Keiko Ishigaki

Identification of Severe Combined Immunodeficiency by T-Cell Receptor Excision Circles Quantification Using Neonatal Guthrie Cards

OBJECTIVEnTo assess the feasibility of T-cell receptor excision circles (TRECs) quantification for neonatal mass screening of severe combined immunodeficiency (SCID).nnnSTUDY DESIGNnReal-time PCR based quantification of TRECs for 471 healthy control patients and 18 patients with SCID with various genetic abnormalities (IL2RG, JAK3, ADA, LIG4, RAG1) were performed, including patients with maternal T-cell engraftment (n = 4) and leaky T cells (n = 3).nnnRESULTSnTRECs were detectable in all normal neonatal Guthrie cards (n = 326) at the levels of 10(4) to 10(5) copies/microg DNA. In contrast, TRECs were extremely low in all neonatal Guthrie cards (n = 15) and peripheral blood (n = 14) from patients with SCID, including those with maternal T-cell engraftment or leaky T cells with hypomorphic RAG1 mutations or LIG4 deficiency. There were no false-positive or negative results in this study.nnnCONCLUSIONnTRECs quantification can be used as a neonatal mass screening for patients with SCID.

Modified Atkins diet therapy for a case with glucose transporter type 1 deficiency syndrome

Glucose transporter type 1 deficiency syndrome (GLUT-1 DS), giving rise to impaired glucose transport across the blood-brain barrier, is characterized by infantile seizures, complex motor disorders, global developmental delay, acquired microcephaly, and hypoglycorrhachia. GLUT-1 DS can be treated effectively with a ketogenic diet because it can provide an alternative fuel for brain metabolism; however, the excessive restriction of food intake involved frequently makes it difficult for patients to initiate or continue the diet. Recently, the modified Atkins diet, which is much less restrictive in terms of the total calorie and protein intake than the classical ketogenic diet, has been shown to be effective and well tolerated in children with intractable epilepsy. We successfully introduced the modified Atkins diet to a 7-year-old boy with GLUT-1 DS, whose caregivers refused ketogenic diet treatment because of strong concerns over restricting the diet. The modified Atkins diet should be considered for patients with GLUT-1 DS as an alternative to the traditional ketogenic diet.

TRH therapy in a patient with juvenile Alexander disease

Alexander disease is a rare disorder of the central nervous system caused by a de novo mutation in the glial fibrillary acidic protein (GFAP) gene. Unlike the much more common infantile form, the juvenile form is slowly progressive with bulbar, pyramidal and cerebellar signs. Herein, we report a 9-year old Japanese girl suffering from frequent vomiting, slurred speech and truncal ataxia. Juvenile Alexander disease was diagnosed by genetic analysis, which detected a novel GFAP mutation, D360V. We also describe our clinical success in treating this patient with thyrotropin releasing hormone (TRH).

Benefits of FK 506 for refractory eye symptoms in a young child with ocular myasthenia gravis

Recently, there have been many reports on the efficacy and safety of tacrolimus (FK506) treatment for adult patients with intractable generalized myasthenia gravis (MG). There have also been a few reports of successful FK506 therapy in patients with severe childhood-onset generalized MG involving a myasthenic crisis. Herein, we report the efficacy of FK 506 for refractory ocular symptoms in a 3-year-old girl with ocular type MG. Ptosis and alternating strabismus had appeared at 10 months of age. No bulbar signs, respiratory failure or generalized muscle weakness had been seen during her course. Her ocular symptoms had persisted despite repeated steroid pulse therapy, high dose oral prednisolone and thymectomy. Adverse effects of steroids, including obesity, growth retardation, osteoporosis, cataracts and hyperlipidemia, gradually worsened. After obtaining written informed consent from her parents, we started oral tacrolimus at a dose of 0.5mg/day and her symptoms resolved completely within 3 weeks at a maximum dose of 2.5mg/day. No adverse effects, such as renal failure or glucose intolerance, were seen. FK506 treatment allowed the steroid dose to be reduced, eliminating its adverse effects. In patients with intractable childhood-onset MG with ocular manifestations, FK506 is an alternative to steroid therapy or thymectomy.

