (803 females and 1522 males; median age: 66 years) with cardiac, renal, or neurological manifestations that met at least one of the following criteria: (a) family history of early-onset cardiovascular diseases; (b) typical classic manifestations, such as acroparesthesias, clustered angiokeratoma, cornea verticillata, and hypo-anhidrosis; (c) proteinuria; (d) receiving dialysis; (e) left ventricular hypertrophy on electrocardiography or echocardiography; or (f) history of stroke. Ninety-two patients displayed low α-Gal A activity. Four males and two females had different pathogenic GLA mutations (0.26%) including a novel mutation c.908-928del21. Four males (0.17%) harbored the GLA c.196G>C (p.E66Q) variant. This simple screening protocol using dried blood spot samples is useful for early diagnosis of AFD in high-risk and underdiagnosed patients suffering from various cardiac, renal, or neurological manifestations.

Newborn screening for Pompe disease in Japan: report and literature review of mutations in the GAA gene in Japanese and Asian patients.

A newborn screening program for Pompe disease using dried blood spots (DBSs) was initiated in Japan. Here, we summarized this screening program and described the results of the GAA gene analysis. From April 2013 to November 2016, 103,204 newborns were screened; 71 had low acid alpha-glucosidase (AαGlu) activity. GAA sequencing showed that 32 (45.1%) and 37 (52.1%) of these newborns were homozygous and heterozygous for pseudodeficiency alleles c.[1726G>A; 2965G>A], respectively. Moreover, 24 of 32 newborns with homozygous c.[1726G>A; 2965G>A] alleles had no mutations, and the other eight had one mutation each. Thirty-five of 37 newborns with heterozygous c.[1726G>A; 2965G>A] alleles had one mutation, and the other two had two mutations each. Only one newborn who had two mutations did not harbor c.[1726G>A; 2965G>A] alleles. Thus, it was difficult to distinguish newborns with c.[1726G>A; 2965G>A] alleles from newborns with pre-symptomatic Pompe disease using AαGlu assays in DBSs or fibroblasts; GAA gene sequencing was necessary. Seventy-one newborns had 50 variants, including 21 mutations or predictably pathogenic variants, and 29 polymorphisms or predictably non-pathogenic variants. Four of 21 mutations or predictably pathogenic variants and four of 29 polymorphisms or predictably non-pathogenic variants were novel. No infantile-onset Pompe disease was detected, and three newborns were diagnosed with potential late-onset Pompe disease. In the literature, 156 variants have been reported for 296 patients from 277 families in 41 articles from Japan, Korea, Taiwan, and China. Our results provide insights into GAA gene mutation profiles and the relationship between GAA and Pompe disease in Asian populations.

Unexpectedly High Prevalence of Coronary Spastic Angina in Patients With Anderson-Fabry Disease.

BACKGROUND: Although we and others have reported cases of patients with Anderson-Fabry disease (AFD) complicated by coronary spastic angina (CSA), the prevalence of CSA in these patients remains unknown. Methods and Results: We performed the acetylcholine-induced provocation test, according to the Japanese guidelines for the diagnosis and treatment of patients with CSA, in 9 consecutive patients having 5 independent AFD pedigrees. Coronary spasms were provoked in conjunction with symptoms and ECG ischemic changes in 8 of 9 (89%) patients with AFD. CONCLUSIONS: We found an unexpectedly high prevalence of CSA in patients with AFD.

High-risk screening for Gaucher disease in patients with neurological symptoms.

Gaucher disease (GD) is an autosomal recessive lysosomal storage disorder caused by the deficiency of glucocerebrosidase enzyme activity. Clinical phenotypes of GD are categorized into three groups: (i) non-neuronopathic GD (type 1), (ii) acute neuronopathic GD (type 2) and (iii) subacute neuronopathic GD (type 3). The high-risk screening of neuronopathic GD has been performed using an enzymatic assay on the dried blood spot (DBS) samples. We enrolled a total of 102 individuals (47 females, 55 males; 0-57 years old; median age 10.5 years) with various neurological symptoms. We detected two patients with very low enzyme activity and they were diagnosed with the disease by using glucocerebrosidase gene analysis. Patient 1 was found to be compound heterozygous for the p.R159W/p.R170C locus and patient 2 was found to harbor two mutations at the IVS7+1G>T (c.999+1G>T) and p.L483P sites. This simple screening protocol using DBS samples is useful for early diagnosis of GD in high-risk and underdiagnosed patients suffering from various neurological symptoms.