Creatine monohydrate therapy in a Leigh syndrome patient with A8344G mutation

Mitochondrial encephalomyopathies, including Leigh syndrome (subacute necrotizing encephalomyelopathy), are progressive degenerative disorders that often involve multiple organs. 1 A number of treatments have been tried with mitochondrial encephalomyopathies, including vitamins B 1 , B 2 , C, and E, 2 coenzyme Q 10 , 2 dichloroacetate 3 and l-arginine, 4 but there is still no defi nitive therapy. Creatine monohydrate supplementation has been reported to give clinical improvement in some diseases with gyrate atrophy, in guanidinoacetate methyltransferase defi ciency 5

Close monitoring of initial enzyme replacement therapy in a patient with childhood-onset Pompe disease

Pompe disease is classified into infantile and late-onset (childhood and adult) forms based on onset age and degree of organ involvement. While benefits of enzyme replacement therapy (ERT) for the infantile form have been confirmed, efficacy for late-onset forms reportedly varies. We report close monitoring of initial ERT, focusing especially on the first year, in a 12-year-old boy with childhood-onset Pompe disease. At age 10, he started ERT at 20 mg/kg every other week. Respiratory and motor functions were evaluated at each infusion, and by skeletal muscle computed tomography (CT) and cardiac echography every 4 months. He gained the ability to climb stairs without a rail and % vital capacity improved just 1.5 months after starting ERT. Grip power, manual muscle testing (MMT) and the timed and 6-min walking distance tests (6MWT) improved promptly, paralleling improvements in clinical symptoms. However, this steady improvement stopped around 8 months, with deterioration to the initial level by about 24 months. Antibody against recombinant human alpha-glucosidase was very low at 15 months; therefore, the lack of treatment response did not completely correspond to antibody production. On the other hand, cardiac wall thickening worsened after 4 months, then improved to better than baseline after 8 months, and this improvement was well maintained. Among our set parameters, the timed test results corresponded better to his changing clinical course than did grip power, MMT or 6-min walking test results.

Severe muscle damage following viral infection in patients with Fukuyama congenital muscular dystrophy

Fukuyama congenital muscular dystrophy (FCMD), which is characterized by cortical migration defect and eye abnormalities, is the most common subtype of CMD in Japan. Fukutin (FKTN), the responsible gene for FCMD, encodes a protein involved in the glycosylation of alpha-dystroglycan. We have experienced some patients with FCMD who showed sudden exacerbation of muscle weakness with marked elevation of serum creatine kinase (CK) and urinary myoglobin levels a few days after a febrile episode of viral infection, occasionally leading to death. To describe this peculiar phenomenon, we focused on 12 patients who developed a sudden exacerbation of muscle weakness among 96 genetically defined FCMD patients and hospitalized because of a febrile illness at Tokyo Womens Medical University between 1997 and 2008. All the 12 patients were homozygous for a 3-kb insertion mutation of FKTN. The patients developed exacerbation of muscle weakness ranging from paralysis to loss of head control. The onset was concentrated in summer, and coxsackieviruses and enteroviruses were most often detected, especially in infantile patients. Eight of the 12 patients were treated with corticosteroids and recovered within 2 weeks. Four patients were treated without steroid, and needed 18.5 days on mean for improvement. None developed renal failure. The reason for muscle damage induced by viral infection remains unknown; however, physicians should consider its risk, sometimes leading to death, and draw it to parents attention, especially in the defervescent stage.