Plasma exchange and chelator therapy rescues acute liver failure in Wilson disease without liver transplantation.

AIM: Wilson disease (WD) in patients with a New Wilson Index (NWI) score ≥ 11 is fatal, and these patients are good candidates for liver transplantation (LT). However, plasma exchange and chelator therapy are indispensable and effective even for WD with a score ≥ 11. Moreover, continuous hemodiafiltration (CHDF) with these treatments is essential for acute liver failure (ALF) in WD with hepatic encephalopathy because CHDF can exclude toxic metabolites that may cause damage to the brain. Here, we describe four rescued patients presenting with ALF in WD and discuss the available treatment options. METHODS: We have experienced 11 male and 8 female patients presenting with WD at the Department of Pediatrics, Kumamoto University Hospital between 1999 and 2014. A male and 4 female patients were diagnosed as WD with ALF using a combination of clinical findings and biochemical tests. RESULTS: The NWI score was ≥ 11 in cases 1 to 3. Cases 1 and 2 with hepatic encephalopathy received plasma exchange, CHDF, coagulation factor replacement treatment (CFRT) and LT. Cases 3 and 4 without encephalopathy obtained stable status without LT by plasma exchange, blood infusion, and CFRT. CONCLUSIONS: It is better to undergo LT for WD patients with a NWI score ≥ 11, however, there is a possibility of remission by plasma exchange and medical therapy even without LT. WD patients with a NWI score ≥ 11can be rescued by conservative therapy when the ALF of WD does not present with ALF and hepatic encephalopathy. Therefore, ALF with hepatic encephalopathy itself is an indication for LT in WD.

Liver transplantation may prevent neurodevelopmental deterioration in high-risk patients with urea cycle disorders.

UCDs are among the most common inherited metabolic diseases in Japan. We investigated the clinical manifestations, treatment, and prognoses of 177 patients with UCDs who were evaluated and treated from January 1999 to March 2009 in Japan, using a questionnaire survey. Among these 177 patients, 42 (seven with carbamoyl phosphate synthetase 1 deficiency, 27 with ornithine transcarbamylase deficiency, seven with argininosuccinate synthetase deficiency, and one with arginase 1 deficiency) underwent living-donor LT. Although this study was retrospective and included limited neurodevelopmental information before and after LT, we evaluated whether LT could improve neurodevelopmental outcomes in patients with UCDs. The neurodevelopmental outcomes of patients with a MAC of <300 µmol/L at the time of onset were not significantly different between the LT and non-LT groups (P=.222). LT may have prevented further neurodevelopmental complications in children with MAC ≥300 µmol/L (P=.008) compared with non-transplant management. Therefore, Liver transplant should be considered in patients with UCD with a MAC of ≥300 µmol/L at the time of disease onset.

Amelioration by glycine of brain damage in neonatal rat brain following hypoxia-ischemia.

BACKGROUND: Glycine protected adult brains against injury in an experimental model of stroke, but, because the ischemic response of neonatal brains differs from that of adult brains, we examined the neuroprotective efficacy of glycine and associated mechanisms in an experimental model of neonatal hypoxic-ischemic (HI) encephalopathy. METHODS: Neonatal (postnatal day 7) Wistar rats were randomly divided into an untreated group (non-HI) and two HI groups that were treated with left common carotid artery ligation and saline control or glycine. After recovery, pups that received surgery were injected i.p. with saline or glycine (800 mg/kg; optimal dose determined in pilot experiments) and were placed in a controlled 8% O2 chamber for 120 min. Brains were harvested at various times after return to normoxia (several hours-days after HI) for analysis of infarct area, glial activation, cell apoptosis, and tumor necrosis factor-α (TNF-α) expression on histology and reverse transcription-polymerase chain reaction. RESULTS: Glycine injections induced large (approx. 15-fold) but brief (approx. 2 h) increases in cerebrospinal fluid concentrations. In particular, the glycine group had a >70% decrease in infarct areas compared with controls at 7 days after HI. Glycine also significantly reduced astrocyte reactive transformation, microglia activation, and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive (apoptotic) cell numbers in peri-lesional areas at 3 days after HI, and TNF-α mRNA expression in the injured hemisphere at 12 and 24 h after HI. CONCLUSION: Glycine protected neonatal rat brains against HI, in part by inhibiting TNF-α-induced inflammation and gliosis. Hence, systemic glycine infusions may have clinical utility for the treatment of HI injury in human newborns.