High-density areas on muscle CT in childhood-onset Pompe disease are caused by excess calcium accumulation

We report two patients with childhood-onset Pompe disease showing striking changes with high-density areas on skeletal muscle CT, not seen in adult- or infantile-onset forms of this disease. While the anterior compartment of the thigh muscles was less affected in the adult-onset form, the rectus femoris and tibial muscles were preferentially involved from the early stage in the childhood-onset form of Pompe disease. The high-density areas became increasingly diffuse with disease progression, producing a marbled pattern and ultimately resulting in homogeneous high density and muscle atrophy. Muscle biopsy specimens from the high-density areas showed striking vacuolar changes with many dense globular bodies in lysosomes. High calcium signals were identified by X-ray microanalysis using energy-dispersive X-ray spectroscopy in these areas. Excess calcium accumulation in the vacuoles was also confirmed with the glyoxal-bis(2-hydroxyanil) (GBHA) staining. The high density on CT was slightly reduced together with clinical improvement after enzyme replacement therapy in patient 2. Our data demonstrate that in childhood-onset Pompe disease, high-density areas on skeletal muscle CT images are due to the accumulation of calcium in dense globular bodies formed by a chronic degenerative process affecting autophagic vacuoles.

Respiratory management of patients with Fukuyama congenital muscular dystrophy

BACKGROUNDnFukuyama congenital muscular dystrophy (FCMD), characterized by intellectual impairment associated with cortical migration defects, is an autosomal recessive disorder caused by mutation in the fukutin gene. It is the second most common type of muscular dystrophy in Japan. Respiratory dysfunction, along with cardiomyopathy, can be life-threatening in patients with advanced-stage FCMD. However, few reports have focused on this issue.nnnMETHODSnWe retrospectively studied respiratory dysfunction and therapeutic management in 48 genetically diagnosed FCMD patients (mean age 11.0 years; range 3.6-31.9 years).nnnRESULTSnMechanical ventilation was initiated at a median age of 12.1 years in 16 patients, 14 of whom received non-invasive positive pressure ventilation (NPPV) while the other 2 underwent tracheostomy with invasive ventilation (TIV). The two TIV cases had unexpectedly required the initiation of ventilatory support at the ages of 15.7 and 18.0 years, respectively, because of unsuccessful extubation followed by serious respiratory infections, despite rather good respiratory function before these episodes. Patients carrying a compound heterozygous founder mutation or with a severe phenotype tended to need ventilatory support 2-3 years earlier than homozygous patients and those with the typical or mild phenotype. Mechanical insufflation-exsufflation (MI-E) interventions were also employed in six patients with serious dysphagia and were well-tolerated in all cases.nnnCONCLUSIONnFor respiratory management, it is important to regularly evaluate respiratory function in FCMD patients over 10 years of age, since intellectual impairment and insomnia often mask the signs of respiratory dysfunction. Most patients, despite poor cooperation due to intellectual impairment, can tolerate NPPV and MI-E provided that a carefully worked-out plan is adopted.

High-density CT of muscle and liver may allow early diagnosis of childhood-onset Pompe disease.

Pompe disease is classified into infantile-, childhood- and adult-onset forms based on onset age and the degree of organ involvement. Differing from the infantile-onset form which is characterized by marked organ involvement, the childhood-onset form usually presents with muscle weakness and elevation of serum creatine kinase (CK), mimicking those of progressive muscular dystrophy. We report our successful early diagnosis and initiation of enzyme replacement therapy (ERT) in a young girl with childhood-onset Pompe disease before the development of skeletal muscle symptoms. She was referred to our hospital at the age of 2 years 4 months because of hyperCKemia detected incidentally. She was active and lacked developmental delay and muscle weakness; however, hepatomegaly was noted. The combination of high-density changes in the liver and skeletal muscle on computed tomography (CT) images was suggestive of glycogen storage disorder, especially childhood-onset Pompe disease. Low alpha-glucosidase (GAA) activity on dried blood spots facilitated the diagnostic process, and genetic analysis of GAA allowed a definitive diagnosis, without performing muscle biopsy. We promptly started ERT at the age of 2 years 6 months. After 1 year, she still had not developed any skeletal muscle symptoms, and serum CK level was almost normal. Since the efficacy of ERT is thought to depend on the extent of muscle damage at its commencement, we expect that ERT may have prevented the manifestation of skeletal muscle involvement in this patient.