Prenatal diagnosis of Gaucher disease using next-generation sequencing.

In the prenatal diagnosis of Gaucher disease (GD), glucocerebrosidase (GBA) activity is measured with fetal cells, and gene analysis is performed when pathogenic mutations in GBA are identified in advance. Herein is described prenatal diagnosis in a family in which two children had GD. Although prior genetic information for this GD family was not obtained, next-generation sequencing (NGS) was carried out for this family because immediate prenatal diagnosis was necessary. Three mutations were identified in this GD family. The father had one mutation in intron 3 (IVS2 + 1), the mother had two mutations in exons 3 (I[-20]V) and 5 (M85T), and child 1 had all three of these mutations; child 3 had none of these mutations. On NGS the present fetus (child 3) was not a carrier of GD-related mutations. NGS may facilitate early detection and treatment before disease onset.

Mitochondrial DNA depletion syndrome with a mutation in SLC25A4 developing epileptic encephalopathy: A case report.

INTRODUCTION: Autosomal dominant mitochondrial DNA depletion syndrome (MTDPS-12A) is characterized by severe hypotonia from birth due to a mutation in the adenine nucleotide translocator 1 (ANT1). CASE REPORT: A 4-year-old female patient diagnosed with neonatal-onset mitochondrial disease, who had good cognitive function while receiving antiepileptic treatment, presented with sudden-onset status epilepticus with facial and limb myoclonus persisting for more than 30 min. Subsequently, she developed epileptic encephalopathy. Brain MRI showed progressive ventricular enlargement and marked white matter atrophy. She was unable to perform verbal communication or make eye contact and fingertip movements. She lacked any signs of cardiomyopathy. Sanger sequencing demonstrated a heterozygous de novo mutation of c.239G>A (p.Arg80His) in SLC25A4. Her right quadriceps muscle tissue showed lowered complexes I, III, and IV activities and mitochondria DNA depletion (mitochondria/nuclear DNA: 14.6 ± 2.2%) through the quantitative polymerase chain reaction. She was definitively diagnosed with MTDPS-12A. CONCLUSION: Status epilepticus causes encephalopathy in patients with MTDPS-12A. Reducing the energy requirement on the cardiac muscle and brain may be a treatment strategy for patients with MTDPS-12A. Therefore, seizure management and preventive treatment of status epilepticus are considered to be important for maintaining neurodevelopmental outcomes.

Characteristics of Neurological Symptoms in Adult Japanese Patients with Fabry Disease.

Objective Fabry disease (FD) is a hereditary lysosomal storage disease that has been highlighted as a possible etiology of stroke at a young age and presents with other various neurological symptoms. Since FD is rare, limited information is currently available on the prevalence of neurological symptoms in Japanese patients with FD. Therefore, we examined the characteristics of neurological symptoms and brain magnetic resonance imaging (MRI) findings in adult Japanese patients with FD. Methods This was a retrospective, single-center study. We reviewed neurological symptoms and brain MRI findings in the medical records of 12 adult Japanese patients with FD diagnosed by a gene analysis of the α-galactosidase gene. Results Ten out of 12 patients with FD presented with the following neurological symptoms: acroparesthesia (n=6), headache (n=5) [migraine (n=4)], hypohidrosis (n=5), and cerebral infarction (n=3). Two and three of the patients with migraine were complicated by ischemic stroke and coronary spastic angina, respectively. Five and 10 patients presented with periventricular hyperintensity and deep white matter hyperintensity, respectively, on brain MRI. Two out of eight patients had cerebral microbleeds. Seven out of 11 patients had a dilated basilar artery diameter on magnetic resonance angiography. There were no patients with the pulvinar hyperintensity sign. Conclusion Patients with FD present with various neurological symptoms. Headache, particularly migraine, might be a major neurological symptom in patients with FD. Since migraine, ischemic stroke, and coronary spastic angina might occur together in FD, caution is needed when administering triptan to FD patients with migraine.

Current status of newborn screening for Pompe disease in Japan.

BACKGROUND: Pompe disease is an autosomal recessive inherited metabolic disorder caused by a deficiency of the acid α-glucosidase (GAA). Pompe disease manifests as an accumulation of lysosomal glycogen in the skeletal and heart muscle. We conducted newborn screening (NBS) for Pompe disease in Japan from April 2013 to October 2020 to determine the feasibility and utility of NBS for Pompe disease. RESULTS: From the 296,759 newborns whose enzyme activity was measured, 107 of which underwent GAA analysis, we found one patient with infantile-onset Pompe disease (IOPD) and seven with potential late-onset Pompe disease (LOPD). We identified 34 pseudodeficient individuals and 65 carriers or potential carriers. The frequency of patients with IOPD was similar to that in the United States, but significantly lower than that in Taiwan. One patient with IOPD underwent early enzyme replacement therapy within a month after birth before presenting exacerbated manifestations, whereas those with potential LOPD showed no manifestations during the follow-up period of six years. CONCLUSIONS: The frequency of IOPD in Japan was similar to that in the United States, where NBS for Pompe disease is recommended. This indicates that NBS for Pompe disease may also be useful in Japan. Therefore, it should be used over a wider region in Japan.

Adrenocorticotropic Hormone Therapy Improved Spasms and Sleep Disturbance in Smith-Magenis Syndrome: A Case Report.

Smith-Magenis syndrome (SMS) is a complex disorder characterized by variable mental retardation, sleep disturbances, craniofacial and skeletal anomalies, self-injurious and attention-seeking behaviors, and speech and motor delays. The case of a 14-month-old girl with SMS who was experiencing spasm clusters and sleep disturbances with sleep-wake intervals of 1.5 to 2 h persisting from the neonatal period was examined. The patient's spasms stopped and interictal electroencephalography did not show epileptic discharges after undergoing a high-dose adrenocorticotropic hormone (ACTH) therapy. Moreover, the patient's sleep cycle stabilized 1 month after receiving the ACTH therapy. Dramatic reductions in the patient's self-injurious behaviors were also noted. At 1 year following ACTH treatment, the patient's improved sleep was maintained. High-dose ACTH treatment was considered to contribute to the normal adaptation of the hypothalamic-pituitary-adrenal axis by regulating the release of corticotropin-releasing hormone, resulting in improvement of the patient's infantile spasms and sleep disturbances.

Effect of Flunarizine on Alternating Hemiplegia of Childhood in a Patient with the p.E815K Mutation in ATP1A3: A Case Report.

Alternating hemiplegia of childhood (AHC) (MIM 104290) is characterized by transient repeated attacks of paresis on either or both sides of the body, oculomotor and autonomic abnormalities, movement disorders, and cognitive impairment. Preventing paroxysmal attacks, such as paresis and spasm, in patients with AHC is often difficult. An 8-month-old girl presented to our institution with intractable epilepsy. She developed AHC, with left-right alternating or bilateral recurrent plegia upon waking, involuntary movements, eye movement abnormalities, and psychomotor retardation. She had a heterozygous de novo p.E815K mutation in the ATP1A3gene. Patients with this mutation develop severe hemiplegic spells and convulsions, have a poor neuromotor developmental outcome, and are particularly difficult to treat. Flunarizine treatment has limited therapeutic effect in such patients; however, it was definitely effective for bulbar palsy in the present case. The present case further highlights the need for the development of other new treatments, such as a ketogenic diet.

Fabry disease screening in high-risk populations in Japan: a nationwide study.

BACKGROUND: Fabry disease (FD) is a X-linked inherited disorder caused by mutations in the GLA gene, which results in the deficiency of α-galactosidase A (α-Gal A). This leads to the progressive accumulation of metabolites, which can cause multisystemic dysfunction. A recent screening study among neonates reported an increase in the incidence of FD, and numerous FD patients remain undiagnosed or even misdiagnosed. Therefore, this study aimed to identify patients with FD by performing high-risk screening in 18,135 individuals, enrolled from October 2006 to March 2019, with renal, cardiac, or neurological manifestations from all prefectures in Japan. A total of 601 hospitals participated in this study. RESULTS: Low α-Gal A activity was detected in 846 individuals, with 224 of them diagnosed with FD by GLA sequencing. Cases with a family history of FD (n = 64) were also subjected to sequencing, without α-Gal A assay, as per individual request, and 12 of them were diagnosed with a variant of FD. A total of 236 patients with FD (97 males and 139 females) were identified from among 18,199 participants. A total of 101 GLA variants, including 26 novel variants, were detected in the 236 patients with FD from 143 families, with 39 amenable variants (39%) and 79 of the 236 patients (33%) suitable for migalastat treatment. CONCLUSIONS: From among 18,199 participants, 101 GLA variants, including 26 novel variants, were identified in the 236 patients with FD from 143 families. Migalastat was identified as a suitable treatment option in 33% of the patients with FD and 39% of the GLA variants were detected as amenable. Therefore, the simple screening protocol using dried blood spots that was performed in this study could be useful for early diagnosis and selection of appropriate treatments for FD in high-risk and underdiagnosed patients with various renal, cardiac, or neurological manifestations.

Newborn screening for Fabry disease in the western region of Japan.

Newborn screening (NBS) for Fabry disease (FD) is the best way to detect FD early prior to presentation of symptoms and is currently implemented in Taiwan and several states such as Illinois, Missouri, and Tennessee in the United States of America. In this report, we provide data from the first large-scale NBS program for FD in Japan. From August 2006 to December 2018, 599,711 newborns were screened; 26 variants, including 15 pathogenic variants and 11 variants of uncertain significance (VOUS; including eight novel variants), were detected in 57 newborns. Twenty-six male and 11 female newborns with pathogenic variants were diagnosed as hemizygous and heterozygous patients, respectively. Thirteen male and seven female newborns with VOUS were diagnosed as potential hemizygous and potential heterozygous patients, respectively. At the most recent follow up, three of 26 hemizygous patients had manifested symptoms and were receiving enzyme replacement therapy. The other patients were being followed up by clinicians. The frequency of FD (pathogenic variants + VOUS) in this study was estimated to be 1:7683, whereas that of patients with pathogenic variants was 1:11,854. In the future, the NBS system for FD may contribute to the detection of newborns not presenting manifestations related to FD and adults who have or have not developed manifestations related to FD.

The Effect of S-Adenosylmethionine Treatment on Neurobehavioral Phenotypes in Lesch-Nyhan Disease: A Case Report.

Lesch-Nyhan disease (LND) is an X-linked recessive disorder caused by a deficiency in hypoxanthine-guanine phosphoribosyl transferase. Patients with LND experience involuntary movements, including dystonia, choreoathetosis, opisthotonos, ballismus, and self-injury. Alleviating these involuntary movements is important to improve the quality of life in patients with LND. Many clinicians have difficulty controlling these involuntary movements in their patients, and there are no established and effective treatments. A 6-month-old boy with LND presented with generalized dystonia and self-injury behavior that was alleviated after receiving S-adenosylmethionine (SAMe). His self-injury behavior completely resolved after he received SAMe and risperidone. Although he had often experienced inspiratory stridor because of laryngeal dystonia and frequently developed aspiration pneumonitis and bronchitis, no inspiratory stridor was noted after SAMe treatment. The patient is continuing to receive SAMe and risperidone. SAMe treatment alleviates dystonic movements and improves quality of life in pediatric patients with LND. Additional research is needed to determine the long-term safety and efficacy of SAMe and its appropriate dosage.

Natural histories of patients with Wolf-Hirschhorn syndrome derived from variable chromosomal abnormalities.

Wolf-Hirschhorn syndrome (WHS) is a subtelomeric deletion syndrome affecting the short arm of chromosome 4. The main clinical features are a typical craniofacial appearance, growth deficiency, developmental delays, and seizures. Previous genotype-phenotype correlation analyses showed some candidate regions for each clinical finding. The WHS critical region has been narrowed into the region 2 Mb from the telomere, which includes LETM1 and WHSC1; however, this region is insufficient to cause "typical WHS facial appearance". In this study, we identified 10 patients with a deletion involving 4p16.3. Five patients showed pure terminal deletions and three showed unbalanced translocations. The remaining patients showed an interstitial deletion and a suspected inverted-duplication-deletion. Among 10 patients, one patient did not show "typical WHS facial appearance" although his interstitial deletion included LETM1 and WHSC1. On the other hand, another patient exhibited "typical WHS facial appearance" although her small deletion did not include LETM1 and WHSC1. Instead, FGFRL1 was considered as the candidate for this finding. The largest deletion of 34.7 Mb was identified in a patient with the most severe phenotype of WHS.

Neonatal methionine adenosyltransferase I/III deficiency with abnormal signal intensity in the central tegmental tract.

Methionine adenosyltransferase I/III (MAT I/III) deficiency is characterized by persistent hypermethioninemia. The clinical manifestations in cases with MAT I/III deficiency vary from a complete lack of symptoms to neurological problems associated with brain demyelination. We experienced a neonatal case with MAT I/III deficiency, in which severe hypermethioninemia was detected during the newborn screening test. The patient gradually showed hyperreflexia, foot clonus, and irritability from the age of 1 month onwards, and his brain magnetic resonance imaging scans showed abnormal signal intensity in the bilateral central tegmental tracts. His neurological manifestations improved after the S-adenosylmethionine (SAMe) treatment, deteriorated after discontinuation of SAMe, and re-improved owing to re-administration of SAMe. He achieved normal neurodevelopment through SAMe and methionine restriction therapy. Lack of SAMe as well as severe hypermethioninemia were thought to contribute towards the clinical psychophysical state. Moreover, impaired MAT I/III activity contributed to the development of neurological disorder from the early neonatal period.

Genomic backgrounds of Japanese patients with undiagnosed neurodevelopmental disorders.

BACKGROUND: Recently, many genes related to neurodevelopmental disorders have been identified by high-throughput genomic analysis; however, a comprehensive understanding of the mechanism underlying neurodevelopmental disorders remains to be established. To further understand these underlying mechanisms, we performed a comprehensive genomic analysis of patients with undiagnosed neurodevelopmental disorders. METHODS: Genomic analysis using next-generation sequencing with a targeted panel was performed for a total of 133 Japanese patients (male/female, 81/52) with previously undiagnosed neurodevelopmental disorders, including developmental delay (DD), intellectual disability (ID), autism spectrum disorder (ASD), and epilepsy. Genomic copy numbers were also analyzed using the eXome Hidden Markov Model (XHMM). RESULTS: Thirty-nine patients (29.3%) exhibited pathogenic or likely pathogenic findings with single-gene variants or chromosomal aberrations. Among them, 20 patients were presented here. Pathogenic or likely pathogenic variants were identified in 18 genes, including ACTG1, CACNA1A, CHD2, CDKL5, DNMT3A, EHMT1, GABRB3, GABRG2, GRIN2B, KCNQ3, KDM5C, MED13L, SCN2A, SHANK3, SMARCA2, STXBP1, SYNGAP1, and TBL1XR1. CONCLUSION: A diagnostic yield of 29.3% in this study was nearly the same as that previously reported from other countries. Thus, we suggest that there is no difference in genomic backgrounds in Japanese patients with undiagnosed neurodevelopmental disabilities. Although most of the patients possessed de novo variants, one of the patients showed an X-linked inheritance pattern. As X-linked recessive disorders exhibit the possibility of recurrent occurrence in the family, comprehensive molecular diagnosis is important for genetic counseling.